κ‐Carrageenan Scaffolds Incorporating Hydroxyapatite‐Coated Chitosan Nanoparticles for Bone Tissue Engineering and Controlled Rosuvastatin Release

Current treatments for critical-sized bone defects are often ineffective, necessitating advanced biomaterial scaffolds that can address this limitation. A key challenge in developing these scaffolds is achieving sustained, localized delivery of osteoinductive drugs, which is crucial for enhancing bone tissue regeneration within the defect site. This research engineered a novel κ-carrageenan-based composite scaffold incorporating hydroxyapatite-coated chitosan nanoparticles for regulated rosuvastatin release. Chitosan nanoparticles containing rosuvastatin were synthesized using a water-in-oil emulsion method and subsequently coated with hydroxyapatite. κ-carrageenan-based scaffolds were then fabricated with varying concentrations of nanoparticles (0%, 10%, 20%, and 30%) and evaluated for their physical and mechanical properties. They were also assessed for biocompatibility, osteogenic differentiation potential, and hemocompatibility. Notably, the hydroxyapatite coating increased the size of nanoparticles and enabled a stable, long-term release of rosuvastatin. Moreover, incorporating these nanoparticles into scaffolds further enhanced the sustained release profile appropriate for long-term bone healing. Scaffolds containing 20% nanoparticles demonstrated the highest mechanical strength and were selected for cell adhesion, proliferation, and differentiation studies. Alkaline phosphatase activity and alizarin red staining confirmed the scaffolds' ability to promote osteogenic differentiation. Hemocompatibility assessment revealed a low hemolysis percentage (< 5%) for the carrageenan-based scaffolds, indicating good blood compatibility. Overall, the developed composite scaffold exhibits promising biocompatibility and efficacy for the controlled delivery of rosuvastatin and the repair of bone defects.