低能近红外响应的载基因纳米粒水凝胶系统防治肌腱粘连的机制研究

The formation of adhesion during healing process of injured tendon seriously affects the recovery of hand functions. There is still no effective treatment. Studies reported that the formation of adhesions was inhibited by blocking TGF-β1 signaling pathway. However, TGF-β1 may promote healing in the early healing period, and in the middle and late healing periods its overexpression can lead to adhesions hyperplasia. Therefore, how to precisely regulate TGF-β1 signaling pathway to function at a particular time has been a challenge for clinicians and research scientists. In recent years, near infrared light triggered release of drug from hydrogel has been successfully developed. It can remotely and accurately control spatial and temporal patterns of drug release, which means if the synthesized TGF-β1 interference plasmid nanoparticles into this smart hydrogel are successfully loaded, it can control the release of plasmid nanoparticles to enhance the therapeutic effect in vivo at a specific time. Therefore, the aim of this project was to prepare TGF-β1 and TGFBR2 interference plasmid nanoparticles hydrogel system, and to detect the effect of remotely controlling the space-time release of plasmid nanoparticles systems from hydrogel and the effect of inhibiting the formation of adhesions in the chicken flexor tendon injury model. We will further explore the epigenetic mechanisms of upregulation of TGFBR2 to find new therapeutic targets. This study will provide new therapeutic approaches and theoretical support for the inhibition of adhesion formation.

屈指肌腱损伤愈合过程中粘连形成，严重影响手功能恢复，目前仍无有效治疗方法。已有研究通过阻断TGF-β1信号通路来抑制粘连形成，但愈合早期TGF-β1可促进愈合，到中后期其过度表达才导致粘连增生。所以如何精确调控TGF-β1信号通路在特定时间发挥功能，使其即可以抑制粘连形成，同时也不影响肌腱愈合成为研究的难点。近年来，近红外响应水凝胶载药系统被成功研制，能以极高的时空精确度远程控制药物释放，这提示我们如果将前期成功合成的TGF-β1干扰质粒纳米球负载于这一智能水凝胶，将可以控制质粒纳米球在体内特定时间释放来增强治疗效果。因此本研究拟制备负载TGF-β1和TGFBR2的干扰质粒纳米球水凝胶系统，并在鸡屈肌腱损伤模型中检测远程控制质粒纳米球时空释放效果及抑制粘连形成效果。同时我们将从表观遗传学角度进一步探讨TGFBR2上调机制以寻找新的治疗靶点。本研究可为抑制粘连形成提供新的治疗方法和理论支持。

屈指肌腱损伤后愈合过程中粘连的形成，导致手功能恢复效果不理想，是手外科领域急需解决的一个难题。已有研究包括我们课题组研究发现在肌腱损伤愈合过程中TGF-β1和TGFBR2表达显著升高，与粘连形成密切相关，为此通过多种方法来阻断TGF-β1信号通路来抑制粘连形成，但由于愈合早期TGF-β1可促进愈合，到中后期其过度表达才导致粘连增生。所以如何精确调控TGF-β1信号通路在特定时间发挥功能，使其即可以抑制粘连形成，同时也不影响肌腱愈合成为研究的难点。近年来，近红外响应水凝胶载药系统被成功研制，能以极高的时空精确度远程控制药物释放，这提示我们如果将前期成功合成的TGF-β1干扰质粒纳米球负载于这一智能水凝胶，将可以控制质粒纳米球在体内特定时间释放来增强治疗效果。本研究通过制备低能近红外响应的载TGF-β1和TGFBR2干扰质粒纳米球水凝胶并检测其相关特征。在细胞水平上检测发现，该水凝胶具有良好的生物相容性，较高的转染能力，能有效抑制TGF-β1和TGFBR2的表达；在鸡屈指肌腱损伤模型上检测这一载基因智能水凝胶能抑制TGF-β1和TGFBR2表达，且能显著抑制肌腱粘连形成，同时不影响肌腱的愈合，最后从表观遗传学角度进一步发现损伤愈合过程中，TGFBR2基因启动子区发生明显的去甲基化，且NF-кB p65能显著增加与去甲基化区域的结合，进而参与TGFBR2上调。这些研究结果提示NF-кB p65可能是抑制粘连形成的潜在靶点。本研究成果可为防治屈指肌腱粘连形成提供新的治疗方法和理论依据。