Development of lauroyl sulfated chitosan for enhancing hemocompatibility of chitosan

Chitosan (CS) has received much attention as a functional biopolymer especially in pharmaceutical applications, but has serious limitations owing to its poor hemo-compatibility property. Present paper focuses on the chemical modification of CS in order to enhance hemocompatibility. Amphiphilic derivative (lauroyl sulfated chitosan, ISCS) was prepared by the inclusion of sulfo group (hydrophilic) and lauroyl group (hydrophobic) to CS backbone and particles were prepared by an ionic-gellation approach. Modification was confirmed by FTIR, NMR and zeta potential measurements and the microparticles were evaluated for its particle size, swelling properties and thermal behaviour. Blood compatibility studies like hemolysis, RBC, WBC, platelet aggregation studies, blood clotting time, protein adsorption and C3 protein depletion assay were carried out for these polymers using standard techniques and cytotoxicity studies were performed to understand its applicability. Negatively charged (-6.06 mV) LSCS submicroparticles (886 nm) were prepared in this study. Blood compatibility studies demonstrated that the amphiphilic modification improved the hemocompatibility of CS. RBC aggregation and hemolysis induced by CS were significantly reduced by this modification. Further amphiphilic modification was effective in reducing the protein adsorption on CS. LSCS derivatives were found to be non-toxic in L929 cell lines. From these studies, it appears that LSCS is a hemocompatible version of CS. (C) 2011 Elsevier B.V. All rights reserved.