Antibacterial activity of textile fibers containing poly(ethylene oxide-b-lactic acid) nanoparticles with incorporated essential oils

ABSTRACT In this study was evaluated the antibacterial activity of textile fibers containing poly (ethylene oxide-b-lactic acid) nanoparticles with incorporated essential oils. The developed system demonstrated antibacterial activity against Staphylococcus aureus, suggesting its potential use as antibacterial agent. Diblock copolymers based on a fixed PEO block (5kDa) and two different PLA segments (4.5 or 10kDa) were used. The morphology, encapsulation efficiency, blending interaction of essential oils (including lavender, tea tree, thyme, cloves, cedar and lemon grass) and polymer and the release kinetics of the active agent in the nanoparticles. The hydrodynamic radius of the nanoparticles determined by light scattering was affected by the size of the poly(lactic acid) block. The in vitro release suggests that the polymeric barrier is able to control the oil release. Antibacterial activity was more effective in textiles with randomly arranged fibers. In agreement with studies from the literature, nanoparticles obtained from copolymers with lower PLA molar mass favored the release of the essential oil mixture. The incorporation process of the essential oils in the textile fibers proved to be efficient, suggesting viability regarding the use of this system in the antibacterial control. The developed systems offer a new strategy for controlled release with antibacterial activity and suggesting a potential application in the footwear industry.

摘要 本研究评估了负载有精油的聚(环氧乙烷-b-乳酸)（poly(ethylene oxide-b-lactic acid)）纳米颗粒的纺织纤维的抗菌活性。所开发的体系对金黄色葡萄球菌（Staphylococcus aureus）展现出抗菌活性，表明其具备作为抗菌剂的应用潜力。本研究采用了基于固定分子量聚环氧乙烷（polyethylene oxide, PEO）嵌段（5 kDa）与两种不同分子量聚乳酸（poly(lactic acid), PLA）嵌段（4.5 kDa或10 kDa）的二嵌段共聚物。对该体系的形貌、包封效率、精油与聚合物的共混相互作用（所涉精油包括薰衣草油、茶树油、百里香油、丁香油、雪松油及柠檬草油），以及纳米颗粒中活性成分的释放动力学进行了表征。经光散射法测得的纳米颗粒流体力学半径，受聚乳酸嵌段的分子量影响显著。体外释放实验结果显示，该聚合物屏障能够实现精油释放的可控调节。纤维随机排布的纺织制品展现出更优异的抗菌效果。与现有文献报道的研究结果相符，由较低分子量聚乳酸嵌段共聚物制备得到的纳米颗粒，更利于精油混合体系的释放。精油在纺织纤维中的负载工艺被证实具有较高效率，提示该体系用于抗菌调控具备实际应用可行性。所开发的这类体系为兼具抗菌活性的控释材料提供了全新的研发策略，同时在制鞋工业领域具备潜在应用前景。