Weng Tingting, Yang Min, Zhang Wei, Jin Ronghua, Xia Sizhan, Zhang Manjia, Wu Pan, He Xiaojie, Han Chunmao, Zhao Xiong, Wang Xingang
Department of Burns & Wound Care Centre Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China.
The Key Laboratory of Severe Trauma and Burns of Zhejiang Province Hangzhou China.
Bioeng Transl Med. 2023 Jun 25;8(5):e10562. doi: 10.1002/btm2.10562. eCollection 2023 Sep.
The vascularization of dermal substitutes is a key challenge in efforts to heal deep skin defects. In this study, dual gene-activated dermal scaffolds (DGADSs-1) were fabricated by loading nanocomposite particles of polyethylenimine (PEI)/multiple plasmid DNAs (pDNAs) encoding vascular endothelial growth factor and angiopoietin-1 at a ratio of 1:1. In a similar manner, DGADSs-2 were loaded with a chimeric plasmid encoding both VEGF and Ang-1. In vitro studies showed that both types of DGADSs released PEI/pDNA nanoparticles in a sustained manner; they demonstrated effective transfection ability, leading to upregulated expression of VEGF and Ang-1. Furthermore, both types of DGADSs promoted fibroblast proliferation and blood vessel formation, although DGADSs-1 showed a more obvious promotion effect. A rat full-thickness skin defect model showed that split-thickness skin transplanted using a one-step method could achieve full survival at the 12th day after surgery in both DGADSs-1 and DGADSs-2 groups, and the vascularization time of dermal substitutes was significantly shortened. Compared with the other three groups of scaffolds, the DGADSs-1 group had significantly greater cell infiltration, collagen deposition, neovascularization, and vascular maturation, all of which promoted wound healing. Thus, compared with single-gene-activated dermal scaffolds, DGADSs show greater potential for enhancing angiogenesis. DGADSs with different loading modes also exhibited differences in terms of angiogenesis; the effect of loading two genes (DGADSs-1) was better than the effect of loading a chimeric gene (DGADSs-2). In summary, DGADSs, which continuously upregulate VEGF and Ang-1 expression, offer a new functional tissue-engineered dermal substitute with the ability to activate vascularization.
真皮替代物的血管化是治疗深度皮肤缺损的关键挑战。在本研究中，通过以1:1的比例负载编码血管内皮生长因子和血管生成素-1的聚乙烯亚胺（PEI）/多质粒DNA（pDNA）纳米复合颗粒，制备了双基因激活真皮支架（DGADSs-1）。以类似的方式，DGADSs-2负载了编码VEGF和Ang-1的嵌合质粒。体外研究表明，两种类型的DGADSs均能持续释放PEI/pDNA纳米颗粒；它们表现出有效的转染能力，导致VEGF和Ang-1的表达上调。此外，两种类型的DGADSs均促进成纤维细胞增殖和血管形成，尽管DGADSs-1表现出更明显的促进作用。大鼠全层皮肤缺损模型表明，采用一步法移植中厚皮片，DGADSs-1组和DGADSs-2组在术后第12天均能实现完全存活，且真皮替代物的血管化时间显著缩短。与其他三组支架相比，DGADSs-1组的细胞浸润、胶原沉积、新生血管形成和血管成熟程度均显著更高，所有这些均促进了伤口愈合。因此，与单基因激活真皮支架相比，DGADSs在增强血管生成方面具有更大的潜力。不同负载模式的DGADSs在血管生成方面也表现出差异；负载两个基因（DGADSs-1）的效果优于负载嵌合基因（DGADSs-2）的效果。总之，能够持续上调VEGF和Ang-1表达的DGADSs提供了一种具有激活血管化能力的新型功能性组织工程真皮替代物。
