脂肪血管基质组分在放射性皮肤损伤微环境中的转归及临床意义

Conversion of stromal vascular fraction in the microenvironment of radiation⁃induced skin injuries and its clinical implications

目的研究脂肪血管基质组分(SVF)在放射性皮肤损伤微环境中的转归以指导临床应用。方法将C57BL/6N小鼠按随机数表法分为4组:空白对照组、阴性对照组、急性损伤组、慢性损伤组,每组25只。将空白对照组、急性损伤组、慢性损伤组小鼠以15 Gy X射线进行背部局部照射,随后对阴性对照组、急性损伤组、慢性损伤组小鼠局部注射来源于B6/G⁃R小鼠的SVF。通过荧光示踪、活体成像观察SVF注射后1、3、7、14、21 d的存活情况。根据动物实验结果优化临床SVF注射方案,针对不同患者的创面情况以不同频次进行SVF局部注射,并观察疗效。结果急性损伤组、慢性损伤组、阴性对照组在SVF注射后的第14天均可在组织切片中观察到局部组织中的SVF。在注射后1、3、7 d,SVF的荧光信号强度依次为阴性对照组>急性损伤组>慢性损伤组;注射后14 d,SVF的荧光信号强度依次为急性损伤组>阴性对照组>慢性损伤组;注射后21 d,各组SVF荧光信号强度极低。与阴性对照组相比,急性损伤组仅在注射后14 d差异具有统计学意义(t=4.11,P<0.05),慢性损伤组在注射后1、3、7、14 d,差异均具有统计学意义(t=3.88~5.74,P<0.05);急性损伤组的SVF荧光信号强度在第3、7、14、21天均显著高于慢性损伤组(t=4.73~8.38,P<0.05)。阴性对照组、急性损伤组、慢性损伤组的SVF半衰期分别为6.336、6.014、2.163 d。临床试验中在传统手术方案基础上应用SVF移植,显示SVF有明确的促进创面修复作用,且移植越早越有利于创面愈合。结论SVF在急、慢性皮肤辐照损伤微环境中转归不同,对临床应用中SVF的用药时机和注射频次具有临床指导作用。

Objective To investigate the conversion of stromal vascular fraction(SVF)in the microenvironment of radiation⁃induced skin injuries to provide guidance for clinical applications.Methods Based on a random number table,C57BL/6N mice were categorized into four groups:the blank control,negative control,acute injury,and chronic injury groups,with each group containing 25 mice.The backs of mice in the blank control,acute injury,and chronic injury groups were exposed to 15 Gy X⁃ray irradiation.Then,the mice in the negative control,acute injury,and chronic injury groups were injected subcutaneously with the SVF derived from B6/G⁃R mice.The survival of these mice was observed 1,3,7,14,and 21 d after the injection through fluorescence tracing and in vivo imaging.Accordingly,the clinical SVF injection regimens were optimized based on the experimental result of mice.Finally,local SVF injection was performed on different frequencies for patients in different wound conditions,with the efficacy being observed.Results The fluorescence of SVF was observed from the tissue slices of the acute injury,chronic injury,and negative control groups 14 d post⁃injection.The result showed that the fluorescence intensity of SVF 1,3,and 7 d post⁃injection was in the order of the negative control group>the acute injury group>the chronic injury group.The acute injury group ranked at the top and the chronic injury group remained at the bottom 14 d after the injection.The fluorescence of SVF in each group was barely detected 21 d after the injection.Compared to the negative control group,the acute injury group exhibited statistical differences only 14 d post⁃injection(t=4.11,P<0.05),while the chronic injury group displayed statistical differences 1,3,7,and 14 d after the injection(t=3.88-5.74,P<0.05).Furthermore,the acute injury group exhibited significantly higher fluorescence intensity of SVF than the chronic injury group(t=4.73-8.38,P<0.05).The half⁃life of SVF for the negative control,acute injury,and chronic injury groups was 6.336,6.014,and 2.163 d,respectively.As indicated by the application of SVF transplantation based on traditional surgical protocols in the clinical trial,SVF can significantly promote wound repair,with earlier SVF transplantation being more beneficial for wound healing.Conclusions The conversion of SVF differs in the microenvironments of acute and chronic radiation⁃induced skin injuries.This can serve as an essential guide for the administration timing and injection frequency of SVF in clinical applications.