National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, China.
J Mater Chem B. 2019 Jan 7;7(1):80-94. doi: 10.1039/c8tb01424h. Epub 2018 Dec 4.
The angiogenesis of an implanted construct is among the most important issues in tissue engineering. In this study, spermine was used to modify Bombyx mori silk fibroin (BSF) to synthesize cationized BSF (CBSF). BSF and CBSF were coated in sequence on the surface of polyethyleneimine (PEI)/vascular endothelial growth factor 165/angiopoietin-1 coexpression plasmid DNA (pDNA) complexes to form CBSF/BSF/PEI/pDNA quaternary complexes. BSF scaffolds loaded with carrier/pDNA complexes were prepared as dermal regeneration scaffolds by freeze-drying. In one set of experiments, scaffolds were used to cover a chick embryo chorioallantoic membrane (CAM) to investigate the influence of carrier/pDNA complexes on angiogenesis; in another set of experiments, scaffolds were implanted into dorsal full-thickness wounds in Sprague-Dawley rats to evaluate the effect of carrier/pDNA complex-loaded BSF scaffolds on neovascularization and dermal tissue regeneration. After modification with spermine, the surface zeta potential value of BSF rose to +11 mV from an initial value of -9 mV, and the isoelectric point of BSF increased from 4.20 to 9.04. The in vitro transfection of human umbilical vein endothelial cells (EA.hy926) with quaternary complexes revealed that the CBSF/BSF/PEI/pDNA complexes clearly exhibited lower cytotoxicity and higher transfection efficiency than the PEI/pDNA complexes. The CAM assay showed a more abundant branching pattern of blood vessels in BSF scaffolds loaded with CBSF/BSF/PEI/pDNA complexes than in BSF scaffolds without complexes or loaded with PEI/pDNA complexes. The in vivo experimental results demonstrated that the incorporation of CBSF/BSF/PEI/pDNA complexes could effectively enhance angiogenesis in the implanted BSF scaffolds, thereby promoting the regeneration of dermal tissue, providing a new scaffold for the regeneration of dermal tissue and other tissues containing blood vessels.
植入物的血管生成是组织工程中最重要的问题之一。在这项研究中，使用 spermine 修饰家蚕丝素纤维（BSF）以合成季铵化 BSF（CBSF）。BSF 和 CBSF 依次涂覆在聚乙烯亚胺（PEI）/血管内皮生长因子 165/血管生成素-1 共表达质粒 DNA（pDNA）复合物的表面上，形成 CBSF/BSF/PEI/pDNA 四元复合物。通过冷冻干燥制备负载载体/pDNA 复合物的 BSF 支架作为皮肤再生支架。在一组实验中，支架用于覆盖鸡胚绒毛尿囊膜（CAM）以研究载体/pDNA 复合物对血管生成的影响；在另一组实验中，支架被植入 Sprague-Dawley 大鼠的背部全层创面，以评估负载载体/pDNA 复合物的 BSF 支架对新血管形成和皮肤组织再生的影响。经过 spermine 修饰后，BSF 的表面 zeta 电位值从初始值-9 mV 上升到+11 mV，BSF 的等电点从 4.20 增加到 9.04。四元复合物对人脐静脉内皮细胞（EA.hy926）的体外转染表明，CBSF/BSF/PEI/pDNA 复合物明显表现出较低的细胞毒性和更高的转染效率，优于 PEI/pDNA 复合物。CAM 分析表明，负载 CBSF/BSF/PEI/pDNA 复合物的 BSF 支架中的血管分支模式更为丰富，而没有复合物或负载 PEI/pDNA 复合物的 BSF 支架则没有。体内实验结果表明，CBSF/BSF/PEI/pDNA 复合物的掺入可以有效增强植入 BSF 支架中的血管生成，从而促进皮肤组织的再生，为皮肤组织和其他含有血管的组织的再生提供了一种新的支架。
