Synthesis, characterization and properties of carboxymethyl kappa carrageenan

In order to develop a wound healing material possessing anticoagulant activity, antimicrobial activity and moisture absorbability and moisture-retention capacity, carboxymethyl kappa-carrageenan (CMKC) was synthesized by the reaction of kappa-carrageenan with monochloroacetic acid. The products were characterized by FT-IR, C-13 NMR, degree of substitution (DS) and molecular weight. Anticoagulant activity of CMKC was investigated by APTT, IT and PT assays. The results showed that CMKC with a low DS promoted anticoagulant activity in comparison with kappa-carrageenan, but as the DS further increased from 0.42 to 1.09, the activity decreased. Antibacterial activity was evaluated and we found that the introduction of carboxymethyl groups conferred antibacterial activity onto kappa-carrageenan. Results indicated that CMKC exhibited good antimicrobial properties against Escherichia coli and Staphylococcus aureus, and the antibacterial activity of CMKC enhanced as the DS increased. CMKC displayed better moisture-absorption and water-retention ability than kappa-carrageenan and as the DS increased, these properties of CMKC increased. (C) 2011 Elsevier Ltd. All rights reserved.