Glucans
The present invention relates to a glucan having a weight average molar mass of 15,000 to 50,000 g/mol on a single chain basis and a weight average molar mass in aqueous solution on an aggregate basis of 4 to 20×10 5 g/mol and existing in gel form in aqueous solution at a concentration ≥1% at 25° C. and neutral pH and having a melting temperature (gel to sol) of 30 to 44° C. when the glucan is dissolved in water at a concentration of 2%, methods for the production thereof, medical uses thereof, physical supports having the glucan applied thereto or impregnated thereon and in vitro methods of proliferation of skin cells which comprise contacting a population of skin cells with the glucan.
1. A gel glucan product obtainable by
a) heating an aqueous solution of soluble yeast glucan molecules to a temperature of 120° C. to 130° C. and holding the solution at that temperature for 10 to 30 mins; and
b) cooling the glucan solution to a temperature of 35° C. to 50° C., over a time period of less than 80 minutes,
wherein said glucan is present in said gel glucan product at a concentration of 1 to 6%, has a weight average molar mass of 15,000 to 50,000 g/mol on a single chain basis and a weight average molar mass in aqueous solution on an aggregate basis of 4 to 20×10 5 g/mol, and wherein said gel glucan product has a gel to sol melting temperature between 30° C. and 44° C.
2. The gel glucan product of claim 1 , wherein said glucan has a weight average molar mass of 20,000 to 40,000 g/mol on a single chain basis.
3. The gel glucan product of claim 1 , wherein said glucan has a weight average molar mass of 25,000 to 30,000 g/mol on a single chain basis.
4. The gel glucan product of claim 1 , wherein said glucan is in aqueous solution at a concentration of about 2%.
5. The gel glucan product of claim 1 , wherein said glucan is derived from Saccharomyces cerevisiae.
6. The gel glucan product of claim 1 , wherein said glucan is a beta glucan comprising a backbone of β-(1,3)-linked glucosyl residues and side chains comprising 2 or more β-(1,3)-linked glucosyl residues, the sidechains being attached to the backbone via a β-(1,6)-linkage.
7. The gel glucan product of claim 1 , wherein said glucan is essentially free of repetitive β(1,6) linked glucosyl residues.
8. The gel glucan product of claim 1 , wherein said gel glucan product has a gel to sol melting temperature of about 33° C.
9. The gel glucan product of claim 1 , wherein in step a) the glucan is held at the temperature of 120° C. to 130° C. for about 20 minutes.
10. The gel glucan product of claim 1 , wherein in step a) the aqueous solution of glucan molecules is heated to a temperature of 120° C. to 125° C.
11. The gel glucan product of claim 10 , wherein in step a) the glucan is held at the temperature of 120° C. to 125° C. for about 20 minutes.
12. The gel glucan product of claim 1 , wherein the glucan is cooled over a time period of 50 to 60 minutes.
13. The gel glucan product of claim 1 , wherein said method is preceded by a formolysis step wherein a particulate glucan starting material is suspended in formic acid in order to remove β-(1,6) linked glucosyl side chains and to solubilise the particulate glucan.
14. The gel glucan product of claim 13 , wherein the formolysed product is filtered through a mesh of about 0.2 μ.
15. The gel glucan product of claim 1 , which is present in a pharmaceutical composition also comprising one or more pharmaceutically acceptable diluents or carriers.
16. A physical support having applied thereto or impregnated therein the gel glucan product of claim 1 .
17. The physical support of claim 16 , wherein said physical support is selected from the group consisting of a woven, non-woven, knitted, foam or adhesive substrate; a patch, dressing, plaster, bandage, film or gauze.