title: Temperature-dependent higher order structures of the (Pro-Pro-Gly)₁₀-modified dendrimer.
abstract: Collagen is the most abundant protein in mammals and is widely used as a biomaterial for tissue engineering and drug delivery. We previously reported that dendrimers and linear polymers, modified with collagen model peptides (Pro-Pro-Gly)₅, form a collagen-like triple-helical structure; however, its triple helicity needs improvement. In this study, a collagen-mimic dendrimer modified with the longer collagen model peptides, (Pro-Pro-Gly)₁₀, was synthesized and named PPG10-den. Circular dichroism analysis shows that the efficiency of the triple helix formation in PPG10-den was much improved over the original. The X-ray diffraction analysis suggests that the higher order structure was similar to the collagen triple helix. The thermal stability of the triple helix in PPG10-den was higher than in the PPG10 peptide itself and our previous collagen-mimic polymers using (Pro-Pro-Gly)₅. Interestingly, PPG10-den also assembled at low temperatures. Self-assembled structures with spherical and rod-like shapes were observed by transmission electron microscopy. Furthermore, a hydrogel of PPG10-den was successfully prepared which exhibited the sol-gel transition around 45°C. Therefore, the collagen-mimic dendrimer is a potential temperature-dependent biomaterial.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Suehiro
authors.forename: Tomoko
authors.initials: T
authors.lastname: Tada
authors.forename: Tomonori
authors.initials: T
authors.lastname: Waku
authors.forename: Naoki
authors.initials: N
authors.lastname: Tanaka
authors.forename: Chizuru
authors.initials: C
authors.lastname: Hongo
authors.forename: Shinya
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakahira
authors.forename: Chie
authors.initials: C
authors.lastname: Kojima
mesh_terms: D002942:Circular Dichroism / Q000379:methods; D003094:Collagen / Q000138:chemical synthesis / Q000737:chemistry* / Q000648:ultrastructure*; D050091:Dendrimers / Q000737:chemistry; D055032:Electron Microscope Tomography / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods; D009842:Oligopeptides / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D011487:Protein Conformation; D013696:Temperature; D013816:Thermodynamics; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: C405243:(prolyl-prolyl-glycine)10; D050091:Dendrimers; D009842:Oligopeptides; D010455:Peptides; C044555:prolyl-prolyl-glycine; D003094:Collagen