A Wet-Stable Collagen Scaffold For Gingival Regeneration

To address limitations of autologous grafts and the instability of collagen substitutes upon blood exposure, a wet-stable cross-linked collagen scaffold(AC) was developed and evaluated for gingival tissue regeneration. AC was created using a novel macromolecule for collagen cross-linking. It was characterized in vitro by electron microscopy, FTIR spectroscopy, and ninhydrin assay. Mechanical properties were evaluated in the wet state, and volume stability was assessed via water swelling, degradation, and blood clot stability tests. AC was co-cultured with human gingival fibroblasts and umbilical vein endothelial cells to examine cellular proliferation, adhesion, migration, and angiogenesis. Blood compatibility was confirmed by hemolysis testing. In vivo, biocompatibility, degradation, and angiogenic ability were examined via subcutaneous implantation in nude mice over 4, 8, and 14 weeks. Gingival tissue integration and regeneration were assessed at 1, 2, and 4 weeks post-implantation in rats. Tests were compared with commercial products FG and MG. AC formed a porous, interconnected network, exhibiting superior compressive elasticity and deformation recovery compared to MG, as well as higher tensile strength than FG. Additionally, AC enhanced cell adhesion and blood clot stability, demonstrated resistance to degradation with a hemolysis rate of less than 5%, and showed non-toxicity and enhanced angiogenesis compared to MG in nude mice. In rats, AC integrated seamlessly with gingival tissues, promoting connective tissue regeneration at 1 and 2 weeks, and exhibited greater degradation resistance than MG and FG at 4 weeks. AC is a biocompatible and promising alternative for gingival tissue regeneration.