Long term preservation is crucial as an enabling technology for tissue engineering. Cryopreservation would provide an ideal solution to this need except that ice crystallization in complex multicomponent tissues causes injury to the cells and the extracellular matrix rendering the tissue nonfunctional. Vitreous cryopreservation that stabilizes the biosystem as a glass, thereby avoiding ice crystallization, leads to markedly improved cryopreservation. However, vitrification is not easily achieved in bulk samples relevant to clinical applications because of constraints on attaining sufficiently high cooling and warming rates to preclude ice formation. The ultimate goal of banking natural and engineered tissues using vitrification will be achieved only if adequate methods of controlling ice growth are devised. This study is focused on a novel approach to controlling ice in complex tissues by combining conventional cryoprotective agents with synthetic ice blocker (SIB) molecules and naturally-occurring antifreeze peptides. SIBs are a series of proprietary molecules designed on the basis of molecular-modeling studies to limit ice nucleation and growth. Existing and newly designed SIBs will be applied to the challenge of designing solutions for vitrifying bulk samples without ice damage and showing feasibility for the long-term storage of vascular grafts.
The technology development proposed in this application will enable the emerging tissue engineering industry to make more effective and efficient use of new developments in tissue preservation. Current tissue and cell storage methods have well-recognized technical problems associated with ice formation. A primary goal of Organ Recovery Systems, Inc. (ORS) is development of methods and devices for storage and transportation of biological materials, tissues and organs for both in vitro and in vivo use. Ultimately, the success of both allogeneic transplantation and tissue engineering depends upon the availability of practical product storage and transportation methods. The only methods currently used for unlimited storage and stabilization of cells and tissues involve the application of cryobiology. The potential markets are enormous. Cryopreservation methods, which result in retained viability and function, will be licensed to the tissue engineering industry.
