Differences in the requirements for cryopreservation of porcine aortic smooth muscle and endothelial cells

One of the basic requirements for the production of tissue-engineered const ructs is an effective means of storing both the constructs and the cells th at will be used to make them. This paper reports on the cryopreservation of porcine aortic smooth muscle and endothelial cells intended for the produc tion of model vascular constructs. We first determined the cell volume, non osmotic volume, and the permeability parameters for water and the cryoprote ctant dimethyl sulfoxide (Me2SO) in these cells at 2-4 degrees and 22 degre esC. The following results were obtained: [GRAPHICS] Using a cell culture assay, both cell types were shown to tolerate threefol d changes in cell volume, in either direction, without significant injury. Although these data suggested that single-step methods for the introduction and removal of 10% w/w Me2SO should be effective, an additional mannitol d ilution step was adopted in order to reduce the time required for removal o f the Me2SO. Following cooling at 0.3, 1, or 10 degreesC/min and storage at less than -160 degreesC, the survival of porcine aortic smooth muscle cell suspensions, measured by a cell culture assay, was inversely related to co oling rate; at 0.3 degreesC/min, recovery was >80%. The survival rate for a ortic endothelial cells was directly related to cooling rate over the range tested and was >80% at 10 degreesC/min.