Building, Preserving, and Applying Extracellular Culture Integrity Using New Cell Culture Methods and Surfaces

Cultivation of mammalian cells holds promise for generating cell and tissue models and transplants, but the shortcomings of current cell culture methods are limiting such use. In order to provide biological material that can represent cells and tissues of the body in drug development and regenerate organs and systems impaired by disease in the clinic, it is important to recognize that the extracellular integrity, the interphase between the cultureware surface and the cells, and the cell-to-cell contacts are an integral part of the cell culture. One example would be the deposition of type IV collagen, the main structural component of the basement membrane, by human endothelial cells, which can be manipulated by varying the cultureware surface and/or the level of oxidative stress in the culture. Even if culture protocols were optimized to make the cell environment more like the environment in the body, the integrity of the culture would be destroyed during cell harvesting, as matrix molecules are digested by enzymes used for dissociating the cells, and cannot be accumulated from one passage to another. The Thermo Scientific Nunc^TM UpCell^TM Surface enables dissociation of cells from the cultureware upon a simple change in temperature. Being slightly hydrophobic at 37°C, the surface allows cells to attach and grow, but hydrophilic when the temperature is reduced to below 32°C, the surface will bind water and swell, resulting in the release of adherent cells with their underlying matrix molecules. The preservation of matrix molecules enables the harvesting of contiguous cell sheets, which can be grafted onto another cell layer in vivo or in vitro without the use of fibrin glue or sutures. This chapter gives examples of how extracellular culture integrity can be built, preserved, and applied in cell analysis and tissue engineering.