Comparison of Microfat, Nanofat and Extracellular Matrix/Stromal Vascular Fraction Gel for Skin Rejuvenation: Basic Research and Clinical Applications.

BACKGROUND Over the past two decades, fat grafting has been extensively applied in the field of tissue regeneration. OBJECTIVES The authors investigated the therapeutic potential of microfat, nanofat and extracellular matrix/stromal vascular fraction gel (SVF-gel) in skin rejuvenation. METHODS Microfat was harvested by a cannula with multiple 0.8 mm smooth side holes and processed with a fat stirrer to remove fibers. Nanofat and SVF-gel were prepared according to previously reported methods. We evaluated their structure and viability. Then, stromal vascular fraction (SVF) cells from the three types of samples were isolated and characterized, and the cell viability was compared. RESULTS The microstructure of the three samples showed distinct differences. The microfat group showed a diameter of 100 to 120 .0μmunder the microscope and presented abotryoid shape under Calcein-AM/Propidium iodide (AM/PI) staining. Scanning electron microscopy (SEM) analysis showed that the microfat maintained integral histological structure.In the nanofat group, no viable adipocytes and no normal histological structure were observed, with high levels of free lipids.The SVF-gel group showed uniform dispersion of cells with different sizes and parts of the adipose histological structure. Cell count and culture revealed that the number of viable SVF cells decreased distinctly in the nanofat group compared with the microfat group. In contrast, the number of viable SVF cells in the SVF-gel group increased moderately. Clinical applications with microfat showed marked improvements in skin wrinkles. CONCLUSIONS The study showed that the microfat could preserve the integrity of the histological structure and presents the advantages of subcutaneous volumetric restoration and improvement of skin quality in skin rejuvenation compared with the nanofat and SVF-gel.