超声联合4HPR微泡载体治疗瘢痕疙瘩的实验研究

Hyperplastic scar and keloid are the results of local excessive repaire after injured, but no therapy with obvious effect has been found out yet. 4HPR is a novel all-trans retinoic acid derivative which can induce tumor cell apoptosis. In our prophase research, 4HPR can inhibit the proliferation of fibroblasts derived keloid and the synthesis of III Collagen and Hyaluronic Acid. But the molecular mechanism should be more deeply researched. The changes of matrix hardness in scar tissue microenvironment not only related to fibroblast proliferation, apoptosis and differentiation, but also directly affect drug diffusion and absorption. As an energy-transfer substance, Ultrasound can focus on specific position. 4HPR is not only the contrast agent, but also the carrier of drug and gene. In order to definite the role of 4HPR in Pathogenesis of keloid, apoptotic regulators and its theoretical framework induced by 4HPR will be observed. In addition, the safety threshold and optimal parameters of microbubble will be determined. Taken together, this study not only take into account of the methodology of ultrasound combined with 4HPR in therapy of keloid, but also provide the stable theoretical basis and experimental verification for its using in the future.

增生性瘢痕和瘢痕疙瘩是创伤后局部过度修复的结果，尚无特效的治疗方法。4HPR是新的全反式维甲酸类衍生物，诱导肿瘤细胞凋亡。申请者在前期研究观察到4HPR抑制瘢痕疙瘩成纤维细胞（FB）的增殖，减少培养液中Ⅲ型胶原和透明质酸的合成，但是其分子机制有待于深入研究。瘢痕组织微环境基质硬度的改变不尽对FB的增值、凋亡和分化有关，同时直接影响治疗药物的扩散和吸收。超声波作为能量传递物质可聚焦于体内的特定部位，含有气体的微泡即可作为医学超声显像的造影剂，又可作为药物或基因的输送载体。因此本课题拟进一步检测4HPR刺激下瘢痕疙瘩FB增殖和凋亡指标、调控因子及信号级联网络，研究4HPR抑制瘢痕疙瘩形成的分子机制；在此基础上，确定超声微泡应用时的安全阈值以及优化参数；并自制4HPR纳米级载药微泡，探讨超声联合载药微泡介导4HPR治疗瘢痕疙瘩的价值和新方法，为今后的临床应用打下坚实的理论基础和实验依据。

瘢痕疙瘩是皮肤损伤愈合过程中，胶原合成代谢机能失去正常的约束控制，持续处于亢进状态，以致胶原纤维过度增生的结果。瘢痕疙瘩生长行为有类似肿瘤的特性，表现为超出原病损界限的持续性增生，并渐向周围正常皮肤组织侵犯。目前国内外的研究尚未能很好的揭示瘢痕疙瘩呈浸润性过度生长的机制。即使针对瘢痕疙瘩的治疗方法多种多样，但临床治疗效果都达不到预期的目的，迫切需要研究出新的治疗方法解决这一医学难题。4-羟苯基维胺(4HPR)是新的全反式维甲酸类衍生物，诱导肿瘤细胞凋亡。申请人在前期研究中已发现4HPR可抑制瘢痕疙瘩成纤维细胞（FB）的增殖，减少培养液中Ⅲ型胶原和透明质酸的合成。但因瘢痕疙瘩组织微环境基质硬度的改变不仅对FB的增值、凋亡和分化有关，同时直接影响治疗药物的扩散和吸收，因此达不到良好的临床疗效。所以本课题采用整合方式开发并制备4HPR纳米级微泡后联合超声探讨了对瘢痕疙瘩的疗效及其机制，并通过制备瘢痕疙瘩裸鼠模型，探索超声联合载药微泡这一介入治疗瘢痕疙瘩新方法的疗效，通过实验阐明了4HPR可抑制FB的增殖和诱导细胞凋亡，证实了超声联合4-HPR纳米级载药微泡治疗瘢痕疙瘩的有效性，并为今后瘢痕疙瘩的临床治疗提供了坚实的理论基础和实验依据。