Then, on the basis of selection of CPA type and concentration, the procedure should predict an optimal cooling and warming rate based upon: LpCPA, PCPA, cr, and their activation energies. By establishing this order, one is able to work within the cells’ osmotic tolerance limits (which are currently more difficult to modify) and subsequently adjust the cooling and warming rates (which are easily adjustable using current programmable cooling/ warming units).
Application of fundamental cryobiology appears to be species-dependent, and cryopreservation of boar spermatozoa is considerably more challenging and complicated than the cryopreservation of spermatozoa from other species. However, with the knowledge of the osmotic tolerance limits of the cells, their response to CPA addition and removal, and the characterization of the water loss of the cell experienced during cooling and warming, this challenge can become more manageable. Future efforts should focus on engineering methods for expanding the osmotic tolerance limits of boar spermatozoa. Other extenders and their components should be studied to determine their effects on boar sperm permeability and osmotic tolerance. In addition, further investigations should be conducted to determine optimal cooling and warming rates, as well as their interactions, on a CPA-dependent basis. When applied, this information on the fundamental cryobiology of boar spermatozoa would insure minimal volume excursion during cooling and warming, and CPA addition and removal, thereby maximizing post-treatment functional viability.