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Oxidized carboxymethyl cellulose (OCMC) was prepared by an oxidation reaction of carboxymethyl cellulose in the presence of sodium periodate. In situ crosslinked hydrogels were obtained through the crosslinking reaction between the active aldehyde of OCMC and the amino groups of the carboxymethyl chitosan (CMCS). The structure of the hydrogels was characterized by FTIR and scanning electron microscopy. Gelation time test showed that the hydrogel had the shortest gelation time of 24 s. The equilibrium fluid content, which represented the swelling degree, was evaluated and we found that the pH increased from 3.0 to 9.0, the equilibrium fluid content increased, and the highest equilibrium fluid content reached 312.83% as pH = 9.0. The wound healing efficacy of the hydrogel was evaluated in experimental deep second degree burns using a rat model. Results indicated that the wound covered with hydrogel was completely filled with new epithelium within 2 weeks, without any significant adverse reactions. The in situ crosslinked hydrogel fulfilled many critical elements in a wound dressing material. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

To develop a renewable and compatible anticoagulant as potential heparin alternative, carboxymethyl starch sulfate (CMSS) was prepared by the reaction of carboxymethyl starch (CMS) and sulfating reagent [N(SO3Na)3]. The chemical structures of CMS and CMSS were characterized by Fourier transform infrared spectroscopy and 13C nuclear magnetic resonance. The influences of reaction parameters, including the pH of sulfating reagent, the molar ratio of sulfating reagent to CMS, reaction time, and temperature on the degree of substitution of sulfate groups (DS) of CMSS were studied. Meantime, the DS of each CMSS was determined by barium sulfate–glutin nephelometery method. Moreover, the anticoagulant activity of CMSS was investigated by the coagulation assays of activated partial thromboplastin time, thrombin time, and prothrombin time. The results revealed that the anticoagulant activity of CMSS was closely related to the DS value and concentration. The anticoagulant activity was promoted with the increasing of the DS and concentration. The molecular weight (Mw) in measured range had little impact on anticoagulant activity in contract to the DS and concentration. In this article, the CMSS with the DS of 1.91, concentration of 75 μg/mL and the Mw of 2.61 × 104 had the best blood anticoagulant activities. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013