Type I collagen extracted from rat-tail and bovine Achilles tendon for dental application: A comparative study

Background: Collagen has attracted great interest as a biomaterial for various dental and medical uses. Objective: Investigate the characteristics and biocompatibility of type I collagen extracted from rat-tail tendon and bovine Achilles tendon for dental application. Materials and methods: Type-I collagen was extracted from rat-tail and bovine Achilles tendon using pepsin. The purity of collagen extracts was examined 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 (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Scanning electron microscope (SEM) illustrations of purified collagen alone and collagen with HGFs and HOKs were presented. A three-dimensional wound-healing model of fibroblast populated collagen lattice (FPCL) was used to determine the capability of both sources of collagen to induce wound healing in vitro. Cellular collagen lattices were fabricated to examine the contraction rate of these collagens. Results: The average yield of collagen extracted from rat-tail and bovine Achilles tendon were 21.8±14.9% and 5.4±0.4%, respectively. The SDS-PAGE analysis showed that the extracts were composed of alpha 1, alpha 2 and beta chains with little contamination of other small proteins. The MTT assay showed good proliferation of cells cultured with each collagen extract, indicating that collagen extracts were non-toxic to the cells. SEM and the FPCL analysis showed that both types of collagen were biocompatible with both HGFs and HOKs, inducing good contraction in the in vitro model. Conclusion: Type-I collagen extracted from rat-tail and bovine Achilles tendon appeared to be biocompatible with HGFs and HOKs. Both biomaterials may be of use in dental practice.