Controllable preparation of hydrophilic alendronate hydroxyapatite quercetin multifunctional polylactic acid microspheres for treating osteoarthritis.

Osteoarthritis (OA) is a degenerative joint disease primarily caused by damage to the articular cartilage. During early OA pathogenesis, chondrocyte mitochondrial dysfunction drives reactive oxygen species (ROS) overproduction, and propagating oxidative damage. Therefore, maintaining a stable pH in the microenvironment and eliminating ROS are crucial for effectively treating OA. In this study, we aim to design a targeted small-molecule delivery system possessing excellent adhesion properties and microenvironment remediation capabilities, addressing the issues of drug degradation and loss in OA treatment. We obtained microspheres (PPC) exhibiting superior cell adhesion through carboxymethyl cellulose (CMC) surface modification. Subsequently, quercetin (QUE) was chelated with alendronate-functionalized hydroxyapatite via coordination bonds to obtain (AHQ) nanoparticles. The (PPC-AHQ) microspheres loaded with AHQ nanoparticles exhibit excellent performance in antioxidant and cell adhesion experiments. This study offers valuable insights into OA therapy based on small molecule delivery.