Characterization of Glycol Chitosan: A Potential Material for Use in Biomedical and Pharmaceutical Applications A Comparison of Fractionation Techniques

摘要

Glycol chitosan, a water soluble chitosan derivative being proposed as a material for pharmaceutical and biomedical engineering applications, was modified to further promote its use in vivo. Initial characterization of the glycol chitosan with !H NMR spectroscopy illustrated the presence of both secondary and tertiary amine groups. Fractionation of glycol chitosan with nitrous acid resulted in a significant reduction in the number average molecular weight, specifically, from 210 to approximately 7-8 kDa, However, the structural integrity of the glycol chitosan was lost following fractionation, as the secondary amine groups were converted to N-nitrosamines, which are potentially carcinogenic. An increase in the pH of the reaction limited their formation, but not entirely; therefore, a second approach to reducing the molecular weight was sought. The free radical degradation, initiated with potassium persulfate, was not as effective at reducing the molecular weight, which ranged from 17 to 20 kDa post fractionation, but did retain the structural integrity of the glycol chitosan.