Patent ID: 7521433

Claim:
A gene carrier composed of a complex in which a single-stranded nucleic acid is bound to a double-stranded β-1,3-glucan wherein the β-1,3-glucan has at least one 1,6-glucopyranoside branch per repeating unit of polysaccharide and is selected from schizophyllan, lentinan, grifolan, and scleroglucan, and wherein at least some of 1,6-glucopyranoside branches are chemically modified to be functionalized with nucleic acid-binding functional groups which are cationic functional groups formed by reaction of the polysaccharide with chain or cyclic compounds containing at least one primary or secondary amino group, wherein the chemical modification is carried out by periodate-oxidizing the 1,6-glucopyranoside branches and then reductive-aminating the periodated 1,6-glucopyranoside branches to impart the nucleic acid binding functional group thereto, and wherein the 1,6-glucopyranoside branch which has been functionalized with the nucleic acid-binding groups is expressed by the following general formula (1): wherein the two X's are the cationic functional groups and are identical or different.