In Vivo Evaluation of Low Density Region Bone Regeneration Utilizing Different PLGA/Collagen/Bioactive Ceramic Composite Grafting Materials

Objectives: The aim of this in vivo study is to qualitatively evaluate the bone regeneration in inlay defects of grafting materials of various polymeric/collagen/bioactive ceramic compositions.
Methods: The collagen, poly[lactic-co-glycolic acid] (PLGA) copolymer, and bioactive ceramic composites were tested in a sheep hip preclinical model. For that purpose, four defects were created with rotary instrumentation in the iliac bone. Defects without any graft materials served as negative control. After 12 weeks of healing, histological examinations and micro-computed tomography were used to examine the extent of bone growth.
Results: All composite material formulations presented biocompatible properties with different osseoconductivity levels and bone formation. For all groups, a bone bridge formed across the cortical bone defect and cancelloous bone healing progressed uneventfully. A significant amount of osteoblast and bone remodelling units (BRUs) were observed in the histological sections for all materials despite the qualitatively different healing patterns and degree of bone formation.
Conclusions: Collagen/poly[lactic-co-glycolic acid] (PLGA) copolymer/bioactive ceramic composites materials may be formulated as alternatives to other particulate grafting material formulations. Further research is warranted in order to systematically determine the three different materials’ ratios that would results in optimal low density bone site healing.