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Ricercatore t.d. art. 24 c. 3 lett. B
Dipartimento Scienze della Vita sede ex Scienze Farmaceutiche Via Campi 103

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2023 - Chronic cholesterol administration to the brain supports complete and long-lasting cognitive and motor amelioration in Huntington's disease [Articolo su rivista]
Birolini, Giulia; Valenza, Marta; Ottonelli, Ilaria; Talpo, Francesca; Minoli, Lucia; Cappelleri, Andrea; Bombaci, Mauro; Caccia, Claudio; Canevari, Caterina; Trucco, Arianna; Leoni, Valerio; Passoni, Alice; Favagrossa, Monica; Nucera, Maria Rosaria; Colombo, Laura; Paltrinieri, Saverio; Bagnati, Renzo; Duskey, Jason Thomas; Caraffi, Riccardo; Vandelli, Maria Angela; Taroni, Franco; Salmona, Mario; Scanziani, Eugenio; Biella, Gerardo; Ruozi, Barbara; Tosi, Giovanni; Cattaneo, Elena

: Evidence that Huntington's disease (HD) is characterized by impaired cholesterol biosynthesis in the brain has led to strategies to increase its level in the brain of the rapidly progressing R6/2 mouse model, with a positive therapeutic outcome. Here we tested the long-term efficacy of chronic administration of cholesterol to the brain of the slowly progressing zQ175DN knock-in HD mice in preventing ("early treatment") or reversing ("late treatment") HD symptoms. To do this we used the most advanced formulation of cholesterol loaded brain-permeable nanoparticles (NPs), termed hybrid-g7-NPs-chol, which were injected intraperitoneally. We show that one cycle of treatment with hybrid-g7-NPs-chol, administered in the presymptomatic ("early treatment") or symptomatic ("late treatment") stages is sufficient to normalize cognitive defects up to 5 months, as well as to improve other behavioral and neuropathological parameters. A multiple cycle treatment combining both early and late treatments ("2 cycle treatment") lasting 6 months generates therapeutic effects for more than 11 months, without severe adverse reactions. Sustained cholesterol delivery to the brain of zQ175DN mice also reduces mutant Huntingtin aggregates in both the striatum and cortex and completely normalizes synaptic communication in the striatal medium spiny neurons compared to saline-treated HD mice. Furthermore, through a meta-analysis of published and current data, we demonstrated the power of hybrid-g7-NPs-chol and other strategies able to increase brain cholesterol biosynthesis, to reverse cognitive decline and counteract the formation of mutant Huntingtin aggregates. These results demonstrate that cholesterol delivery via brain-permeable NPs is a therapeutic option to sustainably reverse HD-related behavioral decline and neuropathological signs over time, highlighting the therapeutic potential of cholesterol-based strategies in HD patients. DATA AVAILABILITY: This study does not include data deposited in public repositories. Data are available on request to the corresponding authors.

2023 - "Combo" Multi-Target Pharmacological Therapy and New Formulations to Reduce Inflammation and Improve Endogenous Remyelination in Traumatic Spinal Cord Injury [Articolo su rivista]
Moretti, Marzia; Caraffi, Riccardo; Lorenzini, Luca; Ottonelli, Ilaria; Sannia, Michele; Alastra, Giuseppe; Baldassarro, Vito Antonio; Giuliani, Alessandro; Duskey, Jason Thomas; Cescatti, Maura; Ruozi, Barbara; Aloe, Luigi; Vandelli, Maria Angela; Giardino, Luciana; Tosi, Giovanni; Calzà, Laura

Spinal cord injury (SCI) is characterized by a cascade of events that lead to sensory and motor disabilities. To date, this condition is irreversible, and no cure exists. To improve myelin repair and limit secondary degeneration, we developed a multitherapy based on nanomedicines (NMeds) loaded with the promyelinating agent triiodothyronine (T3), used in combination with systemic ibuprofen and mouse nerve growth factor (mNGF). Poly-L-lactic-co-glycolic acid (PLGA) NMeds were optimized and loaded with T3 to promote sustained release. In vitro experiments confirmed the efficacy of T3-NMeds to differentiate oligodendrocyte precursor cells. In vivo rat experiments were performed in contusion SCI to explore the NMed biodistribution and efficacy of combo drugs at short- and long-term post-lesion. A strong anti-inflammatory effect was observed in the short term with a reduction of type M1 microglia and glutamate levels, but with a subsequent increase of TREM2. In the long term, an improvement of myelination in NG2-IR, an increase in MBP content, and a reduction of the demyelination area were observed. These data demonstrated that NMeds can successfully be used to obtain more controlled local drug delivery and that this multiple treatment could be effective in improving the outcome of SCIs.

2023 - Nanowired Delivery of Curcumin Attenuates Methamphetamine Neurotoxicity and Elevates Levels of Dopamine and Brain-Derived Neurotrophic Factor [Capitolo/Saggio]
Ottonelli, Ilaria; Sharma, Aruna; Ruozi, Barbara; Tosi, Giovanni; Duskey, Jason Thomas; Vandelli, Maria Angela; Lafuente, José Vicente; Nozari, Ala; Muresanu, Dafin Fior; Buzoianu, Anca Dana; Tian, Z Ryan; Zhang, Zhiqiang; Li, Cong; Feng, Lianyuan; Wiklund, Lars; Sharma, Hari Shanker

: Curcumin is a well-known antioxidant used as traditional medicine in China and India since ages to treat variety of inflammatory ailments as a food supplement. Curcumin has antitumor properties with neuroprotective effects in Alzheimer's disease. Curcumin elevates brain-derived neurotrophic factor (BDNF) and dopamine (DA) levels in the brain indicating its role in substance abuse. Methamphetamine (METH) is one of the most abused substances in the world that induces profound neurotoxicity by inducing breakdown of the blood-brain barrier (BBB), vasogenic edema and cellular injuries. However, influence of curcumin on METH-induced neurotoxicity is still not well investigated. In this investigation, METH neurotoxicity and neuroprotective effects of curcumin nanodelivery were examined in a rat model. METH (20 mg/kg, i.p.) neurotoxicity is evident 4 h after its administration exhibiting breakdown of BBB to Evans blue albumin in the cerebral cortex, hippocampus, cerebellum, thalamus and hypothalamus associated with vasogenic brain edema as seen measured using water content in all these regions. Nissl attaining exhibited profound neuronal injuries in the regions of BBB damage. Normal curcumin (50 mg/kg, i.v.) 30 min after METH administration was able to reduce BBB breakdown and brain edema partially in some of the above brain regions. However, TiO2 nanowired delivery of curcumin (25 mg/kg, i.v.) significantly attenuated brain edema, neuronal injuries and the BBB leakage in all the brain areas. BDNF level showed a significant higher level in METH-treated rats as compared to saline-treated METH group. Significantly enhanced DA levels in METH-treated rats were also observed with nanowired delivery of curcumin. Normal curcumin was able to slightly elevate DA and BDNF levels in the selected brain regions. Taken together, our observations are the first to show that nanodelivery of curcumin induces superior neuroprotection in METH neurotoxicity probable by enhancing BDNF and DA levels in the brain, not reported earlier.

2023 - Optimization of an Injectable Hydrogel Depot System for the Controlled Release of Retinal-Targeted Hybrid Nanoparticles [Articolo su rivista]
Ottonelli, I.; Bighinati, A.; Adani, E.; Loll, F.; Caraffi, R.; Vandelli, M. A.; Boury, F.; Tosi, G.; Duskey, J. T.; Marigo, V.; Ruozi, B.

A drawback in the development of treatments that can reach the retina is the presence of barriers in the eye that restrain compounds from reaching the target. Intravitreal injections hold promise for retinal delivery, but the natural defenses in the vitreous can rapidly degrade or eliminate therapeutic molecules. Injectable hydrogel implants, which act as a reservoir, can allow for long-term drug delivery with a single injection into the eye, but still suffer due to the fast clearance of the released drugs when traversing the vitreous and random diffusion that leads to lower pharmaceutic efficacy. A combination with HA-covered nanoparticles, which can be released from the gel and more readily pass through the vitreous to increase the delivery of therapeutic agents to the retina, represents an advanced and elegant way to overcome some of the limitations in eye drug delivery. In this article, we developed hybrid PLGA-Dotap NPs that, due to their hyaluronic acid coating, can improve in vivo distribution throughout the vitreous and delivery to retinal cells. Moreover, a hydrogel implant was developed to act as a depot for the hybrid NPs to better control and slow their release. These results are a first step to improve the treatment of retinal diseases by protecting and transporting the therapeutic treatment across the vitreous and to improve treatment options by creating a depot system for long-term treatments.

