前期工作中我们已研制多种真皮替代物，可减轻瘢痕形成，然而过度纤维化尤其是创面挛缩仍严重影响外观与功能。进一步研究发现，结缔组织生长因子（CTGF）介导成纤维细胞转化为肌成纤维细胞是导致真皮替代物移植后挛缩的关键；挛缩过程中因炎性介质及局部微血管受压、狭窄，乏氧代谢增强，氧自由基含量显著增多。基于这一特殊的理化环境，本项目拟研制一种依赖氧自由基响应的“智能化”调控瘢痕形成及挛缩的真皮替代物。制备氧自由基敏感纳米粒，包裹特异性沉默CTGF mRNA的siRNA，分散在胶原－硫酸软骨素溶液中制备成新型真皮替代物，移植后随创面胶原过度沉积及挛缩，局部氧自由基增多，刺激纳米粒适时、适度地释放siRNA，显著提高治疗的靶向性及时空同步性，抑制成纤维细胞增殖、转化的同时有效避免创面愈合延迟等副作用，将为解决真皮替代物移植后过度纤维化及挛缩的难题提供新思路。

In previous work we have developed a variety of dermal substitutes that reduces scarring,however, excessive fibrosis and wound contracture remains serious impact on the appearance and function . Further study found that connective tissue growth factor (CTGF) mediated fibroblasts transferring into myofibroblasts is a key factor leading to dermal substitute contracture after transplantation. During the contracture , oxygen free radicals content increased significantly, due to inflammatory mediators and local microvascular stenosis, hypoxia metabolism.Based on this special environment , the project is envisaged to develop one new smart dermal substitute of oxygen free radical -dependent regulation of scarring and contracture .To Prepare oxygen free radicals sensitive nanoparticles which wraps siRNA to target CTGF mRNA,the nanoparticles are dispersed in collagen - chondroitin sulfate solution to prepare one novel dermal substitute, after transplantation local oxygen free radicals increase significantly with excessive collagen deposition and wound contracture , which stimulates nanoparticles to release siRNA timely , the proliferation of fibroblasts and myofibroblasts is inhibited, excessive fibrosis and contracture are reduced. This project will provide a new method and idea for improving the quality of the dermal substitute.