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The chlorinated hydroxyethyl cellulose (HEC-Cl) was prepared by the chlorinated reaction of hydroxyethyl cellulose (HEC) and thionyl chloride, and dopamine-modified hydroxyethyl cellulose (HEC-DA) was prepared by the reaction of dopamine and HEC-Cl. The nano-silver supported on dopamine-modified cellulose (HEC-DA@AgNPs) was obtained by immersing the HEC-DA in AgNO3 solutions, where silver ions are absorbed and reduced by catechol groups. The X-ray photoelectron spectroscopy spectra of HEC-DA@AgNPs shows that the silver nanoparticles was loaded in the HEC-DA, and the diameter of AgNPs on the surface of HEC-DA is about 20 ± 10 nm. The catalytic activity was detected by the reduction of 4-NP, and it could be accomplished within 3 min with an apparent rate constant of 22.9 × 10−3 s−1. Therefore, the HEC-DA@AgNPs is expected to be a promising catalytic material. [ABSTRACT FROM AUTHOR]

Tannin-immobilized cellulose was prepared by the phenolic reaction of the phenol ring of tannin with the aldehyde group of aldocellulose, where aldocellulose was prepared by the oxidization of cellulose with sodium periodate as oxidizing agent. The method of immobilized tannin is environmentally friendly due to the lack of crosslinking agent. The adsorption properties of cellulose were improved due to the introduction of tannin. The maximum adsorption capacity of the tannin-immobilized cellulose for berberine hydrochloride was 143.66 mg/g. The isothermal adsorption for berberine hydrochloride conformed to the Langmuir model well. The adsorption of tannin-immobilized cellulose for berberine hydrochloride was a weak chemical adsorption, and the adsorption process was exothermic. The adsorption equilibrium was reached within 90 min in the initial concentration 100 mg/L, and the sorption kinetics fitted well to a pseudo-first-order model. Tannin-immobilized cellulose has potential application prospect in the field of the separation and purification of alkaloids. [ABSTRACT FROM AUTHOR]

The composite microspheres based on gelatin (Gel) and chitosan (Cs) loaded with 5-fluorouracil (5-FU) were fabricated using glutaraldehyde (GA) as a crosslinker. Thein-vitrodegradation behaviors of the Gel/Cs microspheres, including the changes of pH value, mass loss and microsphere morphology, were studied. Thein-vitrocytotoxicites of Gel/Cs microspheres loaded and unloaded with 5-FU were carried out with MCF-7 breast cancer cell line. The empty Gel/Cs microspheres showed a smooth surface and were evenly distributed; however, there was much aggregation observed for the microspheres loaded with 5-FU. The degradation results showed that the pH values of both PBS and PBS-lysozyme solutions increased with increasing degradation time but the increase of pH value of PBS-lysozyme solution was quicker than that of PBS solution. The aggregated Gel/Cs microspheres lose their shape and many fibers were found after 21 days in PBS solution; while the Gel/Cs microsphere disappeared in PBS-lysozyme solution. The mass loss of the Gel/Cs microspheres in PBS-lysozyme solution was larger than that of the Gel/Cs in PBS solution. The results indicated that lysozyme can accelerate the degradation of Gel/Cs microspheres. The cytotoxicity results showed that the cell viability decreased with increasing glutaraldehyde content for the empty Gel/Cs microspheres; however, the cell viability increased with increasing glutaraldehyde content for the Gel/Cs microspheres loaded with 5-FU. Therefore, the Gel/Cs microspheres can be offered as drug carrier candidates for long-term applications of anti-cancer drugs. [ABSTRACT FROM AUTHOR]

Physically crosslinked polyvinyl alcohol/collagen composite hydrogels were prepared by a cyclic freezing-drying technique. The biological properties of the hydrogels, including hemolysis, anaphylaxis, pyrogen and acute systemic toxicity tests and implantation in-vivo, were investigated. The hemolysis test suggested that the polyvinyl alcohol/collagen, with a hemolysis index of 1.19%, did not have an obvious hemolysis reaction. There was no toxicosis or death cases observed in the acute systemic toxicity test, and the hydrogel showed no anaphylaxis or pyrogen response. The composite hydrogel showed a good histological compatibility in the in-vivo study. The results indicated that the polyvinyl alcohol/collagen composite hydrogels have promising applications for pharmaceutical and biomedical fields. [ABSTRACT FROM AUTHOR]