2023 - Recent Advances on Surface-Modified GBM Targeted Nanoparticles: Targeting Strategies and Surface Characterization [Articolo su rivista]
Rodà, Francesca; Caraffi, Riccardo; Picciolini, Silvia; Tosi, Giovanni; Vandelli, Maria Angela; Ruozi, Barbara; Bedoni, Marzia; Ottonelli, Ilaria; Duskey, Jason Thomas

Glioblastoma multiforme (GBM) is the most common malignant brain tumor, associated with low long-term survival. Nanoparticles (NPs) developed against GBM are a promising strategy to improve current therapies, by enhancing the brain delivery of active molecules and reducing off-target effects. In particular, NPs hold high potential for the targeted delivery of chemotherapeutics both across the blood-brain barrier (BBB) and specifically to GBM cell receptors, pathways, or the tumor microenvironment (TME). In this review, the most recent strategies to deliver drugs to GBM are explored. The main focus is on how surface functionalizations are essential for BBB crossing and for tumor specific targeting. We give a critical analysis of the various ligand-based approaches that have been used to target specific cancer cell receptors and the TME, or to interfere with the signaling pathways of GBM. Despite the increasing application of NPs in the clinical setting, new methods for ligand and surface characterization are needed to optimize the synthesis, as well as to predict their in vivo behavior. An expert opinion is given on the future of this research and what is still missing to create and characterize a functional NP system for improved GBM targeting.

2022 - Applications of the ROS-Responsive Thioketal Linker for the Production of Smart Nanomedicines [Articolo su rivista]
Rinaldi, A.; Caraffi, R.; Grazioli, M. V.; Oddone, N.; Giardino, L.; Tosi, G.; Vandelli, M. A.; Calza, L.; Ruozi, B.; Duskey, J. T.

Reactive oxygen species (ROS)-sensitive drug delivery systems (DDS) specifically responding to altered levels of ROS in the pathological microenvironment have emerged as an effective means to enhance the pharmaceutical efficacy of conventional nanomedicines, while simultaneously reducing side effects. In particular, the use of the biocompatible, biodegradable, and non-toxic ROS-responsive thioketal (TK) functional group in the design of smart DDS has grown exponentially in recent years. In the design of TK-based DDS, different technological uses of TK have been proposed to overcome the major limitations of conventional DDS counterparts including uncontrolled drug release and off-target effects. This review will focus on the different technological uses of TK-based biomaterials in smart nanomedicines by using it as a linker to connect a drug on the surface of nanoparticles, form prodrugs, as a core component of the DDS to directly control its structure, to control the opening of drug-releasing gates or to change the conformation of the nano-systems. A comprehensive view of the various uses of TK may allow researchers to exploit this reactive linker more consciously while designing nanomedicines to be more effective with improved disease-targeting ability, providing novel therapeutic opportunities in the treatment of many diseases.

2022 - Glioblastoma Multiforme Selective Nanomedicines for Improved Anti-Cancer Treatments [Articolo su rivista]
Duskey, J. T.; Rinaldi, A.; Ottonelli, I.; Caraffi, R.; De Benedictis, C. A.; Sauer, A. K.; Tosi, G.; Vandelli, M. A.; Ruozi, B.; Grabrucker, A. M.

Glioblastoma Multiforme (GBM) is a devastating disease with a low survival rate and few efficacious treatment options. The fast growth, late diagnostics, and off-target toxicity of currently used drugs represent major barriers that need to be overcome to provide a viable cure. Nanomedicines (NMeds) offer a way to overcome these pitfalls by protecting and loading drugs, increasing blood half-life, and being targetable with specific ligands on their surface. In this study, the FDA-approved polymer poly (lactic-co-glycolic) acid was used to optimise NMeds that were surface modified with a series of potential GBM-specific ligands. The NMeds were fully characterised for their physical and chemical properties, and then in vitro testing was performed to evaluate cell uptake and GBM cell specificity. While all targeted NMeds showed improved uptake, only those decorated with the-cell surface vimentin antibody M08 showed specificity for GBM over healthy cells. Finally, the most promising targeted NMed candidate was loaded with the well-known chemotherapeutic, paclitaxel, to confirm targeting and therapeutic effects in C6 GBM cells. These results demonstrate the importance of using well-optimised NMeds targeted with novel ligands to advance delivery and pharmaceutical effects against diseased cells while minimising the risk for nearby healthy cells.

2022 - Melatonin loaded hybrid nanomedicine: DoE approach, optimization and in vitro study on diabetic retinopathy model [Articolo su rivista]
Romeo, Alessia; Bonaccorso, Angela; Carbone, Claudia; Lupo, Gabriella; Daniela Anfuso, Carmelina; Giurdanella, Giovanni; Caggia, Cinzia; Randazzo, Cinzia; Russo, Nunziatina; Romano, Giovanni Luca; Bucolo, Claudio; Rizzo, Milena; Tosi, Giovanni; Thomas Duskey, Jason; Ruozi, Barbara; Pignatello, Rosario; Musumeci, Teresa

Melatonin (MEL) is a pleiotropic neurohormone of increasing interest as a neuroprotective agent in ocular dis-eases. Improving the mucoadhesiveness is a proposed strategy to increase the bioavailability of topical formu-lations. Herein, the design and optimization of MEL-loaded lipid-polymer hybrid nanoparticles (mel-LPHNs) using Design of Experiment (DoE) was performed. LPHNs consisted of PLGA-PEG polymer nanoparticles coated with a cationic lipid-shell. The optimized nanomedicine showed suitable size for ophthalmic administration (189.4 nm; PDI 0.260) with a positive surface charge (+39.8 mV), high encapsulation efficiency (79.8 %), suitable pH and osmolarity values, good mucoadhesive properties and a controlled release profile. Differential Scanning Calorimetry and Fourier-Transform Infrared Spectroscopy confirmed the encapsulation of melatonin in the systems and the interaction between lipids and polymer matrix. Biological evaluation in an in vitro model of diabetic retinopathy demonstrated enhanced neuroprotective and antioxidant activities of mel-LPHNs, compared to melatonin aqueous solution at the same concentration (0.1 and 1 mu M). A modified Draize test was performed to assess the ocular tolerability of the formulation showing no signs of irritation. To the best our knowledge, this study reported for the first time the development of mel-LPHNs, a novel and safe hybrid platform suitable for the topical management of retinal diseases.

2022 - Quantitative comparison of the protein corona of nanoparticles with different matrices [Articolo su rivista]
Ottonelli, Ilaria; Duskey, Jason Thomas; Genovese, Filippo; Pederzoli, Francesca; Caraffi, Riccardo; Valenza, Marta; Tosi, Giovanni; Vandelli, Maria Angela; Ruozi, Barbara

: Nanoparticles (NPs) are paving the way for improved treatments for difficult to treat diseases diseases; however, much is unknown about their fate in the body. One important factor is the interaction between NPs and blood proteins leading to the formation known as the "protein corona" (PC). The PC, consisting of the Hard (HC) and Soft Corona (SC), varies greatly based on the NP composition, size, and surface properties. This highlights the need for specific studies to differentiate the PC formation for each individual NP system. This work focused on comparing the HC and SC of three NPs with different matrix compositions: a) polymeric NPs based on poly(lactic-co-glycolic) acid (PLGA), b) hybrid NPs consisting of PLGA and Cholesterol, and c) lipidic NPs made only of Cholesterol. NPs were formulated and characterized for their physico-chemical characteristics and composition, and then were incubated in human plasma. In-depth purification, identification, and statistical analysis were then performed to identify the HC and SC components. Finally, similar investigations demonstrated whether the presence of a targeting ligand on the NP surface would affect the PC makeup. These results highlighted the different PC fingerprints of these NPs, which will be critical to better understand the biological influences of the PC and improve future NP designs.

