Higher order structure of short collagen model peptides attached to dendrimers and linear polymers.

Collagen, which is used as a biomaterial, is the most abundant protein in mammals. We have previously reported that a dendrimer modified with collagen model peptides, (Gly-Pro-Pro)(5), formed a collagen-like triple-helical structure, showing thermal reversibility. In this study, various collagen-mimic dendrimers of different generations and at different binding ratios were synthesized, to investigate the relationship between the peptide clustering effect and the higher order structure formation. The formation of the higher order structure was influenced by the binding ratios of the peptide to the dendrimer, but was not influenced by the dendrimer generation. A spacer, placed between the dendrimer terminal group and the peptide, negatively contributed to the formation of the higher order structure. The collagen model peptides were also attached to poly(allylamine) (PAA) and poly-L-lysine (poly(Lys)) to compare them with the collagen-mimic dendrimers. The PAA-based collagen-mimic compound, bearing more collagen model peptides than the dendrimer, exhibited a thermally stable higher order structure. In contrast, this was not observed for the collagen-mimic polymers based on poly(Lys). Therefore, dendrimers and vinyl polymers act as a scaffold for collagen model peptides and subsequently induce higher order structures.

A collagen-mimic dendrimer capable of controlled release.

A collagen model peptide-attached dendrimer was synthesized as a potential functional collagen material. The peptides that clustered at the surface of the dendrimer formed a thermally reversible collagen-like triple helix. This dendrimer worked as a drug carrier with thermosensitive release capabilities, although it did not exhibit a lower critical solution temperature. From this dendrimer, the hydrogel could be made at low temperature.