Preparation And Properties Of Carboxymethyl Chitosan Derivatives

Carboxymethyl chitosan is a kind of important water soluble derivatives.Because of its good biological activity, many scholars have studied the preparation ofcarboxymethyl chitosan and its derivatives in some areas in recent years, especially inthe areas of medicine, environmental protection, cosmetics and food, etc. This paperhas conjugated collagen peptides to the quaternized carboxymethyl chitosan, andgrafted carboxymethyl chitosan with chondroitin sulfate and RGD peptides,respectively. The peptides conjugated with carboxymethyl chitosan and its derivativescould effectively promote the growth of fibroblasts and cell adhesion, the introductionof collagen peptide also improved the antioxidant activity of carboxymethly chitosanand moisture absorption and retention abilities, which could help to avoid futhertissue damage caused by free radical reaction in body surface trauma. Because ofthese materials have good biocompatibility, and could promote the wound healing,shorten the healing time, so they have laid a foundation for the development of newwound dressing. The material of chondroitin sulfate grafted carboxymethyl chitosancould effectively promote the growth of osteoblasts, and endow carboxymethylchitosan with anticoagulant activity, which laid a foundation for the development ofnew bone materials. In the paper, the main research contents and results are asfollows:(1) The quaternized carboxymethyl chitosan (QCMC) were prepared withcarboxymethyl chitosan and water soluble3-chlorine-2-hydroxypropyl trimethylammonium chloride. Then use EDC and NHS as crosslinking agent to preparedQCMC-COP in the water phase. The reaction conditions of QCMC-COP wereoptimized. The optimal conditions were found to be as follows: the mass ratio ofcollagen peptides to QCMC was6.0, the reaction temperature was40℃; the reactiontime was16h. The results of H2O2scavenging effect of QCMC-COP showed thatwith the increase of the DS and concentration, the H2O2scavenging effect increased.With the decrease of the Mw, the H2O2scavenging effect increased firstly, thendecreased, and the best Mw was2.23×10-4. The results of cell viability of fibroblastssuggested that QCMC-COP efficiently promoted the proliferation of fibroblast. Withthe increase of the DS and concentration of QCMC-COP, the cell viability firstly increased and then decreased. The results of cell adhesion of fibroblasts showed thatthe introduction of collagen into quaternized carboxymethyl chitosan couldsignificantly improve the adhesion effect of carboxymethyl chitosan, and the adhesionrate was increased with the increase of the DS and concentration. And the DS andconcentration are positive correlation with the adhesion of fibroblast.(2) Using the EDC and NHS as crosslinking agent to conjugated thecarboxymehtyl chitosan with chondroitin sulfate (CMC-CS). The reaction conditionsof CMC-CS were optimized. The optimal conditions were found to be as follows: themass ratio of chondroitin sulfate to carboxymethyl chitosan was4.0. the reactiontemperature was35℃, the reaction time was24h. The results of anticoagulantexperiment showed that the value of APTT, PT and TT have increased with theincrease of the DS and concentration of the samples, the enhancement of APTT ismost obvious. And the changes of molecular weight have also influenced the APTT,PT and TT. The results of cell viability of osteoblast suggested that CMC-CS couldefficiently promote the proliferation and growth of osteoblast. With the increase of theDS of CMC-CS, the cell viability increased, which is positive correlation with theproliferation of osteoblast. However, with the increase of the concentration of thesamples, the cell viability increased firstly, and then decreased.(3) The carboxymethyl chitosan-GRGDY peptides (CMC-GRGDY) wereprepared by using the EDC and NHS as crosslinking agent. The reaction conditions ofCMC-GRGDY were optimized. The optimal conditions were found to be as follows:the mass ratio of carboxymethyl chitosan to GRGDY was10.0. the reactiontemperature was25℃, the reaction time was48h. The results of cell viability offibroblasts suggested that CMC-GRGDY efficiently promoted the proliferation offibroblast. The cell viability increased with the increase of the DS and concentrationof CMC-GRGDY. And the DS and concentration are positive correlation with theadhesion of fibroblast. The results of cell adhesion of fibroblasts showed that theintroduction of GRGDY peptides into carboxymethyl chitosan could significantlyimprove the adhesion effect of carboxymethyl chitosan, and the adhesion rate wasincreased with the increase of the DS and concentration. And the DS andconcentration are also positive correlation with the adhesion of fibroblast.