Three-dimensional bioprinting of in vitro tumor organoid and organ-on-a-chip models

In the past decade, organoid and organ-on-a-chip cancer models have rapidly gained attention as alternatives to traditional two-dimensional cell cultures and murine models. However, they are still relatively "low throughput"-meaning that, similar to animal models, relatively low numbers of replicates are used in a given study. Bioprinting offers a solution to this limitation. Bioprinting technology enables the biofabrication of organoid models at increased throughput, furthering the use of organoid/organ-on-a-chip systems in basic science and translational studies. In this article, we describe current bioprinting and biomaterial technologies that generate organoid and organ-on-a-chip platforms, recent deployments of such model systems across tumor types and in the rapidly advancing fields of immune-oncology and personalized medicine, and a look to future directions.