US Patent 10059809 Material and preparation of biocompatible hemostatic water soluble chitosan

A water soluble biocompatible hydrogel having an amino sugar linked to a hydrophilic polymer is disclosed. Linkage of the amino sugar and hydrophilic polymer may be provided by an imine-amine bond between an amine of the amino sugar and a primary amine of the hydrophilic polymer. The linkage between the amino sugar and the hydrophilic polymer may be provided by reacting an amine of the amino sugar and a primary amine of the hydrophilic polymer with a formate ester in an acidic solution. Water soluble biocompatible polymer having an amino sugar linked to a hydrophilic polymer may be cast into films, dried into gauze and/or combined with salt solutions to provide injectable gels.