The Use of Collagen in a High Concentration for the Engeineering of Cartilage Tissue with 3D-Bioprinting
3D-bioprinting is a promising technology for tissue engineering structure formation in the case of damaged tissue and organ replacement. Collagen is one of the most appropriate hydrogels for the purpose, due to its exceptional biocompatibility. However, the use of collagen with conventionally low concentration makes bioprinting difficult and does not provide high accuracy. The purpose of this study was evaluation of suitability of collagen with high concentration in case of chondrocyte-laden scaffold fabrication via 3D-bioprinting for cartilage formation in vitro and in vivo. Immediately after the beginning of the scaffold incubation, cell migration to the surface and out of the scaffold was observed. The results of the study showed that the 4% porosity inherent for collagen is not enough for cells to survive in case of long-term incubation in vitro. The cells remaining in the collagen mostly died within 4 weeks. As for in vivo study, 2 weeks after implantation of the scaffold, a weak granulomatous inflammation was observed. After 6 weeks, connective tissue was formed in the area of implantation, where macrophages and the groups of small cells with rounded nuclei were found. In accordance with morphological criteria, these cells could be considered as young chondrocytes. However, their amount was not sufficient to start the formation of cartilage tissue.