Cell transplantation has wide-ranging applications in establishing xenograft tumor models, studying in vivo differentiation of stem cells, and repairing tissue for regenerative medicine. Biodegradable microcarriers have long been used to deliver anchorage-dependent cells, and prolonged survival and function of transplanted cells has been demonstrated. However, cells isolated from animal or human populations are generally heterogeneous, and must, therefore, be selectively isolated from a mixed population prior to implantation into another animal. To address this, the authors build upon the original description of the CellRaft® Technology. Biodegradable CellRafts® are micromolded out of poly(lactic-co-glycolic acid) (PLGA), rather than polystyrene, as originally described. Cells plated on the arrays attach to the biodegradable CellRafts® and can be identified, sorted, and implanted into animals. As a proof-of-concept study, Allbritton and colleagues subcutaneously injected mice with biodegradable CellRafts® carrying human pancreatic adenocarcinoma cells to establish a xenograft tumor model and demonstrate the in vivo degradation of the implanted CellRafts®.