Synergistic Stabilization and Bioactivity Enhancement of Collagen by Dual-Terminal Fusion with a central Elastin-like Polypeptide.

The biomedical application of single-type collagens is often constrained by their limited structural stability and biological activity. To address these challenges, we designed a novel fusion protein, designated CEC, using a central elastin-like polypeptide (ELP) to link the human type I and type III collagens. This dual-terminal fusion strategy exploits ELP not only as a stable and soluble tag but also as a functional domain that operates synergistically with the collagen modules to augment stability and bioactivity. The CEC protein was efficiently expressed in a soluble form in a prokaryotic system, achieving a yield of 1.12g/L in unoptimized 10-L fermentation and a purity of 98% following a straightforward purification process. Structural characterization revealed that CEC retains a partial triple-helical conformation and demonstrates stability exceeding that of type III collagen (comparable to type I, with ≤1% degradation after 16 days at 37°C). In vitro assays showed that CEC significantly promoted fibroblast migration relative to type III collagen, while it markedly improved cell adhesion compared with both individual type I and type III collagens, without cytotoxic effects. In vivo, CEC accelerated re-epithelialization and promoted organized collagen deposition within 7-10 days; this accelerated wound closure relative to single collagens may reduce the risk of external infection. Collectively, the synergistic interplay between the ELP and collagen domains endows CEC with superior production efficiency, structural stability, and regenerative potency, establishing it as a highly promising high-efficacy biomaterial for clinical aesthetic and wound repair applications. The dual-terminal fusion approach further provides a versatile methodological framework for improving the properties of other types of recombinant collagen.