Characterization of Type-I Collagen From Different Sources for Dental Application

Objective: To investigate the characteristics and biocompatibility of type I collagen extracted from different animal sources that can be developed for the use in dental application. Methods: Type-I collagen was extracted from rat tail, porcine Achilles tendon, and bovine Achilles tendon using pepsin. These collagen extracts were investigated for their purity using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The biocompatibility with human gingival fibroblasts (HGFs) and human oral keratinocytes (HOKs) was examined using an MTT assay. Scanning electron microscope (SEM) illustrations of purified collagen alone and collagen with HGFs were also presented. Three dimensional wound healing model, namely, fibroblast populated collagen lattice (FPCL) was also used to determine the capability of all three types of collagens to induce wound healing in vitro. Results: The average yield of extraction from rat tail, porcine Achilles tendon, and bovine Achilles tendon was 21.8%, 6.12% and 5.35%, respectively. From SDS-PAGE analysis, all collagen extracts were composed of alpha1, alpha 2 and beta chains with no contamination of small proteins. Collagen extracts appeared to be non-toxic since the MTT assay showed good proliferation of cells cultured. However, the proliferation rates of cells cultured with collagen were slightly less than that of control. Light microscopic pictures of collagen revealed that the type I collagen extracted from rat tail and porcine Achilles tendon seemed to be clearer than that of bovine collagen. SEM analysis showed good biocompatibility of HGFs and all collagen extracts. From the FPCL analysis, all three types of collagen were biocompatible with both cells and could induce good wound healing in this in vitro model. Conclusion: All collagens extracted from rat tail, porcine Achilles tendon, and bovine Achilles tendon appeared to have no cytotoxicity to HGFs and HOKs and should be further explored for the development of type I collagen for dental practice.