Compositions are disclosed herein comprising at least (a) a derivative of an alpha-
glucan, wherein (i) at least about 40% of the glycosidic linkages of the alpha-
glucan are alpha-1,6 linkages, and (ii) the alpha-
glucan has a
degree of substitution (DoS) of about 0.001 to about 3.0 with at least one positively charged
organic group (optionally in
ether linkage); and (b) an insoluble alpha-glucan, wherein at least about 50% of the glycosidic linkages of the insoluble alpha-glucan are alpha-1,3 glycosidic linkages, and the weight-average
degree of polymerization (DPw) of the insoluble alpha-glucan is at least 10. The insoluble alpha-glucan can enhance the degree to which the alpha-glucan derivative deposits onto a
fiber-containing material / article such as fabric, for example. Methods are further disclosed for preparing compositions comprising an alpha-glucan
ether derivative, as well as various applications of using these compositions, such as for controlling microbes on fabric surfaces.