Properties of collagen/sodium alginate hydrogels for bioprinting of skin models

3D printing technology has great potential for the reconstruction of human skin. However, the reconstructed skin has some differences from natural skin, largely because the hydrogel used does not have the appropriate biological and physical properties to allow healing and regeneration. This study examines the swelling, degradability, microstructure and biological properties of Collagen/Sodium Alginate (Col/SA) hydrogels of differing compositions for the purposes of skin printing. Increasing the content of sodium alginate causes the hydrogel to exhibit stronger mechanical and swelling properties, a faster degradation ratio, smaller pore size, and less favorable biological properties. An optimal 1% collagen hydrogel was used to print bi-layer skin in which fibroblasts and keratinocytes showed improved spreading and proliferation as compared to other developed formulations. The Col/SA hydrogels presented suitable tunability and properties to be used as a bioink for bioprinting of skin aiming at finding applications as 3D models for wound healing research.
This research was funded by the National Key R&D Program of China (2018YFE0207900), and People's Liberation Army (BWS17J036, 18-163-13-ZT-003-011-01) and the National Natural Science Foundation of China (51835010 and 51375371), and Xi’an Science and Technology Plan Project (21ZCZZHXJS-QCY6-0012). Shaanxi Science and Technology Project (2022KXJ-147). Thanks to Shi Changquan and Yang Chuncheng of Shaanxi Ketao-AM Technology Co., Ltd. for their technical support for printing equipment.