Glucan gels

#This application is a filing under 35 USC 371 of International Application No. PCT/GB2011/052358, filed 29 Nov. 2011, which claims priority to GB Application No. 1020191.1, filed 29 Nov. 2010. These prior applications are incorporated herein by reference.

#The present invention relates to a new glucan product, to processes for its manufacture and to uses thereof as a pharmaceutical, incorporated in a medical device, as a nutraceutical, cosmetic product or the like.

#Glucans are a heterogeneous group of glucose polymers found in the cell walls of plants, bacteria, fungi and protozoa. Glucans have a backbone chain and in some cases side chains which, depending of the origin of the glucan, comprise β(1,3), β(1,4) and/or β(1,6)-linked glucosyl units. Depending upon the source and method of isolation, beta-glucans have various degrees of branching and type of linkage in the backbone and side chains. The frequency and type of linkage in the side chains is highly relevant to the molecule's biological activity. Glucans also differ highly in their molecular weight as well as in their tendency for chain aggregation which both are essential features for the efficacy profile of these molecules. Most beta-glucans of fungal and yeast origin are in their native state insoluble in water, but can be made soluble either by acid hydrolysis or by derivatization introducing foreign groups like -phosphate, -sulphate, -amine, -carboxymethyl and so forth to the molecule.

#The invention will now be further described in the following non-limiting Examples and the figures in which:

#FIG. 1 shows storage modulus, G′ (Pa), plotted against temperature for a glucan gel according to the present invention. The data was obtained by small strain oscillatory measurements using a Stresstech HR rheometer and the following temperature scan: 70 to 10° C. at a rate of ⅓° C./min, kept at 10° C. for 2 h and then 10 to 70° C. at a rate of ⅓° C./min. The melting temperature of this gel (gel to sol) is determined to approximately 40 ° C. based on where the increasing temperature curve levels out (G′≈0 Pa).

#FIGS. 2 a) to e) show in vitro stimulation of human mDC with different batches and concentrations of SG (081-5, 252-7, 342-8, 421-4) and different concentrations of SG-LS (421-4 new). The concentration of secreted a) TNFα, b) G-CSF, c) IL-10, d) CXCL-10 and e) IL-12p70 are indicated along the y-axis.

#Preparation of Gel Glucan Product of the Present Invention (SG-LS)

#An aqueous solution of 2% yeast glucan molecules was treated as described below. This aqueous solution was prepared from a particulate glucan preparation by formolysis to selectively remove β-1,6 side chains and subsequent purification and diafiltration to remove particulate matter and low molecular weight components from the formolysis solution. A suitable formolysis step is disclosed in Example 3 of EP 0759089 B1. The particulate glucan was itself prepared from cell walls of Baker's Yeast (S. cerevisiae) by separate extractions with alkali, ethanol and water, each extraction being followed by appropriate drying (spray drying and vacuum drying).

#a. Disruption of Hydrogen Bonds By Addition of Sodium Hydroxide: