title: From collagen-chitosan blends to three-dimensional scaffolds: the influences of chitosan on collagen nanofibrillar structure and mechanical property.
abstract: The nanofibrillar feature of native type I collagen is of great importance in maintaining its functions in vivo. In the field of engineering collagen-based materials in vitro, different fabrications may yield differences in collagen organization and thus affect the nanofibrous structure. Two approaches of fabricating collagen-chitosan (Col-Chi) scaffolds were presented in this study to investigate the respective impacts especially on nanostructures. Compared with glutaraldehyde cross-linking fabrications, thermally triggered cofibrillogenesis showed a preferred capability in fabricating favorable porous scaffolds and preserving uniform and orderly assembled nanofibrils. A detailed kinetic study of the cofibrillogenesis in thermally triggered approach was then carried out to reveal the possible factors affecting the final fibrillar structures. Zeta potential measurements in different Col-Chi blends with varying Chi/Col ratios indicated the influences of electrostatic interactions on the subsequent cofibrillogenesis process. The native D-periodicity of ∼64 nm was found on collagen fibrils in the presence of different amounts of chitosan by atomic force microscopy observation. The relevance of nanofibrillar structures to the overall performances of Col-Chi scaffolds was also revealed by assessing swelling behaviors and tensile measurements. The maximum tensile strength obtained in the thermally triggered scaffolds was up to ∼361.2 ± 32.3 kPa, emphasizing the significance of preserving biomimetic nanofibrillar structures in reconstruction of Col-Chi scaffolds.
authors.affiliation: National Engineering Research Center for Biomaterials, Sichuan University, Wangjiang Road 29, Chengdu 610064, PR China.
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Sang
authors.forename: Dongmei
authors.initials: D
authors.lastname: Luo
authors.forename: Xudong
authors.initials: X
authors.lastname: Li
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002417:Cattle; D048271:Chitosan / Q000737:chemistry*; D003094:Collagen / Q000737:chemistry* / Q000648:ultrastructure; D005976:Glutaral / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D016062:Porosity; D055672:Static Electricity; D013696:Temperature; D013718:Tensile Strength; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D003094:Collagen; D048271:Chitosan; D005976:Glutaral