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

BACKGROUND: Although stromal vascular fraction (SVF) cells and adipose-derived stem cells (ADSCs) have well-defined antiaging effects on skin, their disadvantages including their easy loss due to the lack of extracellular matrix protection and lack of capacity supplementation have limited their clinical application.

OBJECTIVES: To evaluate the effects of microfat, nanofat, and SVF-gel in improving ultraviolet (UV)-induced photoaged skin injury in nude mice.

METHODS: After a photoaging model was successfully established by UVA and UVB irradiation in nude mice, the back of each mouse was divided into 2 regions and randomly injected with 0.5 ml of microfat, nanofat, SVF-gel, and phosphate buffer saline (PBS) by a 27G needle tip under the dermis. The inflammatory infiltration, dermis thickness, hydroxyproline content and ratio of the type Ⅰ and type Ⅲ collagen, elastic fiber morphology, skin cell proliferation，and viability of adipocytes were measured. The overall structure of the skin was also observed by scanning electron microscopy (SEM).

RESULTS: In the microfat group, the grafts survived well, with intact structure and viable adipocytes and little infiltration of inflammatory cells. Microfat promoted skin cell proliferation, collagen content increased and ratio of the type Ⅰ and Ⅲ collagen reversed, and new oxytalan fibers formed, which to some extent improved the photoaging skin. In the nanofat and SVF-gel groups, a large amount of inflammatory cell infiltration and foam cell deposition in the grafts and dermis led to fibrosis and proliferation of skin tissue. Although the skin thickness and collagen content were also increased, these factors did not improve the photoaging skin.

CONCLUSIONS: Microfat has good fat survival, which has favorable and competent effects in improving photoaged skin injury in nude mice by promoting skin tissue regeneration and supplementing the subcutaneous adipose tissue capacity.