Chitosan-Grafted-Poly(N-vinylcaprolactam)-Decorated Fe3O4@SiO2 Core–Shell Nanoformulation as an Efficient Drug Delivery System for Poorly Soluble Drugs

Hydrocortisone, a commonly used anti-inflammatory drug, has limited aqueous solubility and several side effects. To address this challenge, as a proof-of-concept, this article demonstrates the development of a controlled-release drug delivery system (DDS) for hydrocortisone using chitosan-grafted poly(N-vinylcaprolactam) (CS-g-PNVCL)-coated core-shell Fe₃O₄@SiO₂ nanoformulations (NFs). Reported magnetic nanoparticles (NPs) were synthesized and modified with silica, PNVCL, and CS precursors to enhance the biocompatibility of DDS and drug-loading efficiency. The release rate of hydrocortisone from Fe₃O₄@SiO₂@CS-g-PNVCL NFs was observed to be higher at lower pH values, and the smart polymer coating demonstrated temperature responsiveness, facilitating drug release at higher temperatures. Fe₃O₄@SiO₂@CS-g-PNVCL NFs exhibited a cell viability of around 97.2 to 87.3% (5-100 μg/mL) after 24-48 h, while the hydrocortisone-NFs had a cell viability of around 93.2 to 82.3%. Our findings suggest that CS-g-PNVCL-coated Fe₃O₄@SiO₂ NPs effectively enhance the solubility, loading capacity, and targeted delivery of poorly soluble drugs, thereby improving their therapeutic efficacy and bioavailability.