Аннотация:Viability and surface morphology of human erythrocytes upon the interaction with oligochitosan (OCH) having the molecular weight (MW) 6.2-15.4 kDa and a degree of acetylation (DA) 1-2%, and the interaction with N-reacetylated OCH (ROCH) with MW 6.4-14.3 kDa and DA 24-30% were studied in isotonic saline phosphate buffer with pH 7.4. It was shown that OCH caused a high hemolysis and irreversible transformation of the erythrocytes. Thus, OCH having MW 6.2 kDa and DA 1% used at 0.01% concentration induced a high hemolysis of erythrocytes and their viability did not exceed the maximal value of 60%. Among the non-haemolyzed erythrocytes, about 20% of the reversibly and about 20% of the irreversibly transformed erythrocytes were observed in comparison with the control experiments. For the first time, it was shown that ROCHs caused a much lower impact on the cells. Thus, about 82% of the erythrocytes had the a discoid form while 12% of the cells underwent reversible and about 6% irreversible transformations in the presence of ROCH (MW 6.4, DA 24%) used at 0.01% concentration. It was observed that an increase in MW and concentration of chitosan derivatives led to a decrease in the cells viability. It was supposed that the complexation of chitosan derivatives with phosphate counter ions in the buffer might reduce the impact of chitosan derivatives on the viability and surface morphology of erythrocytes due to a reduction in the average zeta potential of chitosan derivative/phosphate complexes from positive to negative values. These results supported the suggestion that reacetylation and reduction in the overall charge of chitosan molecules could improve the compatibility of chitosan derivatives with erythrocytes. This finding opens an opportunity for construction of chitosan derivatives and their complexes compatible with other blood forming elements.