2022 - Tunneling Nanotubes: A New Target for Nanomedicine? [Articolo su rivista]
Ottonelli, I.; Caraffi, R.; Tosi, G.; Vandelli, M. A.; Duskey, J. T.; Ruozi, B.

Tunneling nanotubes (TNTs), discovered in 2004, are thin, long protrusions between cells utilized for intercellular transfer and communication. These newly discovered structures have been demonstrated to play a crucial role in homeostasis, but also in the spreading of diseases, infections, and metastases. Gaining much interest in the medical research field, TNTs have been shown to transport nanomedicines (NMeds) between cells. NMeds have been studied thanks to their advantageous features in terms of reduced toxicity of drugs, enhanced solubility, protection of the payload, prolonged release, and more interestingly, cell-targeted delivery. Nevertheless, their transfer between cells via TNTs makes their true fate unknown. If better understood, TNTs could help control NMed delivery. In fact, TNTs can represent the possibility both to improve the biodistribution of NMeds throughout a diseased tissue by increasing their formation, or to minimize their formation to block the transfer of dangerous material. To date, few studies have investigated the interaction between NMeds and TNTs. In this work, we will explain what TNTs are and how they form and then review what has been published regarding their potential use in nanomedicine research. We will highlight possible future approaches to better exploit TNT intercellular communication in the field of nanomedicine.

2021 - Glioblastoma: State of the Art of Treatments and Applications of Polymeric and Lipidic Nanomedicines [Capitolo/Saggio]
Sgarbi, V.; Duskey, J. T.; Ottonelli, I.; Da Ros, F.; Oddone, N.; Vandelli, M. A.; Forni, F.; Tosi, G.; Ruozi, B.

Glioblastoma multiforme (GBM) is one of the most devastating tumors affecting more than 5 in 100,000 people. Unfortunately, its diagnosis is often discovered in late stages and is normally deadly, having a life expectancy of 12–15 months and a mere 3% of the affected patients living 3 years or more independent of race, sex, and age. Sadly, current treatments (i.e., chemotherapy, radiation, surgery) are extremely aggressive and extend the patient’s life by little more than a year on average. Even when treatment appears successful, relapse is often experienced. These extreme treatments, combined with their lack of long-term success, call for new innovations. Among them, nanomedicine becomes one of the most promising approaches regarding possible applications in advancing or ameliorating GBM management. In this chapter, we will therefore analyze the state of the art and the most novel and outstanding innovation in terms of diagnosis and treatment options.

2021 - Insights into kinetics, release, and behavioral effects of brain-targeted hybrid nanoparticles for cholesterol delivery in Huntington's disease [Articolo su rivista]
Birolini, Giulia; Valenza, Marta; Ottonelli, Ilaria; Passoni, Alice; Favagrossa, Monica; Duskey, Jason T; Bombaci, Mauro; Vandelli, Maria Angela; Colombo, Laura; Bagnati, Renzo; Caccia, Claudio; Leoni, Valerio; Taroni, Franco; Forni, Flavio; Ruozi, Barbara; Salmona, Mario; Tosi, Giovanni; Cattaneo, Elena

Supplementing brain cholesterol is emerging as a potential treatment for Huntington's disease (HD), a genetic neurodegenerative disorder characterized, among other abnormalities, by inefficient brain cholesterol biosynthesis. However, delivering cholesterol to the brain is challenging due to the blood-brain barrier (BBB), which prevents it from reaching the striatum, especially, with therapeutically relevant doses. Here we describe the distribution, kinetics, release, and safety of novel hybrid polymeric nanoparticles made of PLGA and cholesterol which were modified with an heptapeptide (g7) for BBB transit (hybrid-g7-NPs-chol). We show that these NPs rapidly reach the brain and target neural cells. Moreover, deuterium-labeled cholesterol from hybrid-g7-NPs-chol is released in a controlled manner within the brain and accumulates over time, while being rapidly removed from peripheral tissues and plasma. We confirm that systemic and repeated injections of the new hybrid-g7-NPs-chol enhanced endogenous cholesterol biosynthesis, prevented cognitive decline, and ameliorated motor defects in HD animals, without any inflammatory reaction. In summary, this study provides insights about the benefits and safety of cholesterol delivery through advanced brain-permeable nanoparticles for HD treatment.

2021 - Microfluidic technology for the production of hybrid nanomedicines [Articolo su rivista]
Ottonelli, I.; Duskey, J. T.; Rinaldi, A.; Grazioli, M. V.; Parmeggiani, I.; Vandelli, M. A.; Wang, L. Z.; Prud'Homme, R. K.; Tosi, G.; Ruozi, B.

Microfluidic technologies have recently been applied as innovative methods for the production of a variety of nanomedicines (NMeds), demonstrating their potential on a global scale. The capacity to precisely control variables, such as the flow rate ratio, temperature, total flow rate, etc., allows for greater tunability of the NMed systems that are more standardized and automated than the ones obtained by well-known benchtop protocols. However, it is a crucial aspect to be able to obtain NMeds with the same characteristics of the previously optimized ones. In this study, we focused on the transfer of a production protocol for hybrid NMeds (H-NMeds) consisting of PLGA, Cholesterol, and Pluronic® F68 from a benchtop nanoprecipitation method to a microfluidic device. For this aim, we modified parameters such as the flow rate ratio, the concentration of core materials in the organic phase, and the ratio between PLGA and Cholesterol in the feeding organic phase. Outputs analysed were the chemico–physical properties, such as size, PDI, and surface charge, the composition in terms of %Cholesterol and residual %Pluronic® F68, their stability to lyophilization, and the morphology via atomic force and electron microscopy. On the basis of the results, even if microfluidic technology is one of the unique procedures to obtain industrial production of NMeds, we demonstrated that the translation from a benchtop method to a microfluidic one is not a simple transfer of already established parameters, with several variables to be taken into account and to be optimized.

2021 - Nanomedicine-based technologies and novel biomarkers for the diagnosis and treatment of Alzheimer’s disease: from current to future challenges [Articolo su rivista]
Cano, A.; Turowski, P.; Ettcheto, M.; Duskey, J. T.; Tosi, G.; Sanchez-Lopez, E.; Garcia, M. L.; Camins, A.; Souto, E. B.; Ruiz, A.; Marquie, M.; Boada, M.

Increasing life expectancy has led to an aging population, which has consequently increased the prevalence of dementia. Alzheimer's disease (AD), the most common form of dementia worldwide, is estimated to make up 50–80% of all cases. AD cases are expected to reach 131 million by 2050, and this increasing prevalence will critically burden economies and health systems in the next decades. There is currently no treatment that can stop or reverse disease progression. In addition, the late diagnosis of AD constitutes a major obstacle to effective disease management. Therefore, improved diagnostic tools and new treatments for AD are urgently needed. In this review, we investigate and describe both well-established and recently discovered AD biomarkers that could potentially be used to detect AD at early stages and allow the monitoring of disease progression. Proteins such as NfL, MMPs, p-tau217, YKL-40, SNAP-25, VCAM-1, and Ng / BACE are some of the most promising biomarkers because of their successful use as diagnostic tools. In addition, we explore the most recent molecular strategies for an AD therapeutic approach and nanomedicine-based technologies, used to both target drugs to the brain and serve as devices for tracking disease progression diagnostic biomarkers. State-of-the-art nanoparticles, such as polymeric, lipid, and metal-based, are being widely investigated for their potential to improve the effectiveness of both conventional drugs and novel compounds for treating AD. The most recent studies on these nanodevices are deeply explained and discussed in this review. Graphic Abstract: [Figure not available: see fulltext.]

2021 - Nanomedicines for brain diseases: Where we are and where we are going [Articolo su rivista]
Tosi, G.; Thomas Duskey, J.; Angela Vandelli, M.; Ruozi, B.

Graphical abstract [Formula: see text].

