纳米脂肪来源囊泡促进增生性瘢痕愈合的研究OA

Objective Investigating the effect of nanofat-derived extracellular vesicles(NF-EVs)on hypertrophic scar healing in rabbit ears.Methods Adipose tissue from rabbit scapular regions was mechanically emulsified 60 times,followed by low-speed centrifugation(1 000 rpm,10 min)to remove cellular components.The supernatant and middle layer were then subjected to high-speed centrifugation(14 000 rpm,30 min)to obtain NF-EVs.Nanofat-derived extracellular vesicles(NF-EVs)were characterized using transmission electron microscopy and nanoparticle tracking analysis.A rabbit ear hypertrophic scar model was established,and the scars were randomly divided into three groups:NF-EVs group,triamcinolone acetonide group,and blank control group.Digital photographs of scars and tissue samples were collected on the 30th and 90th days respectively.Scar healing was comprehensively evaluated by measuring scar area,Vancouver Scar Scale(VSS)scores,combined with HE staining and COL Ⅰ immunofluorescence staining.Results The successfully isolated NF-EVs exhibited uniform size(approximately 100 nm in diameter)and displayed a typical double-membrane spherical structure under transmission electron microscopy.After 90 days of treatment,the scar area in the NF-EVs group(10.04±1.42)mm2 was significantly smaller than that in the blank control group(18.83±2.32)mm2,and the difference was statistically significant(P＜0.05).Compared with the triamcinolone acetonide group(10.51±2.13)mm2,the difference was not statistically significant(P＞0.05).The VSS score of the NF-EVs group was lower than that of the blank control group and the triamcinolone acetonide group(P＜0.05).Hematoxylin-eosin(HE)staining revealed that the NF-EVs group had significantly reduced scar thickness with tightly arranged and orderly collagen fibers,whereas the blank control group showed loosely arranged and disordered collagen with a pink reticular pattern.Immunofluorescence assay confirmed that the local tissue expression of COL Ⅰ was significantly decreased in the NF-EVs group.Conclusion NF-EVs can effectively promote the healing and outcome of hypertrophic scars in rabbit ears.