Synthesis and Bioactivity of Cellulose Derivatives

Abstract

Cellulose derivatives having carboxyl‐ or carboxymethyl‐ and sulphate groups were synthesized with control of reaction conditions to regulate the distribution of substituents and molecular weights of the products. Sodium cellulose sulphates (NaCS) were synthesized through acetosulphation of cellulose or direct sulphating of cellulose and cellulose‐2.5‐acetate (C2.5A). The properties of the products were controlled by choice of starting materials and reaction parameters like reaction temperature and duration. Cellulose sulphates containing carboxyl groups were prepared through oxidation with 2,2,6,6‐tetramethylpiperidine‐1‐oxyl radical (TEMPO)/NaBr/NaClO in water or through carboxymethylation with chloroacetic acid after alkali treatment with sodium hydroxide. The biological activity of the products was analyzed with a binding assay to fibroblast growth factor (b‐FGF). It was found that NaCS with maximum O‐6‐sulfation and intermediate to high O‐2‐sulfation was able to bind b‐FGF comparable to natural heparin. Products being sulphated and afterwards carboxymethylated at all three positions were also able to bind substantial quantities of b‐FGF.