Perfusability and immunogenicity of implantable pre-vascularized tissues recapitulating features of native capillary network

Vascularization is a key pre-requisite to engineered anatomical scale three dimensional (3-D) constructs to ensure their nutrient and oxygen supply upon implantation. Presently, engineered pre-vascularized 3-D tissues are limited to only micro-scale hydrogels, which meet neither the anatomical scale needs nor the complexity of natural extracellular matrix (ECM) environments. Anatomical scale perfusable constructs are critically needed for translational applications. To overcome this challenge, we previously developed pre-vascularized ECM sheets with long and oriented dense microvascular networks. The present study further evaluated the patency, perfusability and innate immune response toward these pre-vascularized constructs. Macrophage-co-cultured pre-vascularized constructs were evaluated in vitro to confirm micro-vessel patency and perturbations in macrophage metabolism. Subcutaneously implanted pre-vascularized constructs remained viable and formed a functional anastomosis with host vasculature within 3 days of implantation. This completely biological pre-vascularized construct holds great potential as a building block to engineer perfusable anatomical scale tissues. Engineering completely biological, readily implantable, and perfusable pre-vascularized tissue-construct featuring native capillary networks. [Display omitted] •A completely biological and native capillary network-mimicking implantable pre-vascularized constructs were developed with oriented and patent micron-scale vascular networks.•Immunogenicity of engineered microvascular networks were evaluated in vitro and in vivo via macrophage co-culture and subcutaneous implantation in RNU nude rats.•Metabolic perturbation in co-cultured macrophages were evaluated using a novel label-free fluorescence lifetime imaging (FLIM).•Pre-vascularized tissue constructs formed a functional anastomosis and were successfully perfused within 3 days of implantation.