Preparation of heat-induced artificial collagen gels based on collagen-mimetic dendrimers

Collagen, a major component of the extracellular matrix, contains Gly-Pro-Hyp repeats that form a hydrogel. In this study, artificial collagen-mimetic materials were designed. Synthetic dendritic macromolecules were fully modified with (Pro-Hyp-Gly)n and named collagen-mimetic dendrimers. A collagen-like triple helical structure was observed by circular dichroism spectrometry, with an efficiency that depended on the peptide length. A (Pro-Hyp-Gly)10-modified dendrimer exhibited the most efficient triple helix formation. Thermal stability was enhanced by clustering at the surface of the dendrimer. The (Pro-Hyp-Gly)10-modified dendrimer was assembled by heating and the assembly was affected by temperature, time and concentration. Hydrogels based on the (Pro-Hyp-Gly)10-modified dendrimer, but not on the peptide itself, were successfully prepared by heating. The sol–gel transition behavior was similar to natural collagen but not gelatin, which is thermally denatured collagen. Dynamic rheological analysis showed that the sol–gel transition temperature and the strength depended on the concentration. Thus, the collagen-mimetic dendrimer incorporating (Pro-Hyp-Gly)10 is an injectable and controllable artificial collagen gel.