Tissue-Engineered Soft-Tissue Reconstruction Using Noninvasive Mechanical Preconditioning and a Shelf-Ready Allograft Adipose Matrix.

BACKGROUND: Adipose tissue defects leading to severe functional (disability) and morphologic (disfigurement) morbidity are often treated in plastic surgery with fat grafting, which can be limited by resorption, necrosis, and cyst formation. This study aimed to assess whether adipose scaffolds could provide an environment for in situ autologous fat grafting, and to study whether adipose cell migration and proliferation (adipogenesis) within scaffolds could be enhanced by preliminarily increasing the vascularity (preconditioning) of the surrounding tissue receiving the scaffolds. METHODS: Using an established rodent model of subcutaneous tissue/scaffold grafting, the authors tested the potential of a human-derived, shelf-ready, injectable, decellularized allograft adipose matrix to reconstruct soft-tissue defects when used in combination with noninvasive mechanical (suction-induced) skin preconditioning. RESULTS: Combined use of the allograft adipose matrix and noninvasive skin preconditioning significantly improved long-term volume retention (50 to 80 percent higher at a 12-week follow-up) and histologic quality of reconstructed tissues compared with standard of care (autologous adipose grafts). The components of the allograft adipose matrix supported adipogenesis and angiogenesis. Combining the allograft adipose matrix with living adipose grafts mitigated negative outcomes (lower long-term volume retention, higher presence of cystic-like areas). CONCLUSIONS: This study suggests that the synergistic use of the allograft adipose matrix and noninvasive tissue preconditioning provides an effective solution for improving fat grafting. These strategies can easily be tested in clinical trials and could establish the basis for a novel therapeutic paradigm in reconstructive surgery.

Do Processing Methods Make a Difference in Acellular Dermal Matrix Properties?

BACKGROUND: The use of acellular dermal matrices (ADMs) has become the standard of practice in many reconstructive and aesthetic surgical applications. Different methods used to prepare the allograft tissue for surgical use can alter the ADMs natural properties. Aseptic processing has been shown to retain the natural properties of ADMs more favorably than terminally sterilized ADMs. Terminal sterilization has been historically linked to alteration of biological materials. In vitro work was conducted to compare ADM processing methods. OBJECTIVES: Characterize aseptically processed ADMs and compare cell-matrix interaction characteristics to terminally sterilized ADMs. METHODS: Two aseptically processed ADMs, FlexHD Pliable and BellaDerm, were characterized via histological evaluation, biomechanical integrity, enzymatic degradation, and in vitro cell studies. FlexHD Pliable was compared to Alloderm Ready-to-Use (RTU). RESULTS: Histological evaluation revealed that FlexHD Pliable had a uniform, open structure compared to BellaDerm. Mechanical characterization demonstrated that BellaDerm had higher strength and stiffness compared to FlexHD Pliable, which maintained higher elasticity. Immunohistochemical analysis verified that key matrix proteins remained intact after aseptic processing. Cell studies found that fibroblasts attached more readily, and proliferated faster on FlexHD Pliable compared to BellaDerm. Additionally, fibroblasts infiltrated into FlexHD Pliable from both sides and on the dermal side in BellaDerm and produced an abundance of multi-layered matrix proteins (collagen, fibronectin) when compared to AlloDerm RTU which was sparse. CONCLUSIONS: Aseptically processed FlexHD Pliable and BellaDerm provide a suitable, biocompatible option for tissue repair and regeneration in aesthetic and reconstructive surgical applications.