Human Adipose Allograft Restores Volume Through Host-mediated Tissue Replacement.

BACKGROUND

Advances in adipose tissue technology have led to the development of a commercial human adipose tissue allograft (hATA) for the restoration of adipose volume; hATA retains native adipose architecture, including structurally intact adipocytes, while eliminating immunogenic components to allow allogeneic use. This study evaluates the mechanisms by which hATA restores volume and the fate of donor-derived human deoxyribonucleic acid (DNA) and proteins following in vivo implantation.

METHODS

Tissue structure and adipocyte integrity in hATA were evaluated by histology and free lipid analysis. The absence of extracellular damage-associated molecular patterns was assessed by DNA electrophoresis. In vivo remodeling and persistence of human-derived molecules were evaluated in a 12-week nude mouse model. Grafts were evaluated by visual appearance and weight; histology and immunohistochemistry; and the presence of human cells, adiponectin, and DNA. Systemic distribution was evaluated by human adiponectin detection in mouse serum.

RESULTS

The hATA lacked immunogenic cells and extracellular damage-associated molecular patterns. Following in vivo implantation, hATA was populated by host-derived cells that remodeled and replaced the graft with host tissue. Human DNA was not detectable beyond 4 weeks, and human proteins progressively degraded. No human molecules were detected in systemic circulation.

CONCLUSIONS

Use of hATA provides immediate volume restoration through structurally intact adipocytes with retention maintained by host-mediated tissue regeneration. These findings support the graft replacement theory as the mechanism underlying hATA remodeling in vivo.