Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, USA; Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA.
Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, USA; Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA; Department of Food Science and Technology, SeJong University, Seoul, Republic of Korea.
Carbohydr Polym. 2018 Oct 1;197:623-630. doi: 10.1016/j.carbpol.2018.06.046. Epub 2018 Jun 12.
Chitosan is an abundant and natural polymer derived from chitin, which presents a wide variety of properties, including antimicrobial activity. The raising of antibiotic resistant bacteria has increased the interest in finding alternatives to traditional antibiotics. Many studies have assessed the antimicrobial activity of chitosan itself, but a few have performed comparisons among different chitosan nanoparticle synthesis, which will be of particular interest for further applications. In this study, the effects of two types of cross-linking agents, sodium sulfate vs. tripolyphosphate, along with molecular weight (Mw) of chitosan, low vs. high Mw, and different sonication treatments, time and power, were assessed to determine the optimal conditions to enhance antimicrobial activity against bacterial pathogens. Physiochemical characteristics of the engineered chitosan nanoparticles were determined. It was observed that 20 min sonication time, low Mw of chitosan, Sodium sulfate as cross-linker, and particle size smaller than <300 nm, showed the greatest antimicrobial activity. Chitosan nanoparticles generated at this condition completely killed pathogenic E. coli O157:H7 without raising resistant bacteria, providing great insights into potential use as alternative antimicrobial agents.
壳聚糖是一种丰富的天然聚合物，来源于几丁质，具有多种特性，包括抗菌活性。抗生素耐药菌的出现增加了寻找传统抗生素替代品的兴趣。许多研究已经评估了壳聚糖本身的抗菌活性，但很少有研究比较不同壳聚糖纳米粒子合成方法，这对于进一步的应用将特别有意义。在这项研究中，评估了两种交联剂（硫酸钠与三聚磷酸钠）、壳聚糖的分子量（Mw）（低 Mw 与高 Mw）以及不同的超声处理时间、功率对增强抗菌活性的影响，以确定最佳条件，提高对抗细菌病原体的抗菌活性。对工程壳聚糖纳米粒子的物理化学特性进行了测定。结果表明，20 分钟的超声时间、低分子量的壳聚糖、硫酸钠作为交联剂、粒径小于<300nm，显示出最大的抗菌活性。在这种条件下生成的壳聚糖纳米粒子完全杀死了致病性大肠杆菌 O157:H7，而没有产生耐药菌，这为作为替代抗菌剂的潜在用途提供了重要的见解。
