Photoreactive Hydrogels Based on Type I Collagen Extracted from Different Sources as Scaffolds for Tissue Engineering Applications: A Comparative Study

Abstract

Collagen-based hydrogels are promising constructs used frequently as scaffolds in various tissue engineering applications. The source of collagen extraction can influence the physiochemical properties, mechanical strength, as well as cellular behaviour of the tissue-engineered hydrogels. In the present study, type I collagen was isolated from three different animal sources, namely bovine Achilles tendon, bighead carp fish skin, and rat tail tendons. After characterizing the extracted collagens, their structures were modified via covalent functionalization of the free amines with methacrylate groups. Methacrylated collagens were combined with PEG-diacrylate to act as three-dimensional photocrosslinked scaffolds for culturing human corneal stromal cells. Physicochemical properties, mechanical strength, morphological features, and cellular behaviour were different depending on the collagen sources. Human corneal stromal cells more easily penetrated within hydrogels containing rat tail type I collagen, which also had greater pore sizes and porosity. However, the expressions of type I collagen and lumican were observed to be a greater extent in fish skin collagen-based hydrogels. Such observations highlight the significant effect of collagen extraction source on cellular behaviour and the importance of having a proper selection in accordance with the application of the tissue-engineered scaffold.