Department of Chemistry and Biochemistry, Fairleigh Dickinson University, Teaneck, NJ 07666, USA.
Department of Chemistry and Biochemistry, Fairleigh Dickinson University, Teaneck, NJ 07666, USA.
Int J Biol Macromol. 2023 Apr 1;233:123489. doi: 10.1016/j.ijbiomac.2023.123489. Epub 2023 Feb 2.
This study investigates the effect of addition of tannic acid on nisin encapsulated in chitosan matrices. Composite materials were prepared using a mild, environmentally friendly procedure, ionotropic gelation of chitosan by sodium tripolyphosphate in the presence of nisin (N) at different concentrations. In two parallel sets of preparations, tannic acid (TA) was added at 10:1 and 5:1 N:TA, respectively. The obtained particles were characterized by FTIR, SEM, size, zeta potential, encapsulation efficiency, loading capacity, and ratio of residual free amino groups. The kinetics of nisin release from the particles was studied to assess the role of TA as a potential modulator thereof. Its addition resulted in enhanced release, higher at lower N:TA ratio. An additional benefit was that TA, a strong antioxidant, imparted antioxidant activity to the composites. Antimicrobial turbidimetric tests were performed against one gram-positive bacterium (Staphylococcus aureus) and two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), all relevant for the food, pharmaceutical, and cosmetic industries. All the composites showed synergistic effects against all the bacteria tested. The positive coaction was stronger against the gram-negative species. This is remarkable since nisin by itself has not known activity against them.
本研究考察了添加单宁酸对壳聚糖基质中包裹的乳链菌肽的影响。采用温和、环保的方法制备了复合材料，即壳聚糖在三聚磷酸钠存在下通过离子交联，同时加入不同浓度的乳链菌肽（N）。在两组平行的制备中，分别以 10:1 和 5:1 的 N:TA 添加单宁酸（TA）。通过傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）、粒径、Zeta 电位、包封效率、载药量和残留游离氨基比例对所得颗粒进行了表征。研究了乳链菌肽从颗粒中的释放动力学，以评估 TA 作为潜在调节剂的作用。结果表明，TA 的添加增强了释放效果，且在较低的 N:TA 比下效果更为显著。此外，TA 作为一种强抗氧化剂，赋予了复合材料抗氧化活性。采用浊度法对抗生素测试了一种革兰氏阳性菌（金黄色葡萄球菌）和两种革兰氏阴性菌（大肠杆菌和铜绿假单胞菌），这些细菌都与食品、制药和化妆品行业相关。所有的复合材料对所有测试的细菌都表现出协同作用。阳性协同作用对革兰氏阴性菌更强。这是值得注意的，因为乳链菌肽本身对它们没有已知的活性。
