scholarly journals Electrophoretically deposited high molecular weight chitosan/bioactive glass composite coatings on WE43 magnesium alloy

Author(s):  
Agnieszka Witecka ◽  
Svenja Valet ◽  
Michał Basista ◽  
Aldo Roberto Boccaccini
Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 591
Author(s):  
Bożena Grimling ◽  
Bożena Karolewicz ◽  
Urszula Nawrot ◽  
Katarzyna Włodarczyk ◽  
Agata Górniak

Chitosans represent a group of multifunctional drug excipients. Here, we aimed to estimate the impact of high-molecular weight chitosan on the physicochemical properties of clotrimazole–chitosan solid mixtures (CL–CH), prepared by grinding and kneading methods. We characterised these formulas by infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffractometry, and performed in vitro clotrimazole dissolution tests. Additionally, we examined the antifungal activity of clotrimazole–chitosan mixtures against clinical Candida isolates under neutral and acid conditions. The synergistic effect of clotrimazole and chitosan S combinations was observed in tests carried out at pH 4 on Candida glabrata strains. The inhibition of C. glabrata growth reached at least 90%, regardless of the drug/excipient weight ratio, and even at half of the minimal inhibitory concentrations of clotrimazole. Our results demonstrate that clotrimazole and high-molecular weight chitosan could be an effective combination in a topical antifungal formulation, as chitosan acts synergistically with clotrimazole against non-albicans candida strains.


Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1078
Author(s):  
Hang Zhang ◽  
Zhipeng Ma ◽  
Yunpeng Min ◽  
Huiru Wang ◽  
Ru Zhang ◽  
...  

Several kinds of composite materials with phosphotungstic acid (PTA) as the catalyst were prepared with activated carbon as support, and their structures were characterized. According to the Box–Behnken central combination principle, the mathematical model of the heterogeneous system is established. Based on the single-factor experiments, the reaction temperature, the reaction time, the amount of hydrogen peroxide and the loading capacity of PTA were selected as the influencing factors to study the catalyzed oxidation of hydrogen peroxide and degradation of high molecular weight chitosan. The results of IR showed that the catalyst had a Keggin structure. The results of the mercury intrusion test showed that the pore structure of the supported PTA catalyst did not change significantly, and with the increase of PTA loading, the porosity and pore volume decreased regularly, which indicated that PTA molecules had been absorbed and filled into the pore of activated carbon. The results of Response Surface Design (RSD) showed that the optimum reaction conditions of supported PTA catalysts for oxidative degradation of high molecular weight chitosan by hydrogen peroxide were as follows: reaction temperature was 70 ℃, reaction time was 3.0 h, the ratio of hydrogen peroxide to chitosan was 2.4 and the catalyst loading was 30%. Under these conditions, the yield and molecular weight of water-soluble chitosan were 62.8% and 1290 Da, respectively. The supported PTA catalyst maintained high catalytic activity after three reuses, which indicated that the supported PTA catalyst had excellent catalytic activity and stable performance compared with the PTA catalyst.


2020 ◽  
Vol 165 ◽  
pp. 804-821 ◽  
Author(s):  
Florencia Solana Buosi ◽  
Agustina Alaimo ◽  
Mariana Carolina Di Santo ◽  
Fernanda Elías ◽  
Guadalupe García Liñares ◽  
...  

2016 ◽  
Vol 32 ◽  
pp. 79-85 ◽  
Author(s):  
Anderson Fiamingo ◽  
Jorge Augusto de Moura Delezuk ◽  
Stéphane Trombotto ◽  
Laurent David ◽  
Sergio Paulo Campana-Filho

HortScience ◽  
2005 ◽  
Vol 40 (5) ◽  
pp. 1333-1335 ◽  
Author(s):  
Young-Sang Lee ◽  
Yong-Ho Kim ◽  
Sung-Bae Kim

To study the effects of chitosan on the productivity and nutritional quality of soybean (Glycine max L.) sprouts, soybean seeds were soaked in solutions containing 1,000 ppm chitosan of low (<10 kDa), medium (50 to 100 kDa), or high (>1,000 kDa) molecular weight, and the respiration, growth, and vitamin C content of the sprouts were subsequently evaluated. Sprouts treated with high molecular weight chitosan exhibited a significant increase in respiration, 5%, within 1 day of treatment. Chitosan effectively increased the growth of the sprouts: sprouts treated with high molecular weight chitosan showed increases of 3%, 1%, 3%, 1%, and 12% in the total length, hypocotyl length, root length, hypocotyl thickness, and fresh weight, respectively, as compared to a control. The growth-improving effects of chitosan were proportional to the molecular weight of the molecule used in the treatment. Chitosan treatment did not result in any significant reduction in vitamin C content or postharvest chlorophyll formation, traits that determine the nutritional and marketing values of soybean sprouts. All these results suggest that soaking soybean seeds in a solution of chitosan, especially of high molecular weight, may effectively enhance the productivity of soybean sprouts without adverse effects on the nutritional and postharvest characteristics.


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