Novel curcumin loaded nanoparticles engineered for blood-brain barrier crossing and able to disrupt Abeta aggregates

. The formation of extracellular aggregates built up by deposits of β-amyloid (Aβ) is a hallmark of Alzheimer’s disease (AD). Curcumin has been reported to display anti-amyloidogenic activity, not only by inhibiting the formation of new Aβ aggregates, but also by disaggregating existing ones. However, the uptake of Curcumin into the brain is severely restricted by its low ability to cross the blood-brain barrier (BBB). Therefore, novel strategies for a targeted delivery of Curcumin into the brain are highly desired. Here, we encapsulated Curcumin as active ingredient in PLGA (polylactide-co-glycolic-acid) nanoparticles (NPs), modified with g7 ligand for BBB crossing. We performed in depth analyses of possible toxicity of these NPs, uptake, and, foremost, their ability to influence Aβ pathology in vitro using primary hippocampal cell cultures. Our results show no apparent toxicity of the formulated NPs, but a significant decrease of Aβ aggregates in response to Curcumin loaded NPs. We thus conclude that brain delivery of Curcumin using BBB crossing NPs is a promising future approach in the treatment of AD

Antioxidant activity and photostability assessment of trans-resveratrol acrylate microspheres

<p>Trans-resveratrol (RSV) was microencapsulated in Eudragit^® RS100 and RL100 resin blends. Lyophilized microspheres were characterized in the solid state for their micromeritic properties and drug loading. FT-IR, PXRD, and DSC analyzes suggested that RSV formed an intimate microcrystalline dispersion within the polymer network, also confirmed by SEM analysis. This produced a reduced degradation of RSV after storage at 40 °C, compared to the neat drug, and a protection of the drug from UV light-induced trans-cis isomerization (60% intact drug was found after 60 s irradiation at 350 nm, compared to 37% for the pure drug). Solubility and <i>in vitro</i> dissolution studies indicated that microencapsulation did not improve the dissolution pattern of RSV in simulated gastric and intestinal aqueous fluids. Evaluation of the <i>in vitro</i> antioxidant activity showed that, compared to the neat drug in aqueous solution, RSV loaded in the microspheres retained for a longer time, up to 22 days of incubation, the initial ORAC capacity. The present study thus demonstrated that Eudragit^® Retard resins can be used to easily produce micro-sized solid dispersions with RSV, for potential oral administration, contributing to ameliorate the physico-chemical stability and antioxidant activity of this compound.</p

Hybrid nanoparticles as a new technological approach to enhance the delivery of cholesterol into the brain

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

Glioblastoma multiforme selective nanomedicines for improved anti-cancer treatments

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.</p

g7-NPs/Alb representative confocal images of Ids-ko and wt mice brain.

<p>(a) Ids-ko and (b) syngeneic wt mice. Nuclei are shown in blue (DAPI staining), NPs in red (rhodamine labeling), Albumin in green (FITC labeling); last column represents the merged images.</p

Synthesis, characterization, and In vitro studies of an reactive oxygen species (ROS)-responsive methoxy polyethylene glycol-thioketal- melphalan prodrug for glioblastoma treatment

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 thismalignancy 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-ROSresponsive 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

Morphologic characterization of nanoparticles.

<p>AFM (panels a, c, e) and SEM (panels b, d, f) images of unloaded g7-NPs, used as control, loaded u-NPs/Alb and g7-NPs/Alb, respectively. g7-NPs: unloaded targeted nanoparticles; u-NPs/Alb: untargeted nanoparticles loaded with albumin;g7-NPs/Alb: targeted nanoparticles loaded with albumin.</p

Type of injection performed in the two mouse models.

<p>Type of injection performed in the two mouse models.</p

Localization of g7-NPs/Alb in Idua-ko mouse brain.

<p>Representative confocal images of the g7-NPs/Alb perinuclear localization in the brain of Idua-ko mice injected with g7-NPs/Alb. (a) Albumin is shown in green (FITC labeling), (b) NPs in red (rhodamine labeling), (c) nuclei in blue (DAPI staining); (d) represents the merged images.</p

Number of g7-NPs/Alb in the brain of Ids-ko and wt mice.

<p>*p-value <0.001.</p