Ultraviolet A/Riboflavin Crosslinked Collagen and Multiple Bioactive Ion Capsules for Enhanced Bone Tissue Engineering

The dissertation investigates the enhancement of bone tissue engineering (BTE) through ultraviolet A/riboflavin (UVA/R) crosslinked collagen scaffolds combined with a bioactive ion delivery system. Collagen scaffolds, while offering excellent biocompatibility and structural support, often face challenges such as rapid degradation and insufficient osteoinductivity. This research addresses these limitations by optimizing the UVA/R crosslinking process to significantly improve the mechanical strength, stability, and bioactivity of collagen matrices without compromising their biocompatibility. A key focus of the study is unraveling the UVA/R crosslinking mechanism, identifying tyrosine residues as critical crosslinking sites and riboflavin as a dual-function agent. This crosslinking approach outperforms chemical methods, achieving a superior balance of durability and degradability while preserving essential biological interactions. In addition, a novel encapsulation system for bioactive ions, incorporating copper, and magnesium within vaterite-calcite CaCO₃ particles, is developed. These ion-loaded capsules provide sustained release, enhancing osteogenesis and angiogenesis, critical for bone regeneration. The findings demonstrate that the integration of UVA/R crosslinked collagen with bioactive ion delivery creates an innovative composite material capable of addressing complex bone defects. In vitro and in vivo assessments highlight the scaffold's ability to support cellular activity, mitigate inflammation, and foster bone and vascular tissue formation. This dissertation contributes a comprehensive framework for advancing BTE, paving the way for effective and personalized therapeutic interventions for bone repair.