2021 - Nerve Growth Factor Biodelivery: A Limiting Step in Moving Toward Extensive Clinical Application? [Articolo su rivista]
Alastra, Giuseppe; Aloe, Luigi; Baldassarro, Vito Antonio; Calzà, Laura; Cescatti, Maura; Duskey, Jason Thomas; Focarete, Maria Letizia; Giacomini, Daria; Giardino, Luciana; Giraldi, Valentina; Lorenzini, Luca; Moretti, Marzia; Parmeggiani, Irene; Sannia, Michele; Tosi, Giovanni

Nerve growth factor (NGF) was the first-discovered member of the neurotrophin family, a class of bioactive molecules which exerts powerful biological effects on the CNS and other peripheral tissues, not only during development, but also during adulthood. While these molecules have long been regarded as potential drugs to combat acute and chronic neurodegenerative processes, as evidenced by the extensive data on their neuroprotective properties, their clinical application has been hindered by their unexpected side effects, as well as by difficulties in defining appropriate dosing and administration strategies. This paper reviews aspects related to the endogenous production of NGF in healthy and pathological conditions, along with conventional and biomaterial-assisted delivery strategies, in an attempt to clarify the impediments to the clinical application of this powerful molecule.

2021 - Tween® preserves enzyme activity and stability in PLGA nanoparticles [Articolo su rivista]
Duskey, J. T.; Ottonelli, I.; Rinaldi, A.; Parmeggiani, I.; Zambelli, B.; Wang, L. Z.; Prud'Homme, R. K.; Vandelli, M. A.; Tosi, G.; Ruozi, B.

Enzymes, as natural and potentially long-term treatment options, have become one of the most sought-after pharmaceutical molecules to be delivered with nanoparticles (NPs); however, their instability during formulation often leads to underwhelming results. Various molecules, including the Tween® polysorbate series, have demonstrated enzyme activity protection but are often used uncontrolled without optimization. Here, poly(lactic-co-glycolic) acid (PLGA) NPs loaded with β-glucosidase (β-Glu) solutions containing Tween® 20, 60, or 80 were compared. Mixing the enzyme with Tween® pre-formulation had no effect on particle size or physical characteristics, but increased the amount of enzyme loaded. More importantly, NPs made with Tween® 20:enzyme solutions maintained significantly higher enzyme activity. Therefore, Tween® 20:enzyme solutions ranging from 60:1 to 2419:1 mol:mol were further analyzed. Isothermal titration calorimetry analysis demonstrated low affinity and unquantifiable binding between Tween® 20 and β-Glu. Incorporating these solutions in NPs showed no effect on size, zeta potential, or morphology. The amount of enzyme and Tween® 20 in the NPs was constant for all samples, but a trend towards higher activity with higher molar rapports of Tween® 20:β-Glu was observed. Finally, a burst release from NPs in the first hour with Tween®:β-Glu solutions was the same as free enzyme, but the enzyme remained active longer in solution. These results highlight the importance of stabilizers during NP formulation and how optimizing their use to stabilize an enzyme can help researchers design more efficient and effective enzyme loaded NPs.

2020 - Development and biocompatibility assessments of poly(3-hydroxybutyrate-co-ε-caprolactone) microparticles for diclofenac sodium delivery [Articolo su rivista]
Musumeci, T.; Bonaccorso, A.; Carbone, C.; Impallomeni, G.; Ballistreri, A.; Duskey, J. T.; Puglisi, G.; Pignatello, R.

Osteoarthritis (OA) is a debilitating disease affecting joints and impairing the ability to perform everyday tasks. Current treatment regimens tend to provide little to no relief. Therefore, there is a huge need for alternative strategies to manage this painful condition. The delivery of anti-inflammatory drugs into an injured joint with the aim of eliminating articular inflammation and modulate cartilage damage could be a useful strategy to treat OA. Accordingly, the aim of this study is to prepare microparticles (MPs) from new biodegradable poly (3-hydroxybutyrate-co-ε-caprolactone) copolymers (PHBCL) for the potential intra-articular injection of Diclofenac sodium for OA treatment. MPs were prepared starting from copolymers having different molecular weights and an HB/CL molar ratio and studied for their morphologies and size distribution by scanning electron microscopy. Drug loading and encapsulation efficiency were also determined. The in vitro release profile was assessed by the dialysis bag technique and the kinetic profile was evaluated by using several mathematical models revealing a diffusion release mechanism. A1 polymer and related MPs, as representative of the group, were selected for further biological investigation. In vitro studies performed on CaCo-2 and Balb/3T3 cells showed no toxic effects at the desired concentrations as revealed by MTT, CFE and Comet assays.

2020 - Drug delivery across the blood–brain barrier: recent advances in the use of nanocarriers [Articolo su rivista]
Mulvihill, John JE; Cunnane, Eoghan M; Ross, Aisling M; Duskey, Jason T; Tosi, Giovanni; Grabrucker, Andreas M

The blood-brain barrier (BBB) has a significant contribution to homeostasis and protection of the CNS. However, it also limits the crossing of therapeutics and thereby complicates the treatment of CNS disorders. To overcome this limitation, the use of nanocarriers for drug delivery across the BBB has recently been exploited. Nanocarriers can utilize different physiological mechanisms for drug delivery across the BBB and can be modified to achieve the desired kinetics and efficacy. Consequentially, several nanocarriers have been reported to act as functional nanomedicines in preclinical studies using animal models for human diseases. Given the rapid development of novel nanocarriers, this review provides a comprehensive insight into the most recent advancements made in nanocarrier-based drug delivery to the CNS, such as the development of multifunctional nanomedicines and theranostics.

2020 - Enzyme Stability in Nanoparticle Preparations Part 1: Bovine Serum Albumin Improves Enzyme Function [Articolo su rivista]
Duskey, Jason Thomas; da Ros, Federica; Ottonelli, Ilaria; Zambelli, Barbara; Vandelli, Maria Angela; Tosi, Giovanni; Ruozi, Barbara

Enzymes have gained attention for their role in numerous disease states, calling for research for their efficient delivery. Loading enzymes into polymeric nanoparticles to improve biodistribution, stability, and targeting in vivo has led the field with promising results, but these enzymes still suffer from a degradation effect during the formulation process that leads to lower kinetics and specific activity leading to a loss of therapeutic potential. Stabilizers, such as bovine serum albumin (BSA), can be beneficial, but the knowledge and understanding of their interaction with enzymes are not fully elucidated. To this end, the interaction of BSA with a model enzyme B-Glu, part of the hydrolase class and linked to Gaucher disease, was analyzed. To quantify the natural interaction of beta-glucosidase (B-Glu,) and BSA in solution, isothermal titration calorimetry (ITC) analysis was performed. Afterwards, polymeric nanoparticles encapsulating these complexes were fully characterized, and the encapsulation efficiency, activity of the encapsulated enzyme, and release kinetics of the enzyme were compared. ITC results showed that a natural binding of 1:1 was seen between B-Glu and BSA. Complex concentrations did not affect nanoparticle characteristics which maintained a size between 250 and 350 nm, but increased loading capacity (from 6% to 30%), enzyme activity, and extended-release kinetics (from less than one day to six days) were observed for particles containing higher B-Glu:BSA ratios. These results highlight the importance of understanding enzyme:stabilizer interactions in various nanoparticle systems to improve not only enzyme activity but also biodistribution and release kinetics for improved therapeutic effects. These results will be critical to fully characterize and compare the effect of stabilizers, such as BSA with other, more relevant therapeutic enzymes for central nervous system (CNS) disease treatments.

