title: Radiation cross-linked collagen/dextran dermal scaffolds: effects of dextran on cross-linking and degradation.
abstract: Ionizing radiation effectively cross-links collagen into network with enhanced anti-degradability and biocompatibility, while radiation-cross-linked collagen scaffold lacks flexibility, satisfactory surface appearance, and performs poor in cell penetration and ingrowth. To make the radiation-cross-linked collagen scaffold to serve as an ideal artificial dermis, dextran was incorporated into collagen. Scaffolds with the collagen/dextran (Col/Dex) ratios of 10/0, 7/3, and 5/5 were fabricated via (60)Co γ-irradiation cross-linking, followed by lyophilization. The morphology, microstructure, physicochemical, and biological properties were investigated. Compared with pure collagen, scaffolds with dextran demonstrated more porous appearance, enhanced hydrophilicity while the cross-linking density was lower with the consequence of larger pore size, higher water uptake, as well as reduced stiffness. Accelerated degradation was observed when dextran was incorporated in both the in vitro and in vivo assays, which led to earlier integration with cell and host tissue. The effect of dextran on degradation was ascribed to the decreased cross-linking density, looser microstructure, more porous and hydrophilic surface. Considering the better appearance, softness, moderate degradation rate due to controllable cross-linking degree and good biocompatibility as well, radiation-cross-linked collagen/dextran scaffolds are expected to serve as promising artificial dermal substitutes.
authors.affiliation: a Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies , Peking University , Beijing 100871 , China.
authors.forename: Yaqing
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiangmei
authors.initials: X
authors.lastname: Zhang
authors.forename: Ling
authors.initials: L
authors.lastname: Xu
authors.forename: Shicheng
authors.initials: S
authors.lastname: Wei
authors.forename: Maolin
authors.initials: M
authors.lastname: Zhai
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001458:Bandages; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D003094:Collagen / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects; D003911:Dextrans / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects; D004548:Elasticity; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D051379:Mice; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D011839:Radiation, Ionizing; D051381:Rats; D017768:Skin, Artificial; D017550:Spectroscopy, Fourier Transform Infrared; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014947:Wounds and Injuries / Q000473:pathology / Q000628:therapy
chemical_list: D003911:Dextrans; D014867:Water; D003094:Collagen
keywords: artificial dermal substitutes; collagen/dextran; dermal tissue engineering; radiation cross-linking; scaffolds