Cryopreservation of Rat Hepatocytes in a Three-Dimensional Culture Configuration Using a Controlled-

From engineered tissues to transfected cell lines, the long term storage of living biologicals is desirable for a variety of medical, scientific, economic, and regulatory concerns, including transport, the expense of development, repeatability issues, and the point of use. Currently, the best option is cryogenic storage, placing the biomaterials in suspended animation at very low temperatures (−196�C), halting all chemical reactions, limiting genetic drift, and ensuring the maintenance of cell viability and function upon thawing (1 ). Obtaining such an advantageous state, however, can be a difficult achievement. This problem becomes further complicated as we move toward next generation multicomponent products such as engineered skin and cartilage substitutes, composed of multiple cell types oriented in complicated three-dimensional geometries within an extracellular matrix scaffold (2 –4 ).