Reproducible subcutaneous transplantation of cell sheets into recipient mice.

Perfecting tissue engineering and cell sheet transplantation is an important step toward realizing regenerative medicine and is a growing area of research. Before being applied to clinical settings, it is important that these approaches are evaluated in vivo. Here we provide a detailed protocol for handling thin cell sheets, for a simple and highly reproducible subcutaneous transplantation of cell sheets into mice, and for the histological examination of regenerated tissues. Various aspects of transplants can be assessed, such as maintenance, differentiation and proliferation. An emphasis is placed on surgical precision and reproducibility. The resulting consistency between surgeries helps minimize artifacts from surgical variation and therefore enables researchers to not only observe and compare the interactions between host tissues but also to compare transplants among different host animals. A single transplantation can be carried out within ∼10 min.