Design and evaluation of the biosafety and bioactivity of highly stable nano collagen

Abstract

The development of novel biomaterials has been a hot topic in the field of biomaterials research. Collagen, the most abundant protein in the extracellular matrix, has been widely utilized as a natural biomaterial; however, animal-derived collagen suffers from low thermal stability, ethical concerns and risks of pathogen transmission. Nano collagen (nCOL), synthesized via solid-phase peptide synthesis, has emerged as a promising alternative due to its defined sequence and strong capacity to mimic the structure and function of natural collagen; while their comprehensive biosafety and bioactivity remain to be fully explored. Herein, we have designed a highly stable nano collagen (nCOL), and for the first time evaluated its biosafety and bioactivity. The nCOL consisting of two terminal (GPO)₄ triplets and a central GFOGER motif, exhibits exceptional stability at both 25 °C and 37 °C, preserving its triple helical structural even after 10 days of protease digestion, significantly surpassing the stability of natural collagen. The residues of organic solvents and heavy metal ions in nCOL are well below the established pharmacopoeia standards, affirming its in vitro biosafety. Zebrafish, mice, and rabbits are employed to evaluate the in vivo biosafety of nCOL, demonstrating its exceptional safety profile. The bioactive assessments, including cell proliferation, adhesion, migration, zebrafish fin regeneration and anti-UV capabilities, demonstrate the capability of nCOL to promote tissue repair. This study provides a comprehensive understanding of nCOL's properties, offering robust support for its applications in tissue engineering and regenerative medicine.