Bioprintable Blood Vessels

A team from Brigham and Women's Hospital (Massachusetts, USA) has made headway in fabricating blood vessels using a three-dimensional (3D) bioprinting technique.  Ali Khademhosseini and colleagues first used a 3D bioprinter to make an agarose (naturally derived sugar-based molecule) fiber template to serve as the mold for the blood vessels. They then covered the mold with a gelatin-like substance called hydrogel, forming a cast over the mold which was then reinforced via photocrosslinks. The team was then able to construct microchannel networks exhibiting various architectural features. They also successfully embedded these functional and perfusable microchannels inside a wide range of commonly used hydrogels, such as methacrylated gelatin or poly(ethylene glycol)-based hydrogels at different concentrations. Methacrylated gelatin laden with cells, in particular, was used to show how their fabricated vascular networks functioned to improve mass transport, cellular viability and cellular differentiation. Moreover, successful formation of endothelial monolayers within the fabricated channels was achieved.  The study authors submit that: “Overall, our proposed strategy represents an effective technique for vascularization of hydrogel constructs with useful applications in tissue engineering and organs on a chip.”