Abstract
Collagen is a biodegradable and biocompatible material, and has been applied in medical uses for decades. However, animal-derived collagens have several drawbacks, such as low thermal stability, nonspecific cell adhesion, and antigenicity. To solve these problems, preparing collagen-related biomaterial from short mimetic collagen peptides has received many attentions and become an emerging research topic. Our previous studies have shown that His-metal coordination can induce unstable short mimetic collagen peptides to assemble into a higher order structure. In this work, we prepared three collagen related peptides (CRPs): HG(POG)9GH, HG(POG)4PHG(POG)4GH, and GG(POG)9GG, of which two peptides contain His residues, to study their assembled structures. The size and topology of results show that His-metal coordination can promote mimetic collagen peptides to form macro-scale structures, and the topologies depend on metals and the time of adding metal ions into peptide solutions. Circular dichroism spectroscopy was used to examine the structure and the thermal stability of collagen mimetic peptides. Dynamic light scattering (DLS), SEM, and TEM were used to assess the size and the topology of the assembled structures. The CRPs in this work can form microstructures without the assistance of metal ions. Thus, pH dependent assembly of these CRPs was also examined. Although we are not able to clarify the process of self-assembly at the present stage, we did find the impact of the rate of self-assembly, His-metal coordination, and the His-His interaction on the assembly of CRPs. Our results may be useful and helpful for the future development of collagen-related materials.