Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University (UNESP), 14800-903 Araraquara, São Paulo, Brazil.
Department of Drugs and Medicines, School of Pharmaceutical Sciences, São Paulo State University (UNESP), 14800-903 Araraquara, São Paulo, Brazil.
Molecules. 2018 Feb 22;23(2):473. doi: 10.3390/molecules23020473.
Chitosan (CH) is a biopolymer that exhibits a number of interesting properties such as anti-inflammatory and antibacterial activity and is also a promising platform for the incorporation of photosensitizing agents. This study aimed to evaluate the efficacy of antimicrobial activity of chitosan hydrogel formulation alone and in combination with the methylene blue (MB) associated with antimicrobial photodynamic therapy (aPDT) against planktonic and biofilm phase of . Suspensions were sensitized with 12.5, 25.0, 37.5, 50.0 μg/mL of MB for 10 min and biofilms to 75, 100 and 150 μg/mL for 30 min then exposed to red light (660 nm) at 90 J/cm² and 150 J/cm² respectively. After treatments, survival fractions were calculated by counting the number of colony-forming units. The lethal effect of aPDT associated with CH hydrogel in planktonic phase was achieved with 12.5 µg/mL MB and 1.9 log biofilm reduction using 75 µg/mL MB. Rheological studies showed that formulations exhibited pseudoplastic non-Newtonian behavior without thixotropy. Bioadhesion test evidenced that the formulations are highly adhesive to skin and the incorporation of MB did not influence the bioadhesive force of the formulations.
壳聚糖（CH）是一种具有多种有趣特性的生物聚合物，具有抗炎和抗菌活性，也是掺入光敏剂的有前途的平台。本研究旨在评估壳聚糖水凝胶制剂单独以及与亚甲蓝（MB）联合用于抗菌光动力疗法（aPDT）的抗微生物活性，以对抗浮游和生物膜相的 。悬浮液用 12.5、25.0、37.5、50.0 μg/mL 的 MB 敏化 10 分钟，生物膜用 75、100 和 150 μg/mL 敏化 30 分钟，然后分别用 660nm 红光照射 90 J/cm² 和 150 J/cm²。处理后，通过计数菌落形成单位来计算存活分数。在浮游相下，CH 水凝胶与 aPDT 联合的致死作用在 12.5 µg/mL MB 时实现，在 75 µg/mL MB 时实现 1.9 对数的生物膜减少。流变学研究表明，制剂表现出假塑性非牛顿行为，无触变性。生物粘附试验表明，制剂对皮肤具有高度粘附性，并且 MB 的掺入不会影响制剂的生物粘附力。
