A rapid and general moulding strategy that uses carbohydrate glass as a sacrificial template for the formation of vascular networks in engineered tissues is reported online this week in Nature Materials. The approach may enable the scaling up of engineered tissue scaffolds that maintain their function at physiological densities, and that may be used as therapeutic replacements.

Without vascular networks that can deliver nutrients and oxygen and remove metabolic byproducts, tissues quickly develop a necrotic core that suppresses their function. But constructing perfusable three-dimensional vascular tissues in the laboratory has only been possible through slow and complex procedures that are usually restricted in the types of materials and cells that can be used.

Using a mixture of glucose and sucrose, and taking advantage of three-dimensional printing, Christopher Chen and colleagues made a network of glass filaments and encased it with a suspension of living cells in their extracellular matrix. After crosslinking the matrix, the researchers dissolved the filaments in cell media. The filaments flowed out of the network leaving behind channels that could be perfused with blood within minutes.

The researchers also demonstrate that the approach is compatible with many types of cells, extracellular matrices and crosslinking strategies, and that it allows for independent control of the network geometry and cell type, both in the lining of the vascular channels and between them.