Journal of Bionic Engineering (2023) 20:105–118   https://doi.org/10.1007/s42235-022-00251-8

Properties of Collagen/Sodium Alginate Hydrogels for Bioprinting of Skin Models 

Tian Jiao1  · Qin Lian1,2 · Weilong Lian1  · Yonghui Wang1  · Dichen Li1  · Rui L. Reis3,4 · Joaquim Miguel Oliveira3,4 

1 State Key Laboratory for Manufacturing System Engineering, Xi’an Jiaotong University, Xi’an 710049, China
2 Shaanxi Ketao-AM Technology Co., Ltd., Xi’an 710100, China
3 3B’s Research Group, I3Bs—Research Institute on Biomaterials, Biodegradables and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Barco, 4805-017 Guimaraes, Portugal
4 ICVS/3B’s–PT Government Associate Laboratory, Barco, 4805-017 Guimaraes, Portugal

Abstract  3D printing technology has great potential for the reconstruction of human skin. However, the reconstructed skin has some diferences 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 difering 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 fbroblasts 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 fnding applications as 3D models for wound healing research. 

Keywords  Bioink · Bioprinting · Collagen/sodium alginate hydrogel · Skin · Wound healing · Bionic

Fig. 1 Schematic diagram of bioink preparation and skin printing