Innovative Mechanical Processing of Adipose Tissue: A Comparative Evaluation of Microfat and Concentrated Micronized Fat for Superficial Fat Grafting

Background: Superficial autologous fat grafting is widely used for facial rejuvenation and regenerative treatments, yet its retention rate remains unpredictable. Enhancing the concentration of adipose-derived stem cells (ASCs) has been shown to improve graft retention. Mechanical fat processing techniques can reduce fat granules size for superficial injection as well as elevate the concentration of ASCs.

Objectives: We introduced a novel mechanical fat processing method to convert macrofat into concentrated micronized fat (CMF), which can generate small fat particles and increase the concentration of ASCs. The microstructure, cell composition, and in vivo evaluation of microfat and CMF were compared.

Methods: Adipose tissue was harvested from patients undergoing liposuction. Microfat was obtained using a multiperforated cannula with multiple 1.0-mm smooth side holes, while CMF was prepared with a spinning sharp blade to create smaller particles. Cell counting, viability assays, flow cytometry, ELISA, and in vivo studies were conducted to evaluate the processed fat.

Results: Both CMF and microfat were suitable for superficial fat grafting with 26-gauge needles. Scanning electron microscopy and whole-mounting stain showed that the CMF maintained an integral histological structure. Cell count and flow cytometry tests revealed that the number of ASCs increased significantly in the CMF group compared with the microfat group. In vivo studies demonstrated higher fat retention rates in the CMF group, accompanied by reduced fibrosis and inflammation observed.

Conclusions: The CMF method significantly improves fat graft survival. This innovative approach provides a viable option for improving the outcomes of superficial fat grafting, offering better structural preservation compared to traditional microfat methods.

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