2020 - Investigating Novel Syntheses of a Series of Unique Hybrid PLGA-Chitosan Polymers for Potential Therapeutic Delivery Applications [Articolo su rivista]
Duskey, Jason Thomas; Baraldi, Cecilia; Gamberini, Maria Cristina; Ottonelli, Ilaria; Da Ros, Federica; Tosi, Giovanni; Forni, Flavio; Vandelli, Maria Angela; Ruozi, Barbara

Discovering new materials to aid in the therapeutic delivery of drugs is in high demand. PLGA, a FDA approved polymer, is well known in the literature to form films or nanoparticles that can load, protect, and deliver drug molecules; however, its incompatibility with certain drugs (due to hydrophilicity or charge repulsion interactions) limits its use. Combining PLGA or other polymers such as polycaprolactone with other safe and positively-charged molecules, such as chitosan, has been sought after to make hybrid systems that are more flexible in terms of loading ability, but often the reactions for polymer coupling use harsh conditions, films, unpurified products, or create a single unoptimized product. In this work, we aimed to investigate possible innovative improvements regarding two synthetic procedures. Two methods were attempted and analytically compared using nuclear magnetic resonance (NMR), fourier-transform infrared spectroscopy (FT-IR), and dynamic scanning calorimetry (DSC) to furnish pure, homogenous, and tunable PLGA-chitosan hybrid polymers. These were fully characterized by analytical methods. A series of hybrids was produced that could be used to increase the suitability of PLGA with previously non-compatible drug molecules

2020 - Nanoparticles as carriers for drug delivery of macromolecules across the blood-brain barrier [Articolo su rivista]
Tosi, Giovanni; Duskey, J. T.; Kreuter, Jörg

Introduction: Current therapies of neurodegenerative or neurometabolic diseases are, to a large extent, hampered by the inability of drugs to cross the blood-brain barrier (BBB). This very tight barrier severely restricts the entrance of molecules from the blood into the brain, especially macromolecular substances (i.e. neurotrophic factors, enzymes, proteins, as well as genetic materials). Due to their size, physicochemical properties, and instability, the delivery of these materials is particularly difficult.Areas covered: Recent research showed that biocompatible and biodegradable nanoparticles possessing tailored surface properties can enable a delivery of drugs and specifically of macromolecules across the blood-brain barrier by using carrier systems of the brain capillary endothelium (Trojan Horse strategy). In the present review, the state-of-art of nanoparticle-mediated drug delivery of different macromolecular substances into the brain following intravenous injection is summarized, and different nanomedicines that are used to enable the transport of neurotrophic factors and enzymes across the blood-brain barrier into the CNS are critically analyzed.Expert opinion: Brain delivery of macromolecules by an intravenous application using nanomedicines is now a growing area of interest which could be really translated into clinical application if dedicated effort will be given to industrial scale-up production.

2020 - Novel peptide-conjugated nanomedicines for brain targeting: In vivo evidence [Articolo su rivista]
Duskey, J. T.; Ottonelli, I.; Da Ros, F.; Vilella, A.; Zoli, M.; Kovachka, S.; Spyrakis, F.; Vandelli, M. A.; Tosi, G.; Ruozi, B.

Central nervous system (CNS) compartments remain one of the most difficult districts for drug delivery. This is due to the presence of the blood–brain barrier (BBB) that hampers 90% of drug passage, dramatically requiring non-invasive treatment strategies. Here, for the first time, the use of opioid-derived deltorphin-derivative peptides to drive biodegradable and biocompatible polymeric (i.e. poly-lactide-co-glycolide, PLGA) nanomedicines delivery across the BBB was described. Opioid-derived peptides were covalently conjugated to furnish activated polymers which were further used for fluorescently tagged nanoformulations. Beyond reporting production, formulation methodology and full physico-chemical characterization, in vivo tests generated clear proof of BBB crossing and CNS targeting by engineered nanomedicines opening the research to further applications of drug delivery and targeting in CNS disease models.

2020 - PLGA-PEG-ANG-2 Nanoparticles for Blood-Brain Barrier Crossing: Proof-of-Concept Study [Articolo su rivista]
Hoyos-Ceballos, Gina P; Ruozi, Barbara; Ottonelli, Ilaria; Da Ros, Federica; Vandelli, Maria Angela; Forni, Flavio; Daini, Eleonora; Vilella, Antonietta; Zoli, Michele; Tosi, Giovanni; Duskey, Jason T; López-Osorio, Betty L

The treatment of diseases that affect the central nervous system (CNS) represents a great research challenge due to the restriction imposed by the blood-brain barrier (BBB) to allow the passage of drugs into the brain. However, the use of modified nanomedicines engineered with different ligands that can be recognized by receptors expressed in the BBB offers a favorable alternative for this purpose. In this work, a BBB-penetrating peptide, angiopep-2 (Ang-2), was conjugated to poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles through pre- and post-formulation strategies. Then, their ability to cross the BBB was qualitatively assessed on an animal model. Proof-of-concept studies with fluorescent and confocal microscopy studies highlighted that the brain-targeted PLGA nanoparticles were able to cross the BBB and accumulated in neuronal cells, thus showing a promising brain drug delivery system.

2020 - Synthesis, Characterization, and In Vitro Studies of an Reactive Oxygen Species (ROS)-Responsive Methoxy Polyethylene Glycol-Thioketal-Melphalan Prodrug for Glioblastoma Treatment [Articolo su rivista]
Oddone, N.; Boury, F.; Garcion, E.; Grabrucker, A. M.; Martinez, M. C.; Da Ros, F.; Janaszewska, A.; Forni, F.; Vandelli, M. A.; Tosi, G.; Ruozi, B.; Duskey, J. T.

Glioblastoma (GBM) is the most frequent and aggressive primary tumor of the brain and averages a life expectancy in diagnosed patients of only 15 months. Hence, more effective therapies against this malignancy are urgently needed. Several diseases, including cancer, are featured by high levels of reactive oxygen species (ROS), which are possible GBM hallmarks to target or benefit from. Therefore, the covalent linkage of drugs to ROS-responsive molecules can be exploited aiming for a selective drug release within relevant pathological environments. In this work, we designed a new ROS-responsive prodrug by using Melphalan (MPH) covalently coupled with methoxy polyethylene glycol (mPEG) through a ROS-cleavable group thioketal (TK), demonstrating the capacity to self-assembly into nanosized micelles. Full chemical-physical characterization was conducted on the polymeric-prodrug and proper controls, along with in vitro cytotoxicity assayed on different GBM cell lines and “healthy” astrocyte cells confirming the absence of any cytotoxicity of the prodrug on healthy cells (i.e. astrocytes). These results were compared with the non-ROS responsive counterpart, underlining the anti-tumoral activity of ROS-responsive compared to the non-ROS-responsive prodrug on GBM cells expressing high levels of ROS. On the other hand, the combination treatment with this ROS-responsive prodrug and X-ray irradiation on human GBM cells resulted in an increase of the antitumoral effect, and this might be connected to radiotherapy. Hence, these results represent a starting point for a rationale design of innovative and tailored ROS-responsive prodrugs to be used in GBM therapy and in combination with radiotherapy.

2019 - Nanomedicine against Aβ aggregation by β–sheet breaker peptide delivery: In vitro evidence [Articolo su rivista]
Pederzoli, F.; Ruozi, B.; Duskey, J.; Hagmeyer, S.; Sauer, A. K.; Grabrucker, S.; Coelho, R.; Oddone, N.; Ottonelli, I.; Daini, E.; Zoli, M.; Vandelli, M. A.; Tosi, G.; Grabrucker, A. M.

The accumulation of amyloid β (Aβ) triggers a cascade of toxic events in Alzheimer’s disease (AD). The KLVFF peptide can interfere with Aβ aggregation. However, the peptide suffers from poor bioavailability and the inability to cross the blood–brain barrier. In this work, we study the possibility of adopting nanomedicine to overcome KLVFF limits in biodistribution. We produced new engineered polymeric nanoparticles (NPs), and we evaluated the cellular toxicity of these NPs and validated that KVLFF peptides released by NPs show the same promising effects on AD pathology. Our results revealed the successful generation of KVLFF loaded NPs that, without significant effects on cell heath, are even more potent in reversing Aβ-induced pathologies compared to the free peptide. Therefore, NPs will significantly advance KVLFF treatment as a therapeutic option for AD.

