Decellularized skin/adipose tissue flap matrix for engineering vascularized composite soft tissue flaps

Abstract

Using a perfusion decellularization protocol, we developed a decellularized skin/adipose tissue flap (DSAF) comprising extracellular matrix (ECM) and intact vasculature. Our DSAF had a dominant vascular pedicle, microcirculatory vascularity, and a sensory nerve network and retained three-dimensional (3D) nanofibrous structures well. DSAF, which was composed of collagen and laminin with well-preserved growth factors (e.g., vascular endothelial growth factor, basic fibroblast growth factor), was successfully repopulated with human adipose-derived stem cells (hASCs) and human umbilical vein endothelial cells (HUVECs), which integrated with DSAF and formed 3D aggregates and vessel-like structures in vitro. We used microsurgery techniques to re-anastomose the recellularized DSAF into nude rats. In vivo, the engineered flap construct underwent neovascularization and constructive remodeling, which was characterized by the predominant infiltration of M2 macrophages and significant adipose tissue formation at 3 months postoperatively. Our results indicate that DSAF co-cultured with hASCs and HUVECs is a promising platform for vascularized soft tissue flap engineering. This platform is not limited by the flap size, as the entire construct can be immediately perfused by the recellularized vascular network following simple re-integration into the host using conventional microsurgical techniques.

Macrophages significantly enhance wound healing in a vascularized skin model

“…Other reports describe the infiltration of macrophages in vivo following the implantation of tissue engineered substitutes. For example, decellularized skin/adipose tissue flaps were used to create vascular‐like structures in vitro by co‐culturing HUVECs and adipose‐derived stem cells, followed by the formation of neovasculature and macrophage infiltration in vivo . Similarly, an Integra® dermal substitute for in vivo applications led to macrophage infiltration 14 days after transplantation .…”

“…For example, decellularized skin/adipose tissue flaps were used to create vascular-like structures in vitro by co-culturing HUVECs and adipose-derived stem cells, followed by the formation of neovasculature and macrophage infiltration in vivo. 38 Similarly, an Integra ® dermal substitute for in vivo applications led to macrophage infiltration 14 days after transplantation. 39 Macrophages have primarily been used to monitor the compatibility of tissue engineered constructs, for example, in pre-vascularized and control skin models transplanted into immunocompromised rats 40,41 and sericin-based tissue engineered skin models.…”

Progress in developing decellularized bioscaffolds for enhancing skin construction

“…Hence, the decellularization of skin flaps is essential. 48 Vascularized skin flaps were seeded with adipose-derived stem cells and then anastomosed with the recipient region of wound defects in a nude rat model. 2(E,F)] with an average size of 5 × 3.5 cm 2 using the perfusion method.…”

“…110 Surfactants, the most common decellularized agents, disarranges the phospholipid cell membrane to lysis cells. 48 SD is another ionic surfactant that can solubilize the cell membrane. Decellularization with SDS has met the standard requirements of complete cell removal and elimination of at least 90% of genetic material in several types of tissues and organs, whereas high concentration of SDS damages the structural and signaling proteins.…”

Decellularized extracellular matrices for tissue engineering applications

“…DECM scaffolds improve cell growth, migration, differentiation and can positively influence tissue repair and remodeling [3][4][5][6][7]. DECM from a variety of tissues such as skeletal muscle [8][9][10], brain [11,12], urinary bladder [2,5,13], small intestinal submucosa [14][15][16], liver [4,[17][18][19], skin/adipose tissue [20][21][22], blood vessels [23][24][25], heart valves [26,27] and tendons [28] have been used for tissue engineering applications.…”