Application of multi-needle injector for delivering human adipose stem cells to combat photoaging in nude mice.

To assess the efficacy of human adipose stem cells(ADSCs) in treating photo-aged skin using multi-needle injector versus syringe injection methods. Mice were divided into three groups: blank, model, and experimental. Skin photoaging was induced by eight weeks of UVB irradiation in the model and experimental groups. ADSCs (1 × 10 cells/120µL) were injected into the experimental group mice thrice over a 30-day period, using a syringe on one side and a multi-needle injector on the other side of the nude mice dorsum. Follow-up assessments one month post-injection included high-definition photography for wrinkle and needle mark analysis, histological evaluation of dermal thickness, collagen and elastic fibers. CD31 and Type I collagen levels were analyzed by immunohistochemistry, while MDA and SOD levels were assessed by ELISA assays. Post-UVB irradiation, significant photoaging signs were observed in the mice, including wrinkles and disordered collagen and elastic fibers. ADSCs treatment led to epidermal thinning, dermal collagen thickening, and improved collagen and elastic fiber organization. CD31 and Type I collagen expression increased, while MDA decreased, and SOD significantly increased. No significant differences were found between the injection methods. Multi-needle injector marks disappeared within 24 h, contrasting with syringe marks, and mass formation was reduced compared to syringe injections. ADSCs effectively ameliorate photoaging in mice. Multi-needle injector injections match the efficacy of syringe injections and offer advantages such as precise depth control and reduced mass formation, suggesting its potential as an effective tool for stem cell-based anti-aging treatments.