Biofabrication and Characterization of Vascularizing PEG-Norbornene Microgels

Establishing a robust, functional microvascular network remains a critical challenge for both the revascularization of damaged or diseased tissues and the development of engineered biological materials. Vascularizing microgels may aid in efforts to develop complex, multiphasic tissues by providing discrete, vascularized tissue modules that can be distributed throughout engineered constructs to vascularize large volumes. Here, we fabricated poly(ethylene glycol)-norbornene (PEGNB) microgels containing endothelial and stromal cells via flow-focusing microfluidic droplet generation. When embedded in bulk fibrin hydrogels, these cell-laden microgels initiated the formation and development of robust microvascular networks. Furthermore, extended preculture of cell-laden PEGNB microgels enabled the formation of vessel-like structures supported by basement membrane within the matrix without aggregation. Our findings highlight the suitability of PEG-based matrices for the development of vascularizing microgels capable of forming well-distributed, robust microvascular networks.