**Wen-Kui Song 1, Dan Liu 2, Lei-Lei Sun 3, Ba-Fang Li 1,\* and Hu Hou 1,\***


Received: 29 December 2018; Accepted: 20 February 2019; Published: 26 February 2019

**Abstract:** The aim of this study is to investigate the physicochemical properties, biosafety, and biocompatibility of the collagen extract from the skin of Nile tilapia, and evaluate its use as a potential material for biomedical applications. Two extraction methods were used to obtain acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from tilapia skin. Amino acid composition, FTIR, and SDS-PAGE results showed that ASC and PSC were type I collagen. The molecular form of ASC and PSC is (α1)2α2. The FTIR spectra of ASC and PSC were similar, and the characteristic peaks corresponding to amide A, amide B, amide I, amide II, and amide III were 3323 cm−1, 2931 cm−1, 1677 cm−1, 1546 cm−1, and 1242 cm−1, respectively. Denaturation temperatures (Td) were 36.1 ◦C and 34.4 ◦C, respectively. SEM images showed the loose and porous structure of collagen, indicting its physical foundation for use in applications of biomedical materials. Negative results were obtained in an endotoxin test. Proliferation rates of osteoblastic (MC3T3E1) cells and fibroblast (L929) cells from mouse and human umbilical vein endothelial cells (HUVEC) were increased in the collagen-treated group compared with the controls. Furthermore, the acute systemic toxicity test showed no acute systemic toxicity of the ASC and PSC collagen sponges. These findings indicated that the collagen from Nile tilapia skin is highly biocompatible in nature and could be used as a suitable biomedical material.

**Keywords:** Nile tilapia collagen; biomedical application; characterization
