Nanofat Increases Dermis Thickness and Neovascularization in Photoaged Nude Mouse Skin

To investigate the effects of nanofat injection into photoaged nude mouse skin on dermis thickness, neovascularization, and cell proliferation. Adipose-derived stem cells (ADSCs) and nanofat were prepared from human liposuction aspirates. The photoaged skin model was created using ultraviolet B (UVB) radiation onto BALB/c nude mice. A total of 24 mice were used in this study; 6 mice without treatment (natural aging) served as controls, while 18 mice were irradiated under the UVB lamp and treated with PBS (200 mu l per injection area), ADSCs (1 x 10(6)/200 mu l ADSCs per injection area), or nanofat (200 mu l per injection area) on the dorsal skin. Four weeks after injection, skin specimens were collected. The skin texture of each group was evaluated by general observation. Histological analyses were performed to analyze skin structure, dermis thickness, collagen fiber arrangement, capillary density, and cell proliferation. Four weeks after injection, no obvious differences were observed between the PBS group, ADSCs group, and nanofat group by skin gross observation. From the histological analyses, the ADSCs group and the nanofat group showed obviously thicker dermis than the PBS group (P < 0.05). More capillaries were observed in skin using anti-CD31 staining in the ADSCs and Nanofat groups than was observed in the PBS group (P < 0.05). No significant differences in the average dermis proliferation index were observed between groups by anti-Ki-67 staining. However, an increased epidermal proliferation index was observed in the ADSCs and Nanofat groups, compared to that in the PBS group (P < 0.05). Nanofat increased dermis thickness and neovascularization in photoaged skin. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.