| 摘要 |
1364896 Preservation of cells and tissues OVITRON RESEARCH CORP 8 Dec 1971 [14 Dec 1970] 57048/71 Heading A2D A method of storing cell and cell-like biological substances in an isotonic, inert and compatible liquid medium comprises precompressing the biological substance and medium to a pressure above atmospheric at a rate sufficiently low to avoid damaging pressure transients and at a temperature above the freezing point thereof, the precompression pressure being dependent upon a predetermined lower temperature to be attained in the method, reducing the temperature of the biological substance and medium to said lower temperature while maintaining their volume constant, the lower temperature being above that which would permit freezing of said biological substance and medium at the generated pressure and at or below the normal freezing temperature of the medium and biological substance at atmospheric pressure, maintaining the biological substance and medium at the lower temperature for a time sufficient to permit them to achieve temperature equilibrium and decompressing the biological substance and medium at the lower temperature by an amount sufficient to permit uniform freezing of the biological substance. Following the freezing step, the biological substance and medium may be lowered to a cryogenic temperature and stored thereat. The biological substance and medium may be confined in a plastic bag, immersed in a pressure-transmitting medium. Alternatively, the biological substance may be wrapped in a gauze saturated with the medium. The precompression may range up to 12,000 p.s.i. and the lower temperature before the freezing step may be between 0‹C and -22‹C. A suitable apparatus for carrying out the method of the invention is shown in Fig. 2 and consists of a non-dilatable vessel 14 which comprises a cup-shaped member 16 co-operating with a threaded cover 18. The biological substance and medium e.g. a cornea 10 immersed in Buckley's solution 12, are added to the container and the cover 18 threaded into position, the desired precompression pressure being obtained by turning the cover through a sufficient number of turns. The precompression may take place whilst vessel 14 is in a temperature control bath (Fig. 3, not shown). The vessel may remain in this bath operating at different temperatures, or in other baths maintained at different temperatures, for the further method steps of attaining the lower temperature and attaining a cryogenic temperature. |
