Physicochemical characterization of irradiated high molar mass chitosan

The present study is aimed to determine the bioburden for assessing the sterilization dose and to identify the influence of the absorbed gamma radiation dose on the molar mass and chemical structure of chitosan. The characterization includes the determination of the intrinsic viscosity, deacetylation degree as well as infrared spectroscopy. The obtained results have shown the occurrence of chain cleavage caused by irradiation. It was revealed by a decrease in the intrinsic viscosities of the polymers. The invariance of the infrared spectra of polymers indicated that chain degradation occurs without significant change of the chemical structure. The results obtained have practical implication in the field of radiation sterilization of chitosan used for microencapsulation of mammalian cells.