Absorption and distribution of chitosan in mice after oral administration

Four chitosan samples with different molecular weight Mw and the degree of deacetylation DD (HCS 7.60 × 105 and 85.5%, MCS 3.27 × 104 and 85.2%, COS 0.99 × 103 and 85.7%, WSC 3.91 × 104 and 52.6%) were prepared, and labeled by fluorescein isothiocyanate. These labeled samples were used to investigate the absorption and distribution in mice after oral administration. The results indicated that the absorption and distribution of chitosan was significantly influenced by its Mw and water-solubility. The absorption of chitosan molecules increased with the decrease of the Mw and the increase of the water-solubility. The absorbed chitosan molecules were distributed to all tested organs such as liver, kidney, spleen, thymus, heart and lung. The chitooligomer molecules were easily absorbed and metabolized. The absorbed chitosan molecules from water-soluble WSC in all tested tissues maintained high concentration for a long period. The results suggest that different chitosan may be employed for different functional food.