Collagen type I is the most abundant form of collagen in human tissues and is composed of two identical α-1 type I chains and an α-2 type I chain organized in a triple helical structure. Specifically, recombinant human collagen type I α2 / COL1A2 can be produced by HEK-293 cells expression system. And a previous study has shown that recombinant human collagen type I α2 / COL1A2 promotes collagen synthesis, wound healing, and elastin production in normal human dermal fibroblasts (HDFs).