Conventional
chitosan hydrogels exhibit an acidic nature and contain unfavorable additives because (i)
chitosan is soluble only in acidic solutions and (ii) toxic chemicals or
proteins of non-human origin that serve as
antigens are necessary for preparing
chitosan hydrogels. These characteristics of the
chitosan hydrogels limit their possibilities as
wound dressings. In this study, a
chitosan-
gluconic acid conjugate is developed, soluble in an aqueous
solution at neutral pH and gellable by freeze-thawing (cryogelation) without using additives. The viability of L929 fibroblasts cultured in the presence of the
chitosan derivative for 24 h was >96%. The degradation rate of the corresponding
chitosan cryogels by
lysozyme was tunable via the derivative concentration in the
gels. The
gels had low cellular adhesiveness. The
gels promoted the accumulation of inflammatory cells such as polymorphonuclear leukocytes, which have the potential to release chemical mediators effective for wound healing, in full-thickness skin
wounds in rats and accelerated the healing of the
wounds. These results demonstrate that
cryogels are promising for
wound care.