title: Enhanced angiogenesis of porous collagen scaffolds by incorporation of TMC/DNA complexes encoding vascular endothelial growth factor.
abstract: Angiogenesis of an implanted construct is one of the most important issues in tissue engineering and regenerative medicine, and can often take as long as several weeks. The vascular endothelial growth factor (VEGF) shows a positive effect on enhancing angiogenesis in vivo. But the incorporation of growth factors has many limitations, since they typically have half-lives only on the order of minutes. Therefore, in this work the DNA encoding VEGF was applied to enhance the angiogenesis of a collagen scaffold. A cationic gene delivery vector, N,N,N-trimethyl chitosan chloride (TMC), was used to form complexes with the plasmid DNA encoding VEGF. The complexes were then incorporated into the collagen scaffold, the loading being mediated by the feeding concentration and release in a sustained manner. In vitro cell culture demonstrated a significant improvement in the VEGF expression level from the TMC/DNA complexes containing scaffolds, in particular with a large amount of DNA. The scaffolds containing the TMC/DNA complexes were subcutaneously implanted into Sprague-Dawley mice to study their angiogenesis via macroscopic observation, hematoxylin-eosin staining and immunohistochemical staining. The results demonstrated that the incorporation of TMC/DNA complexes could effectively enhance the in vivo VEGF expression and thereby the angiogenesis of implanted scaffolds.
authors.affiliation: Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Mao
authors.forename: Haifei
authors.initials: H
authors.lastname: Shi
authors.forename: Rui
authors.initials: R
authors.lastname: Guo
authors.forename: Lie
authors.initials: L
authors.lastname: Ma
authors.forename: Changyou
authors.initials: C
authors.lastname: Gao
authors.forename: Chunmao
authors.initials: C
authors.lastname: Han
authors.forename: Jiacong
authors.initials: J
authors.lastname: Shen
mesh_terms: D043924:Angiogenesis Modulating Agents / Q000008:administration & dosage; D000818:Animals; D048271:Chitosan / Q000737:chemistry*; D003094:Collagen / Q000737:chemistry*; D004247:DNA / Q000008:administration & dosage / Q000235:genetics*; D004337:Drug Carriers / Q000737:chemistry*; D048091:Guided Tissue Regeneration / Q000379:methods; D008297:Male; D008422:Materials Testing; D051379:Mice; D018919:Neovascularization, Physiologic / Q000502:physiology*; D016062:Porosity; D014162:Transfection / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000502:physiology*
chemical_list: D043924:Angiogenesis Modulating Agents; D004337:Drug Carriers; C118071:N-trimethyl chitosan chloride; D042461:Vascular Endothelial Growth Factor A; D003094:Collagen; D004247:DNA; D048271:Chitosan