Injectable hydrogels incorporating molecularly imprinted MgO/chitosan nanoparticles for controlled gentamicin delivery for potential cartilage-related applications

Cartilage repair remains a challenge because of the limited ability to self-heal and high risk of postoperative infection. We herein propose an injectable nanocomposite hydrogel comprising Pluronic F127/gelatin with gentamicin-loaded molecularly imprinted MgO/chitosan nanoparticles (MC-MIP-G). It was the first attempt to unite molecular imprinting and MgO-based nanoparticles within a thermoresponsive hydrogel for cartilage tissue engineering. Structural, morphological and compositional analyses (XRD, FTIR, TEM, EDS) proved the formation of nanoparticles with size of about 19 nm, comprising a crystalline MgO and a polymeric shell with efficient drug-encapsulation capability. Wettability of surfaces was suggested by the contact angle of ∼ 42°. Biological investigations using L929 fibroblast cells showed high cytocompatibility (>80% cell viability), low hemolysis (<5%), and acceptable coagulation indices. The drug release profile suggested near zero-order gentamicin release from the 5 wt% MC-MIP-G hydrogel to provide extended infection control. These findings clearly indicate the potential of F127/gelatin/MC-MIP-G hydrogels as multifunctional scaffolds for localized, infection-free cartilage regeneration. This study represents an in vitro proof-of-concept investigation, and further in vivo studies are required to validate cartilage regeneration efficacy and long-term functional performance.