Characterization of Engineered Scaffolds with Spatial Prevascularized Networks for Bulk Tissue Regeneration.

Despite significant progress in the fabrication of prevascularized networks over the past decade, a number of challenges remain. One of the most relevant issues is the lack of three-dimensional (3D) structures, which limits the clinical applications of the engineered scaffolds. Another problem is the complexity of prevascularized networks in engineered scaffolds, which is still less than that of human tissues, especially in the case of mature and bulk tissues. Thus, there is still the need to develop more flexible methods to better simulate the structure of natural tissues. In this work, we used a versatile sacrificial template method to fabricate bulk scaffolds with spatial prevascularized networks. Soft poly(vinyl alcohol) (PVA) filaments were used to print the sacrificial template, and the receiving platform was a stepped shaft, allowing the sacrificial template to have a complex 3D structure. The obtained template was embedded into gelatin and microbial transglutaminase (mTG). The inner PVA template could be extracted from the enzymatic cross-linking system, and an engineered scaffold with spatial prevascularized networks was obtained. In vitro experiments demonstrated that the fabrication process is biocompatible with cells.