2019 - Nanomedicine in Alzheimer's disease: Amyloid beta targeting strategy [Capitolo/Saggio]
Tosi, Giovanni; Pederzoli, Francesca; Belletti, Daniela; Vandelli, Maria Angela; Forni, Flavio; Duskey, Jason Thomas; Ruozi, Barbara

The treatment of Alzheimer's disease (AD) is up to today one of the most unsuccessful examples of biomedical science. Despite the high number of literature evidences detailing the multifactorial and complex etiopathology of AD, no cure is yet present on the market and the available treatments are only symptomatic. The reasons could be ascribed on two main factors: (i) lack of ability of the majority of drugs to cross the blood-brain barrier (BBB), thus excluding the brain for any successful therapy; (ii) lack of selectivity and specificity of drugs, decreasing the efficacy of even potent anti-AD drugs. The exploitation of specifically engineered nanomedicines planned to cross the BBB and to target the most “hot” site of action (i.e., β-amyloid) is one of the most interesting innovations in drug delivery and could reasonably represent an promising choice for possible treatments and even early-diagnosis of AD. In this chapter, we therefore outline the most talented approaches in AD treatment with a specific focus on the main advantages/drawbacks and future possible translation to clinic application.

2019 - ROS-responsive “smart” polymeric conjugate: Synthesis, characterization and proof-of-concept study [Articolo su rivista]
Oddone, N.; Pederzoli, F.; Duskey, J. T.; De Benedictis, C. A.; Grabrucker, A. M.; Forni, F.; Vandelli, M. A.; Ruozi, B.; Tosi, G.

New approaches integrating stimuli-responsive linkers into prodrugs are currently emerging. These “smart” prodrugs can enhance the effectivity of conventional prodrugs with promising clinical applicability. Oxidative stress is central to several diseases, including cancer. Therefore, the design of prodrugs that respond to ROS stimulus, allowing a selective drug release in this condition, is fairly encouraging. Aiming to investigate the ROS-responsiveness of prodrugs containing the ROS-cleavable moiety, Thioketal (TK), we performed proof-of-concept studies by synthesizing ROS-responsive conjugate, namely mPEG-TK-Cy5, through exploiting Cy5 fluorescent dye. We demonstrated that, differently to non-ROS-responsive control conjugate (mPEG-Cy5), mPEG-TK-Cy5 shows a selective release of Cy5 in response to ROS in both, ROS-simulated conditions and in vitro on glioblastoma cells. Our results confirm the applicability of TK-technology in the design of ROS-responsive prodrugs, which constitutes a promising approach in cancer treatment. The translatability of this technology for other diseases treatment makes this a highly relevant and promising approach.

2019 - Targeting Brain Disease in MPSII: Preclinical Evaluation of IDS-Loaded PLGA Nanoparticles [Articolo su rivista]
Rigon, Laura; Salvalaio, Marika; Pederzoli, Francesca; Legnini, Elisa; Duskey, Jason Thomas; D'Avanzo, Francesca; De Filippis, Concetta; Ruozi, Barbara; Marin, Oriano; Vandelli, Maria Angela; Ottonelli, Ilaria; Scarpa, Maurizio; Tosi, Giovanni; Tomanin, Rosella

Mucopolysaccharidosis type II (MPSII) is a lysosomal storage disorder due to the deficit of the enzyme iduronate 2-sulfatase (IDS), which leads to the accumulation of glycosaminoglycans in most organ-systems, including the brain, and resulting in neurological involvement in about two-thirds of the patients. The main treatment is represented by a weekly infusion of the functional enzyme, which cannot cross the blood-brain barrier and reach the central nervous system. In this study, a tailored nanomedicine approach based on brain-targeted polymeric nanoparticles (g7-NPs), loaded with the therapeutic enzyme, was exploited. Fibroblasts from MPSII patients were treated for 7 days with NPs loaded with the IDS enzyme; an induced IDS activity like the one detected in healthy cells was measured, together with a reduction of GAG content to non-pathological levels. An in vivo short-term study in MPSII mice was performed by weekly administration of g7-NPs-IDS. Biochemical, histological, and immunohistochemical evaluations of liver and brain were performed. The 6-weeks treatment produced a significant reduction of GAG deposits in liver and brain tissues, as well as a reduction of some neurological and inflammatory markers (i.e., LAMP2, CD68, GFAP), highlighting a general improvement of the brain pathology. The g7-NPs-IDS approach allowed a brain-targeted enzyme replacement therapy. Based on these positive results, the future aim will be to optimize NP formulation further to gain a higher efficacy of the proposed approach.

2018 - Hybrid nanoparticles as a new technological approach to enhance the delivery of cholesterol into the brain [Articolo su rivista]
Belletti, Daniela; Grabrucker, Andreas Martin; Pederzoli, Francesca; Menerath, Isabel; Vandelli, Maria Angela; Tosi, Giovanni; Duskey, Thomas Jason; Forni, Flavio; Ruozi, Barbara

Restoration of the Chol homeostasis in the Central Nervous System (CNS) could be beneficial for the treatment of Huntington's Disease (HD), a progressive, fatal, adult-onset, neurodegenerative disorder. Unfortunately, Chol is unable to cross the blood–brain barrier (BBB), thus a novel strategy for a targeted delivery of Chol into the brain is highly desired. This article aims to investigate the production of hybrid nanoparticles composed by Chol and PLGA (MIX-NPs) modified with g7 ligand for BBB crossing. We described the impact of ratio between components (Chol and PLGA) and formulation process (nanoprecipitation or single emulsion process) on physico-chemical and structural characteristics, we tested MIX-NPs in vitro using primary hippocampal cell cultures evaluating possible toxicity, uptake, and the ability to influence excitatory synaptic receptors. Our results elucidated that both formulation processes produce MIX-NPs with a Chol content higher that 40%, meaning that Chol is a structural particle component and active compound at the same time. The formulation strategy impacted the architecture and reorganization of components leading to some differences in Chol availability between the two types of g7 MIX-NPs. Our results identified that both kinds of MIX-NPs are efficiently taken up by neurons, able to escape lysosomes and release Chol into the cells resulting in an efficient modification in expression of synaptic receptors that could be beneficial in HD.

2017 - Current Strategies for the Delivery of Therapeutic Proteins and Enzymes to Treat Brain Disorders [Capitolo/Saggio]
Duskey, Jason T.; Belletti, Daniela; Pederzoli, Francesca; Vandelli, Maria Angela; Forni, Flavio; Ruozi, Barbara; Tosi, Giovanni

Brain diseases and injuries are growing to be one of the most deadly and costly medical conditions in the world. Unfortunately, current treatments are incapable of ameliorating the symptoms let alone curing the diseases. Many brain diseases have been linked to a loss of function in a protein or enzyme, increasing research for improving their delivery. This is no easy task due to the delicate nature of proteins and enzymes in biological conditions, as well as the many barriers that exist in the body ranging from those in circulation to the more specific barriers to enter the brain. Several main techniques are being used (physical delivery, protein/enzyme conjugates, and nanoparticle delivery) to overcome these barriers and create new therapeutics. This review will cover recently published data and highlights the benefits and deficits of possible new protein or enzyme therapeutics for brain diseases.

2016 - Chaperonin–Dendrimer Conjugates for siRNA Delivery [Articolo su rivista]
Nussbaumer, M. G.; Duskey, J. T.; Rother, M.; Renggli, K.; Chami, M.; Bruns, N.

The group II chaperonin thermosome (THS) is a hollow protein nanoparticle that can encapsulate macromolecular guests. Two large pores grant access to the interior of the protein cage. Poly(amidoamine) (PAMAM) is conjugated into THS to act as an anchor for small interfering RNA (siRNA), allowing to load the THS with therapeutic payload. THS–PAMAM protects siRNA from degradation by RNase A and traffics KIF11 and GAPDH siRNA into U87 cancer cells. By modification of the protein cage with the cell-penetrating peptide TAT, RNA interference is also induced in PC-3 cells. THS–PAMAM protein–polymer conjugates are therefore promising siRNA transfection reagents and greatly expand the scope of protein cages in drug delivery applications.

2016 - Engineered non-toxic cationic nanocarriers with photo-triggered slow-release properties [Articolo su rivista]
Dinu, I. A.; Duskey, J. T.; Car, A.; Palivan, C. G.; Meier, W.

