Biodegradable nanoparticles loaded with levodopa and/or curcumin for treatment of Parkinson’s disease

Abstract Background Parkinson’s disease (PD) is the second most common age-related neurodegenerative disorder. Levodopa (L-DOPA) remains the standard gold drug available for the treatment of PD. Curcumin has a wide range of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial, anti-amyloid, antitumor properties. Copolymers composed of poly(ethylene oxide) (PEO) and biodegradable polyesters like poly(ε-caprolactone) (PCL) that can self-assemble into nanoparticles (NP). This study describes the development of NH2-PEO-PCL diblock copolymer positively charged and modified by the addition of glutathione (GSH) on the outer surface, resulting in a synergistic delivery of L-DOPA and curcumin that would be able to pass the blood-brain barrier. Methods The NH2-PEO-PCL nanoparticles suspensions were prepared using a nanoprecipitation and solvent displacement method and were coated with GSH. NP was submitted to various characterizations assays, and to ensure the bioavailability, Vero and PC12 cells were treated with various concentrations of the loaded and unloaded NP to observe cytotoxicity. Results NP has successfully loaded L-DOPA and curcumin was stable after freeze-drying, capable of advancing into in vitro toxicity testing. After being treated up to 72 hours of various concentrations of L-DOPA and curcumin loaded NP Vero and PC12 cells, the viability of the treated cells maintained a high percentage indicating that the NPs are biocompatible. Conclusions NP consisting of NH2-PEO-PCL have been characterized as potential formulations for brain delivery of L-DOPA and curcumin, and obtained results also indicate that the developed biodegradable nanomicelles were blood compatible, presented low cytotoxicity even in longer exposure times.