Injection Of Autologous Adipose Tissue Research Articles

Bleomycin-induced Scleroderma in Nude Mice can be Reversed by Injection of Adipose Tissue: Evidence for a Novel Therapeutic Intervention in Systemic Sclerosis

Objective: Systemic sclerosis is an autoimmune disease characterised by uncontrolled fibrosis and vascular insufficiency of the skin and internal organs, without efficient treatments. Subcutaneous adipose transplants have been shown to exert trophic effects on surrounding tissue. We aimed to determine the effects of human adipose tissue in a murine model of sclerotic skin. Methods: Scleroderma was induced in 48 nude mice by daily subcutaneous injection of bleomycin during four weeks. Immediately after the final bleomycin injection, human subcutaneous adipose tissue was implanted into the subcutaneous space of mice using either the Coleman method or the micro-injection method. Epidermal and dermal thicknesses were assessed on skin biopsy specimens six weeks after fat implantation. Capillary density was assessed using immunohistochemistry with an endothelial-specific marker (CD31). Results: Bleomycin increased dermal thickness (p<0.01), collagen network, and density of elastic fibers. Adipose tissue implantation reduced dermal thickness by 10% (p<0.01) with the Coleman method and by 14% (p<0.001) with the micro-injection method. Delivery of adipose tissue by the micro-injection method led to significantly greater neovascularization than the Coleman method (p<0.001). Conclusion: Implantation of human adipose tissue resulted in significant improvement of both fibrosis and peripheral vascular sufficiency in this mouse model of sclerotic skin. Use of a micro-injection method was associated with superior outcome. We postulate that this positive effect is likely due to the activity of the stromal vascular fraction found within adipose tissue. Thus, injection of autologous adipose tissue may be a promising novel therapy for patients with hand or perioral functional impairment.

Histopathologic Evaluation of Adipose Autografts in a Rabbit Ear Model

Injection of autologous adipose tissue removed via liposuction has been used clinically for facial contouring, the aging face, furrows, facial atrophy, acne scars, nasolabial folds, chin, and various other surgical defects. Survival rates for autografts of fat have been quoted anywhere from 30% to 80%. Our study uses a reproducible rabbit animal model for autotransplantation of adipose tissue and examines the histopathologic changes that occur to the graft over time. Autogenous subcutaneous fat was removed from a dorsal scapular donor site, treated to stimulate cannula damage as in liposuction, then reinjected at the base of the ear. Histologic examination of the grafts were made at 5, 10, 15, 20, 40, and 100 days after transplantation. Hematoxylin-eosin sections were graded on degree of fibrosis present (0 to 4+), viable fat (1 to 10), degree of inflammation (0 to 4+), and neovascularization (+ or -). Viability of fat decreased from 8.5 to 10 at 5 days to 2 viability at 40 days. Acute inflammation peaked at 10 days, followed by the chronic inflammatory response with macrophages and multinucleated giant cells scavenging the dying fat graft. Neovascularization began at 5 days, peaked at 10 days, and remained constant thereafter only at the edge of the graft. Microcysts appeared at 15 days and increased in number in proportion to the decrease in viable fat. In summary, the temporal histologic events are progressive fibrosis; decreased amount of viable fat; inflammation beginning with a neutrophilic response, later a macrophage and giant cell response; and neovascularization at the periphery of the graft insufficient to maintain graft viability.(ABSTRACT TRUNCATED AT 250 WORDS)