The long term objective of this proposal is the development of cryopreservation methods which cause less interstitial tissue damage than methods currently employed for preservation of heart valves. The underlying hypothesis is that rapid deterioration observed in some patients is due to interstitial ice damage which occurs during cryopreservation and subsequently leads to calcification upon implantation. The Phase I aims are screening two synthetic antifreeze compounds designed by the company in combination with naturally occurring antifreeze peptides, an antifreeze glycoprotein and selected cryoprotectants. First ice formation will be studied and antifreeze/cryoprotectant formulations will be selected based on ice morphology during freezing and thawing. Second, the selected formulations will be tested in vitro for cytotoxicity and cell survival during controlled rate freezing. Lastly, ice formation in porcine heart valves will be studied using minimally toxic formulations which promote cell viability during freezing. The formulations that provide the highest cell viability and least ice formation will be later tested in larger animal allograft models.
NOT AVAILABLE
| Brockbank, Kelvin G M; Song, Ying C (2003) Mechanisms of bioprosthetic heart valve calcification. Transplantation 75:1133-5 |
| Brockbank, K G; Lightfoot, F G; Song, Y C et al. (2000) Interstitial ice formation in cryopreserved homografts: a possible cause of tissue deterioration and calcification in vivo. J Heart Valve Dis 9:200-6 |
