3D bioprinting of an implantable xeno‐free vascularized human skin graft

Abstract

Bioengineered tissues or organs produced using matrix proteins or components derived from xenogeneic sources pose risks of allergic responses, immune rejection, or even autoimmunity. Here, we report successful xeno-free isolation, expansion, and cryopreservation of human endothelial cells, fibroblasts, pericytes and keratinocytes from a single donor. We further demonstrate the bioprinting of a human skin substitute with a dermal layer containing xeno-free cultured human endothelial cells (EC), fibroblasts, and pericytes in a xeno-free bioink containing human collagen type I and fibronectin layered in a biocompatible polyglycolic acid (PGA) mesh and subsequently seeded with xeno-free human keratinocytes to form an epidermal layer. Following implantation of such bilayered skin grafts on the dorsum of immunodeficient mice, keratinocytes form a mature stratified epidermis with rete ridge-like structures. The ECs and pericytes form human EC-lined perfused microvessels within 2 weeks after implantation, preventing graft necrosis, and eliciting further perfusion of the graft by angiogenic host microvessels. In summary, we describe the fabrication of a bioprinted vascularized bilayered skin substitute under completely xeno-free culture conditions demonstrating feasibility of a xeno-free approach to complex tissue engineering.

RGD-Functionalized Hydrogel Supports the Chondrogenic Commitment of Adipose Mesenchymal Stromal Cells

“…These results indicated that all hydrogel properties (both mechanical and biochemical) were favorable to maintain positive hASCs characteristics. Our results are in line with previous studies [ 52 , 53 ], showing different cell types (like immune, epithelial, and stem cells) encapsulated in VG-based hydrogels. The results demonstrated that these hydrogels were interesting matrices able to create a cell-friendly environment.…”

3D Bioprinting and Its Role in a Wound Healing Renaissance

“…PGA is a synthetic polymer that is biocompatible and is widely used in extrusion‐based 3DP. [ 93–95 ] Baltazar et al. 3D printed bioink onto PGA meshes and incorporated human keratinocytes, fibroblasts, pericytes, and endothelial cells in various combinations.…”

“…[ 94 ] Their dermal bioink consisted of fibroblasts, pericytes, and endothelial cells encapsulated within a mixture consisting of human AB serum, human plasma fibronectin, human collagen, and a commercial hydrogel product. [ 94 ] Epidermal bioink contained keratinocytes within a mixture of commercial mediums, ascorbic acid, and human serum‐free KGF. [ 94 ] An initial layer of the dermal bioink was printed, upon which the PGA mesh was placed.…”

“…[ 94 ] Epidermal bioink contained keratinocytes within a mixture of commercial mediums, ascorbic acid, and human serum‐free KGF. [ 94 ] An initial layer of the dermal bioink was printed, upon which the PGA mesh was placed. [ 94 ] Following this, another layer of the dermal bioink was printed.…”

“…[ 94 ] An initial layer of the dermal bioink was printed, upon which the PGA mesh was placed. [ 94 ] Following this, another layer of the dermal bioink was printed. [ 94 ] After several days of culture, the epidermal bioink was printed on top of the construct.…”