Cryopreservative compositions and methods
AssigneeRegents of the University of Minnesota
InventorsJohn C. Bischof, Michael L. Etheridge, Jeunghwan Choi
Life of this patent
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Abstract
This disclosure describes compositions and methods related to cryoprotection of biomaterial. Generally, the cryoprotective composition includes a cryoprotective agent and magnetic nanoparticles effective for thawing a cryopreserved specimen comprising biomaterial with minimal biomaterial damage. In some embodiments, the composition is effective for thawing a cryopreserved specimen having a minimum dimension of 0.1 mm. Generally, the method includes obtaining a biomaterial cryopreserved with a cryoprotective composition as summarized above, then subjecting the cryopreserved biomaterial to electromagnetic energy of an intensity sufficient to excite the magnetic nanoparticles and thaw the biomaterial.
Claims22
A method of rewarming a cryopreserved biomaterial, the method comprising:
- applying a radiofrequency (RF) field to a cryopreserved composition in a cryopreserved state, the cryopreserved composition comprising a cryopreserved biomaterial and a cryoprotective composition, wherein the cryopreserved biomaterial is suspended in or perfused with the cryoprotective composition, the cryoprotective composition comprising:
- a cryoprotective agent;
- and
- RF susceptible magnetic nanoparticles comprising iron;
- wherein the magnetic nanoparticles are distributed throughout the cryopreserved composition,
- wherein applying the RF field generates heat at distributed regions throughout the cryopreserved composition by excitation of the distributed magnetic nanoparticles in the RF field, wherein the magnetic nanoparticle distribution is effective for magnetically induced rewarming of the cryopreserved biomaterial that reduces ice crystallization and/or thermal stress throughout the biomaterial during rewarming compared to rewarming by boundary heating or microwave heating,
- wherein the RF field comprises a magnetic field strength of up to about 200 kA/m,
- wherein the concentration of the magnetic nanoparticles in the cryoprotective composition comprises from about 0.01 mg Fe/mL to about 100 mg Fe/mL, and
- wherein the magnetic nanoparticles are superparamagnetic particles having a core diameter of no more than 50 nm and/or ferromagnetic particles having a core diameter of no more than 300 nm.
A method of protecting a cryopreserved biomaterial, the method comprising:
- applying a RF field to a cryopreserved composition comprising a cryoprotective composition and a cryopreserved biomaterial, wherein the cryoprotective composition comprises:
- a cryoprotective agent;
- and
- RF susceptible magnetic nanoparticles comprising iron;
- wherein the magnetic nanoparticles are distributed throughout the cryopreserved composition, wherein applying the RF field generates heat at distributed regions throughout the cryopreserved composition by excitation of the distributed magnetic nanoparticles, wherein the magnetic nanoparticle distribution is effective for magnetically induced rewarming of the cryopreserved biomaterial that reduces ice crystallization and/or thermal stress throughout the biomaterial during rewarming compared to boundary heating or microwave heating when excited with a magnetic field strength of up to about 100 kA/m,
- wherein the magnetic nanoparticles are superparamagnetic particles having a core diameter of no more than 20 nm and/or ferromagnetic particles having a core diameter of no more than 100 nm,
- wherein the concentration of the magnetic nanoparticles in the cryoprotective composition is between about 0.1 mg Fe/mL to about 100 mg Fe/mL,
- wherein the cryopreserved composition has a volumetric specific absorption rate (SARv) of at least 0.1 W/ml.
Dependencies are inferred from the claim text.