Optimized cloning and expression of recombinant human type I collagen in mammalian cells using Ubiquitous Chromatin Opening Elements for enhanced protein production

Collagen, a critical structural protein in the extracellular matrix, is widely used in biomedical applications, including tissue engineering, wound healing, and drug delivery systems. Recombinant human collagen offers significant advantages over animal-derived collagen, particularly in terms of biocompatibility and scalability. However, challenges remain in achieving high yields and ensuring proper post-translational modifications. This study aimed to optimize the expression of COL1A1 using Expi293F and HEK293T mammalian cell lines, with a focus on improving protein yield. By utilizing Ubiquitous Chromatin Opening Elements (UCOE) comprising mammalian expression vector, we achieved enhanced gene expression, leading to a 2.23-fold increase in COL1A1 production in Expi293F cells compared to HEK293T cells. Transient transfection of UCOE-COL1A1 constructs in Expi293F cells resulted in high-yield, endotoxin-free recombinant COL1A1 protein which was successfully purified using a Strep-Tag II affinity system. The protein exhibited proper C-terminal cleavage, confirming its functional integrity. These results highlight the advantages of Expi293F suspension culture for large-scale recombinant protein production and underscore the potential of UCOE vectors for optimizing gene expression in mammalian systems. Our study lays the groundwork for advancing recombinant collagen production, with implications for biomaterials, tissue engineering, and therapeutic interventions.