"Mechanical Vibration-Extracted Stromal Vascular Fraction Improves Volume Retention after Autologous Fat Grafting".

BACKGROUND The stromal vascular fraction (SVF) can improve volume retention after fat grafting, but the optimal SVF extraction method remains controversial. This study investigated the effect of mechanical vibration on SVF activity and explored the efficacy of vibration as a new extraction method compared to centrifugation, enzyme digestion and nanoemulsion methods. METHODS Twenty-four rabbits were divided into three groups, and adipose tissue was harvested from the scapular region of each rabbit. In the first group, SVF was extracted from adipose tissue by vibration with different frequencies and durations. Cell counts and colony formation were assessed to determine the optimal vibration parameters. In the second group, SVF was extracted by the four methods, and the cell counts, proliferation and adipogenic capabilities were observed in vitro. In the third group, adipose tissue mixed with SVF extracted with the four methods was grafted into rabbit ears. Volume retention and histological changes were evaluated over 24 weeks. RESULTS SVF activity was not influenced by low-frequency (≤45 Hz) and short-duration (≤20 min) vibrations. Vibration at 30 Hz for 15 min was most efficient for SVF extraction. In vitro, SVF extracted by vibration showed advantages for cell viability. In vivo, the vibration group showed a more normal tissue morphology and a higher retention rate (60.68 ± 7.07%) than the enzyme digestion (31.88 ± 4.99%), centrifugation (43.76 ± 4.32%) and nanoemulsion groups (21.79 ± 3.57%) (P<0.05). CONCLUSIONS Vibration at 30 Hz for 15 min is recommended as a novel nonenzymatic method to extract SVF with high activity.