The charge density of polymers involved in drug delivery is a key parameter during cellular uptake; moreover, the nature of charged groups determines the encapsulation efficiency and nanocarrier stability. Unfortunately, the high toxicity and the burst release of loaded cargo are their major drawbacks. We have developed here a versatile strategy to design photo-responsive nanocarriers showing high stability, slow-release properties and low cytotoxicity. These delivery vehicles are intended to prolong the drug effect, reducing the dose frequency, decreasing the side effects and maintaining a proper level of the drug. Diblock copolymers based on poly(dimethylsiloxane) and poly(2-dimethylaminoethyl methacrylate) containing pendant photo-cleavable 2-nitrobenzyl moieties were synthesized by atom transfer radical polymerization and post-polymerization modification, and then self-assembled into nanoparticles. Dynamic light scattering and transmission electron microscopy showed that the size and morphology of nanoparticles were not affected by UV exposure. Nanoparticle cytotoxicity was evaluated in relation to the number and nature of positively charged units. The nanocarriers containing copolymers with a longer charged block were successfully taken up by cells and were non-toxic both before and after irradiation up to 300 μg mL-1. The slow photo-induced release of a negatively charged molecule, sulforhodamine B, reveals that the delivery is controlled not only by the photo-triggered transformation of hydrophilic blocks from cationic to zwitterionic, but also by a combination of forces that induce the self-assembly but do not allow the disruption of nanoparticles. Results suggest that this polymeric system plays a promising role as a nanocarrier for sustained, triggered drug delivery, preserving the non-toxicity after release.

2016 - Stimuli-Responsive Codelivery of Oligonucleotides and Drugs by Self-Assembled Peptide Nanoparticles [Articolo su rivista]
Sigg, S. J.; Postupalenko, V.; Duskey, J. T.; Palivan, C. G.; Meier, W.

Ever more emerging combined treatments exploiting synergistic effects of drug combinations demand smart, responsive codelivery carriers to reveal their full potential. In this study, a multifunctional stimuli-responsive amphiphilic peptide was designed and synthesized to self-assemble into nanoparticles capable of co-bearing and -releasing hydrophobic drugs and antisense oligonucleotides for combined therapies. The rational design was based on a hydrophobic l-tryptophan-d-leucine repeating unit derived from a truncated sequence of gramicidin A (gT), to entrap hydrophobic cargo, which is combined with a hydrophilic moiety of histidines to provide electrostatic affinity to nucleotides. Stimuli-responsiveness was implemented by linking the hydrophobic and hydrophilic sequence through an artificial amino acid bearing a disulfide functional group (H3SSgT). Stimuli-responsive peptides self-assembled in spherical nanoparticles in sizes (100-200 nm) generally considered as preferable for drug delivery applications. Responsive peptide nanoparticles revealed notable nucleotide condensing abilities while maintaining the ability to load hydrophobic cargo. The disulfide cleavage site introduced in the peptide sequence induced responsiveness to physiological concentrations of reducing agent, serving to release the incorporated molecules. Furthermore, the peptide nanoparticles, singly loaded or coloaded with boron-dipyrromethene (BODIPY) and/or antisense oligonucleotides, were efficiently taken up by cells. Such amphiphilic peptides that led to noncytotoxic, reduction-responsive nanoparticles capable of codelivering hydrophobic and nucleic acid payloads simultaneously provide potential toward combined treatment strategies to exploit synergistic effects.

2015 - Analysis of Molecular Parameters Determining the Antimalarial Activity of Polymer-Based Nanomimics [Articolo su rivista]
Najer, A.; Thamboo, S.; Duskey, J. T.; Palivan, C. G.; Beck, H. -P.; Meier, W.

Malaria and other infectious diseases are major global public health problems, which need to be tackled using new technologies to cope with the lack of efficacious vaccines and emerging drug resistance. A recently developed anti-infectious concept based on nanomimics tested with Plasmodium falciparum is analyzed for the molecular parameters determining its applicability. Nanomimics - nanoscaled polymer-based mimics of host cell membranes - are designed with a reduced number of surface-exposed malaria parasite receptor molecules (heparin), resulting in less potent invasion inhibition as determined in antimalarial assays. In contrast, when shorter receptor molecules are used to form nanomimics, more molecules are needed to obtain nanomimic potency similar to nanomimics with longer receptor molecules. The interaction of heparin on nanomimics with the processed Plasmodium falciparum merozoite surface protein 1-42 (PfMSP142) have a high affinity, Kd = 12.1 ± 1.6 × 10-9 m, as measured by fluorescence cross-correlation spectroscopy (FCCS). This detailed characterization of nanomimics and their molecular variants are an important step towards defining and optimizing possible nanomimic therapies for infectious diseases. Modified nanomimics are tested for their invasion inhibition potency against malaria parasites. Polymer-based host cell membrane mimics (nanomimics) are designed with variable length and number of surface-exposed malaria receptor molecules (heparin). Furthmore, the interaction of nanomimics with a responsible parasite ligand is characterized in detail to define nanomimic activity.

2015 - Miniaturization of gene transfection assays in 384- and 1536-well microplates [Articolo su rivista]
Li, J.; Crowley, S. T.; Duskey, J.; Khargharia, S.; Wu, M.; Rice, K. G.

The miniaturization of gene transfer assays to either 384- or 1536-well plates greatly economizes the expense and allows much higher throughput when transfecting immortalized and primary cells compared with more conventional 96-well assays. To validate the approach, luciferase and green fluorescent protein (GFP) reporter gene transfer assays were developed to determine the influence of cell seeding number, transfection reagent to DNA ratios, transfection time, DNA dose, and luciferin dose on linearity and sensitivity. HepG2, CHO, and NIH 3T3 cells were transfected with polyethylenimine (PEI)-DNA in both 384- and 1536-well plates. The results established optimal transfection parameters in 384-well plates in a total assay volume of 35 μl and in 1536-well plates in a total assay volume of 8 μl. A luciferase assay performed in 384-well plates produced a Z′ score of 0.53, making it acceptable for high-throughput screening. Primary hepatocytes were harvested from mouse liver and transfected with PEI DNA and calcium phosphate DNA nanoparticles in 384-well plates. Optimal transfection of primary hepatocytes was achieved on as few as 250 cells per well in 384-well plates, with CaPO4 proving to be 10-fold more potent than PEI.

2015 - New concepts to fight oxidative stress: Nanosized three-dimensional supramolecular antioxidant assemblies [Articolo su rivista]
Richard, P. U.; Duskey, J. T.; Stolarov, S.; Spulber, M.; Palivan, C. G.

Introduction: Misregulation of reactive oxygen species and reactive nitrogen species by the bodys antioxidant system results in oxidative stress, which is known to be associated with aging, and involved in various pathologies including cancer, neurodegenerative and cardiovascular diseases. A large variety of low-molecular-weight (LMW) antioxidant compounds and antioxidant enzymes have been proposed to alleviate oxidative stress, but their therapeutic efficacy is limited by their solubility, stability or bioavailability. In this respect, nanoscience-based systems are expected to provide more efficient mitigation of oxidative stress. Areas covered: The main nanoscience-based three-dimensional (3D) supramolecular assemblies, decorated with, or entrapping antioxidant compounds, or which possess intrinsic antioxidant activity are discussed and illustrated with recent examples. Assemblies with different architectures and sizes in the nanometer range serve: i) to deliver LMW antioxidant compounds or enzymes; ii) as antioxidant systems due to their intrinsic activity; and recently iii) to provide a confined space where catalytic antioxidant reactions take place in situ (nanoreactors and artificial organelles). A few insights into the role of antioxidants in mitigating oxidative stress caused by therapeutic compounds or drug carriers are also discussed.Expert opinion: Several challenges must still be overcome in the development of 3D supramolecular assemblies to efficiently fight oxidative stress. First, an improvement of the assemblies properties and stability in biological conditions has to be addressed. Second, new systems based on the combination of biomolecules or mimics in supramolecular assemblies should provide multifunctionality, stimuli-responsiveness and targeting properties for a more efficient therapeutic effect. Third, comparative studies are necessary to evaluate these systems in a standardized manner both in vitro and in vivo.

2015 - PH-Triggered Reversible Multiple Protein-Polymer Conjugation Based on Molecular Recognition [Articolo su rivista]
Liu, J.; Postupalenko, V.; Duskey, J. T.; Palivan, C. G.; Meier, W.

