Influence of physico-chemical properties of chitin and chitosan on complement activation

To recognize the complement activation by chitin and chitosan, various phys ico-chemical aspects were studied. Complement activation was determined by change of plasma C3 concentration using single radial immunodiffusion metho d. Results were as follows: in samples with homogeneous acetylation (oDAC), C3 concentration was decreased with the increase in the degree of acetylat ion of oDAC. In oDACs 50 and 42 (water soluble materials), however, C3 was not decreased. In samples with heterogeneous acetylation or deacetylation s amples (eDAC), all samples showed C3 activation even in eDAC 53 (solid mate rial) and have almost same activity on complement activation. C3 activation was not seen in low molecular weight materials including D-glucosamine. Th e important factors inducing complement activation by chitosan-based mucopo lysaccharide should be solids. The samples with heterogeneous acetylation ( eDACs) had a stable ability on complement activation than with homogeneous acetylation (oDACs). (C) 2000 Elsevier Science Ltd. All rights reserved.