University of California

University of Southwestern Louisiana

Lois M Crowe

John H Crowe

John F Carpenter

Steven C Hand

Fern Tablin

Ann E Oliver

Nelly M Tsvetkova

Willem F Wolkers

Lisa M Hays

Ann F Oliver

Robert E Feeney

A dehydrated composition is provided that includes freeze-dried erythrocytic cells. Alcohol (e.g., sterol or cholesterol) is at least partially removed from erythrocytic cells including erythrocytic membranes. After removal of at least part of the alcohol, the erythrocytic cells have a low phase transition temperature range, an intermediate phase transition temperature range, and a high phase transition temperature range. The erythrocytic cells may be loaded with an oligosaccharide (e.g., trehalose) which preserves biological properties during freeze-drying and rehydration. A process for increasing cooperativity of a phase transition of an erythrocytic cell. A process for preserving and/or increasing the survival of dehydrated erythrocytic cells, including storing dehydrated erythrocytic cells having a residual water content equal to or less than about 0.30 gram of water per gram of dry weight erythrocytic cells.

Erythrocytic cells and method for preserving cells

Leakage from liposomes or biological cells and structural damage, which occur upon cooling through the thermotropic phase transition temperature and upon storage at temperatures below the phase transition temperature are reduced or eliminated by incorporating thermal hysteresis proteins in the liposome or cell structure. Preferred thermal hysteresis proteins are antifreeze proteins and antifreeze glycoproteins from polar fish species, and chromatographic fraction no. 8 of antifreeze glycoproteins has been found to be particularly effective.

Prevention of leakage and phase separation during thermotropic phase

A method of protecting soluble proteins such that their biological activity is preserved after freezing by exposing the protein to an amino acid or trimethylamine-N-oxide and transition metal ion prior to freezing. The protected protein can then be thawed without denaturation or impairment of the protein's biological activity. The protein is preferably exposed to the amino acid or trimethylamine-N-oxide by placing it in a 25-100 mM aqueous solution of organic solute and 1 mM Zn.sup.+2. This method is especially effective in preserving the biological activity of fragile proteins such as the enzyme phosphofructokinase. The present method can be used to preserve pharmaceutically useful proteins in a frozen form for storage and distribution. The treated protein can be thawed and administered directly to a user without removing the cryoprotectant since the amino acid or oxide and trace amounts of many transition metal ions are nontoxic.

Cryogenic protection of phosphofructokinase using amino acids and zinc

A method for preserving liposomes includes freeze-drying liposomes most preferably having an average size of about 50 nm to 100 nm with a disaccharide preserving agent being present both internally (with the encapsulated liposomal contents) and externally. The disaccharide component is in a weight ratio with respect to the lipid component of from at least about 0.1:1 to not greater than about 4:1 and is preferably trehalose. When the lyophilizates are reconstituted by rehydration, the resultant liposomes can retain up to 100% of the originally encapsulated contents.

Method for preserving liposomes

A method of protecting soluble proteins such that their biological activity is preserved after freezing by exposing the protein to a carbohydrate and transition metal ion prior to freezing. The protected protein can then be thawed or lyophilized and rehydrated without denaturation of impairment of the protein's biological activity. The protein is preferably exposed to the carbohydrate by placing it in a 25-100 mM aqueous solution of carbohydrate and 2 mM Z.sup.+2. This method is especially effective in preserving the biological activity of fragile proteins such as the enzyme phosphofructokinase. The present method can be used to preserve pharmaceutically useful proteins in a frozen or freeze-dried form for storage and distribution. The treated protein can be thawed or rehydrated and administered directly to a user without removing the cryoprotectant since the carbohydrates and trace amounts of many transition metal ions are nontoxic.

Growing community of inventors

Davis, CA, United States of America

Lois M Crowe