Polymer conjugation for protein-based therapeutics has been developed extensively, but it still suffers from conjugation leading to decrease in protein activity and generates complexes with limited diversity due to general classical systems only incorporating one protein per each complex. Here we introduce a site-specific noncovalent protein-polymer conjugation, which can reduce the heterogeneity of the conjugates without disrupting protein function, while allowing for the modulation of binding affinity and stability, affecting the pH dependent binding of the number of proteins per polymer. We compared classical one protein-polymer conjugates with multiple protein-polymer conjugates using His-tagged enhanced yellow fluorescence protein (His6-eYFP) and metal-coordinated tris-nitrilotriacetic acid (trisNTA-Men+) in a site-specific way. trisNTA-Men+-His6 acts as a reversible linker with pH-triggered release of functional protein from the trisNTA-functionalized copolymers. The nature of the selected Men+ and number of available trisNTA-Men+ on poly(N-isopropylacrylamide-co-tris-nitrilotriacetic acid acrylamide) (PNTn) copolymers enables predictable modulation of the conjugates binding affinity (0.09-1.35 μM), stability, cell toxicity, and pH responsiveness. This represents a promising platform that allows direct control over the properties of multiple protein-polymer conjugates compared to the classical single protein-polymer conjugates.

2015 - Structure-Activity Relationship of PEGylated Polylysine Peptides as Scavenger Receptor Inhibitors for Non-Viral Gene Delivery [Articolo su rivista]
Baumhover, N. J.; Duskey, J. T.; Khargharia, S.; White, C. W.; Crowley, S. T.; Allen, R. J.; Rice, K. G.

PEGylated polylysine peptides of the general structure PEG30 kDa-Cys-Trp-LysN (N = 10 to 30) were used to form fully condensed plasmid DNA (pGL3) polyplexes at a ratio of 1 nmol of peptide per μg of DNA (ranging from N:P 3:1 to 10:1 depending on Lys repeat). Co-administration of 5 to 80 nmols of excess PEG-peptide with fully formed polyplexes inhibited the liver uptake of 125I-pGL3-polyplexes. The percent inhibition was dependent on the PEG-peptide dose and was saturable, consistent with inhibition of scavenger receptors. The scavenger receptor inhibition potency of PEG-peptides was dependent on the length of the Lys repeat, which increased 10-fold when comparing PEG30 kDa-Cys-Trp-Lys10 (IC50 of 20.2 μM) with PEG30 kDa-Cys-Trp-Lys25 (IC50 of 2.1 μM). We hypothesize that PEG-peptides inhibit scavenger receptors by spontaneously forming small 40 to 60 nm albumin nanoparticles that bind to and saturate the receptor. Scavenger receptor inhibition delayed the metabolism of pGL3-polyplexes, resulting in efficient gene expression in liver hepatocytes following delayed hydrodynamic dosing. PEG-peptides represent a new class of scavenger inhibitors that will likely have broad utility in blocking unwanted liver uptake and metabolism of a variety of nanoparticles.

2014 - Nanoparticle ligand presentation for targeting solid tumors [Articolo su rivista]
Duskey, J. T.; Rice, K. G.

Among the many scientific advances to come from the study of nanoscience, the development of ligand-targeted nanoparticles to eliminate solid tumors is predicted to have a major impact on human health. There are many reports describing novel designs and testing of targeted nanoparticles to treat cancer. While the principles of the technology are well demonstrated in controlled lab experiments, there are still many hurdles to overcome for the science to mature into truly efficacious targeted nanoparticles that join the arsenal of agents currently used to treat cancer in humans. One of these hurdles is overcoming unwanted biodistribution to the liver while maximizing delivery to the tumor. This almost certainly requires advances in both nanoparticle stealth technology and targeting. Currently, it continues to be a challenge to control the loading of ligands onto polyethylene glycol (PEG) to achieve maximal targeting. Nanoparticle cellular uptake and subcellular targeting of genes and siRNA also remain a challenge. This review examines the types of ligands that have been most often used to target nanoparticles to solid tumors. As the science matures over the coming decade, careful control over ligand presentation on nanoparticles of precise size, shape, and charge will likely play a major role in achieving success.

2014 - PH-responsive PDMS-b-PDMAEMA micelles for intracellular anticancer drug delivery [Articolo su rivista]
Car, A.; Baumann, P.; Duskey, J. T.; Chami, M.; Bruns, N.; Meier, W.

A series of poly(dimethysiloxane)-b-poly(2-(dimethylamino)ethyl methacrylate) (PDMS-b-PDMAEMA) block copolymers were synthesized with atom transfer radical polymerization (ATRP). In aqueous solution the polymers self-assembled into micelles with diameters between 80 and 300 nm, with the ability to encapsulate DOX. The polymer with the shortest PDMAEMA block (5 units) displayed excellent cell viability, while micelles containing longer PDMAEMA block lengths (13 and 22 units) led to increased cytotoxicity. The carriers released DOX in response to a decrease in pH from 7.4 to 5.5. Confocal laser scanning microscopy (CLSM) revealed that nanoparticles were taken up by endocytosis into acidic cell compartments. Furthermore, DOX-loaded nanocarriers exhibited intracellular pH-response as changes in cell morphology and drug release were observed within 24 h.

2014 - The uptake mechanism of PEGylated DNA polyplexes by the liver influences gene expression [Articolo su rivista]
Khargharia, S.; Baumhover, N. J.; Crowley, S. T.; Duskey, J.; Rice, K. G.

Two uptake mechanisms were identified for PEGylated DNA polyplex biodistribution to the liver. At a low polyplex dose, a rapid-uptake mechanism dominates, resulting in 60% capture by liver in 5 min, due to a saturable receptor-mediated process. Rapid-uptake led to the fast metabolism of polyplexes by liver (t 1/2 =2.1 h), correlating with a 1-μg pGL3 polyplex dose losing full transfection competency after 4 h in the liver. Dose escalation of either polyplex or poly(ethylene glycol) (PEG) peptide led to the saturation of rapid-uptake and revealed a delayed-uptake mechanism for polyplexes by liver. Delayed-uptake was characterized by the slower liver accumulation of 40% of the polyplex dose over 40 min, followed by slow metabolism (t 1/2 =15 h) and an extended time (12 h) for a 1-μg pGL3 polyplex dose, remaining fully transfection competent in the liver. The delayed-uptake mechanism is consistent with polyplexes crossing liver fenestrated endothelial cells to reach steady state in the space of Disse. The results describe how to control polyplex biodistribution to liver to avoid rapid-uptake and metabolism, in favor of delayed-uptake, to preserve polyplex transfection competency in the liver for up to 12 h.

2011 - Metabolically stabilized long-circulating PEGylated polyacridine peptide polyplexes mediate hydrodynamically stimulated gene expression in liver [Articolo su rivista]
Fernandez, C. A.; Baumhover, N. J.; Duskey, J. T.; Khargharia, S.; Kizzire, K.; Ericson, M. D.; Rice, K. G.

A novel class of PEGylated polyacridine peptides was developed that mediate potent stimulated gene transfer in the liver of mice. Polyacridine peptides, (Acr-X) n-Cys-polyethylene glycol (PEG), possessing 2-6 repeats of Lys-acridine (Acr) spaced by either Lys, Arg, Leu or Glu, were Cys derivatized with PEG (PEG 5000 kDa) and evaluated as in vivo gene transfer agents. An optimal peptide of (Acr-Lys) 6-Cys-PEG was able to bind to plasmid DNA (pGL3) with high affinity by polyintercalation, stabilize DNA from metabolism by DNAse and extend the pharmacokinetic half-life of DNA in the circulation for up to 2 h. A tail vein dose of PEGylated polyacridine peptide pGL3 polyplexes (1 g in 50 l), followed by a stimulatory hydrodynamic dose of normal saline at times ranging from 5 to 60 min post-DNA administration, led to a high level of luciferase expression in the liver, equivalent to levels mediated by direct hydrodynamic dosing of 1 g of pGL3. The results establish the unique properties of PEGylated polyacridine peptides as a new and promising class of gene delivery peptides that facilitate reversible binding to plasmid DNA, protecting it from DNase in vivo resulting in an extended circulatory half-life, and release of transfection-competent DNA into the liver to mediate a high-level of gene expression upon hydrodynamic boost. © 2011 Macmillan Publishers Limited All rights reserved.