Mechanical micronization of lipoaspirates for treatment of bleomycin-induced scleroderma in nude mice

Background Scleroderma is a chronic autoimmune disease that causes hardening of the skin. Adipose tissue is used as a regenerative treatment for scleroderma, and mechanical micronization of adipose tissue can concentrate stem cells, improving its therapeutic efficacy. Stromal vascular fraction gel (SVF gel) is produced by subjecting lipoaspirates to a series of mechanical processes. The present study aimed to assess the therapeutic effect of SVF gel on dermal scleroderma. Methods Scleroderma was induced in nude mice by daily subcutaneous injections of bleomycin (BLM) for 4 weeks. SVF gel, cell-enriched lipoaspirates (CAL), or Coleman fat (CF) (0.1 mL) was injected subcutaneously into local sclerosis lesions. Histological analyses, TUNEL assay, and qRT-PCR were conducted 4 weeks post-transplantation. Results SVF gel, CAL, and CV decreased dermal thickness in the scleroderma model (P < 0.05), and sclerosis was significantly decreased in the SVF gel and CAL groups. SVF gel and CAL decreased macrophage infiltration, pro-inflammatory cytokine levels, and fibrosis in transferred fat and/or skin lesions (P < 0.05). This revealed anti-inflammatory and anti-fibrotic effects of adipose-derived stem cells (ASCs) therapy in scleroderma (P < 0.05). SVF gel exhibited the most potent anti-inflammatory and anti-fibrotic effects among treatment groups (P < 0.05). Conclusion SVF gel and CAL significantly reversed dermal sclerosis, and were more effective than CF. The SVF gel group exhibited the lowest inflammation both in transferred fat and in skin lesions, and also the lowest fibrosis among the three groups. This study suggested that SVF gel was a more suitable adipose-based therapy for topical treatment of scleroderma patients.