Construction of In Vitro-In Vivo Correlation (IVIVC) Degradation Evaluation Model of Absorbable PCL/β-TCP Alveolar Bone Repair Scaffold and Exploration of a Biosafety Evaluation Idea Based on “Homeostasis”

Abstract

Traditional in vivo degradation assessments for resorbable medical devices face challenges due to extreme durations, high costs, and a lack of criteria for reaching tissue-response steady states. This study investigates a 3D-printed PCL/β-TCP bone grafting scaffold by designing a model that correlates multi-stage in vitro accelerated degradation with in vivo implantation across a full 25-month timeline. This integrated approach allows for a systematic evaluation of safety and efficacy by overlapping key degradation stages. Results identified a distinct three-phase degradation pattern; the scaffold provided robust bone regeneration and maintained mechanical support for 18 months, exhibiting excellent osseointegration and biocompatibility throughout. Significantly, the correlation model identified a "risk peak" regarding safety and functionality during degradation. By utilizing this concept to evaluate tissue compatibility, the study provides the experimental evidence necessary to establish "tissue-response homeostasis." Ultimately, this research proposes a novel evaluation strategy rooted in homeostasis principles, significantly improving the reliability of long-term degradation predictions. It establishes an efficient performance validation pathway for clinical scenarios like alveolar bone repair and offers vital guidance for the development of regulatory systems for similar resorbable medical devices.