Folic Acid-Conjugated PEG Nanoparticles for Controlled Delivery of Fasudil in Experimental Autoimmune Encephalomyelitis: A Proposed Model for Effective Multiple Sclerosis Therapy

Background : Effective delivery of therapeutic agents is crucial in modern medicine, especially as conventional treatments face challenges such as limited bioavailability, adverse side effects, and frequent dosing requirements. This study focuses on the synthesis and characterization of PLGA-PEG-folic acid (FA) nanoparticles loaded with Fasudil, a Rho-associated kinase (ROCK) inhibitor, to improve Experimental Autoimmune Encephalomyelitis (EAE) in a mouse model of multiple sclerosis (MS). Methods : The nanoparticles were synthesized by conjugating folic acid to PLGA-PEG-NH₂, followed by nanoprecipitation for drug encapsulation. Comprehensive characterization assessed particle size, zeta potential, morphology, and encapsulation efficiency to ensure optimal performance and stability. Drug release studies were performed under varying pH conditions to evaluate release kinetics. Additionally, inflammatory cytokine levels, immunohistochemical markers including Glial Fibrillary Acidic Protein (GFAP), Ionized Calcium-Binding Adapter Molecule 1 (IBA1), Myelin Basic Protein (MBP), and 5-bromo-2′-deoxyuridine (BrdU) expression were measured alongside demyelination rates. Results: The PLGA-PEG-FA nanoparticles exhibited an average size of 252 ± 5 nm and a zeta potential of –24.2 mV, indicating good stability, with an encapsulation efficiency of 64.29% for Fasudil. Release profiles were pH-dependent and best described by the Korsmeyer-Peppas model. Clinically, mice treated with PLGA-PEG-FA nanoparticles showed reduced inflammatory cytokine levels, decreased expression of GFAP and IBA1, and increased expression of MBP and BrdU. Conclusions: These results demonstrate that PLGA-PEG-FA nanoparticles effectively encapsulate and release Fasudil in a controlled manner and significantly ameliorate EAE symptoms, highlighting their potential as an efficient drug delivery system for neuroinflammatory diseases such as MS.