Preclinical Optimization of a shelf-ready, human-derived, decellularized Allograft Adipose Matrix.

Autologous adipose tissue grafting is a popular strategy for soft tissue reconstruction; yet its clinical outcomes are often suboptimal. Lack of metabolic and architectural support at recipient sites affects the capacity of cellularized autologous grafts to survive after transplantation. Allograft adipose matrices (AAMs) are composed of the extracellular matrices of adipose tissue. They can provide critical bio-physical cues and create a supportive microenvironment for autologous graft survival. Using murine models, we have optimized the in vivo use of an injectable AAM obtained from human cadaveric tissue and processed to remove lipid and cellular components. We hypothesized that the AAM could assist recipient site preparation before autologous adipose tissue grafting and -alone or combined with other treatments- improve surgical outcomes. The AAM scaffolds retained volume (measured as cross-sectional area at histology) over time and showed a higher local angiogenesis. Preconditioning of AAM recipient sites using intermittent external volume expansion (EVE) further increased their vascularity and promoted adipogenesis. Low density AAM combined with autologous adipose tissue grafts best assisted angiogenesis and tissue survival. These studies demonstrate that the AAM contributes to recipient site preparation before or in combination with autologous adipose tissue grafting by increasing vascularity and by creating an adipogenic microenvironment. This patient-ready scaffold could help improve outcomes in soft tissues reconstructive surgery.