The invention relates to a sterilized thermogelling composition comprising a chitosan having N-acetyl-glucosamine units, glucosamine units, and substituted glucosamine units other than the N-acetyl-glucosamine units, said substituted chitosan preferably having a degree of substitution of the glucosamine units ranging from 10 to 50%, expressed as a number of moles of the substituent based on the number of moles of total units, to its preparation and to its applications.
