Han Daewoo, Sherman Shalli, Filocamo Shaun, Steckl Andrew J
Nanoelectronics Laboratory, Department of Electrical Engineering and Computing Systems, University of Cincinnati, Cincinnati, OH 45221, USA.
Biological Sciences and Technology Team (BSTT), Natick Soldier Research, Development and Engineering Center, Natick, MA 01760, USA.
Acta Biomater. 2017 Apr 15;53:242-249. doi: 10.1016/j.actbio.2017.02.029. Epub 2017 Feb 16.
Electrospun membranes encapsulating nisin in the core of multi-layer coaxial fibers, with a hydrophobic PCL intermediate layer and a hygroscopic cellulose acetate sheath, have been demonstrated to provide long-term antimicrobial activity combined with a hygroscopic outer layer. Antimicrobial performance has been evaluated using modified versions of the antimicrobial textile test AATCC 100 and AATCC 147 against Staphylococcus aureus. The AATCC 147 tests indicate that antimicrobial activity persists up to 7days. The quantitative analysis from the AATCC 100 test indicates that tri-layer coaxial ("triaxial") electrospun fiber membranes provide >99.99% bacteria kill (4logkill) for up to five days. This indicates that the nisin-incorporated triaxial fibers have excellent biocidal activities for up to 5days and then provide biostatic activity for 2 or more days. Compared with other types of electrospun membranes, such as core-sheath coaxial ("coaxial") and single homogenous fibers, triaxial fiber membranes provided more robust and more sustained antimicrobial activity. Single fibers with nisin showed relatively weak activity and only for one day. Coaxial fiber membranes exhibited antimicrobial activity for a long period, but their biocidal activity was much weaker than that of triaxial fiber membranes, and only exhibited >99% bacteria kill (2logkill) after 1day of exposure.
The increase in drug resistant pathogens has driven the need for alternative treatments that are effective against resistant bacteria and do not contribute to drug resistance. Nisin is an excellent model bacteriocin for antimicrobials because of its size and mode of action, and has been extensively used as FDA-approved food preservatives without any problematic resistance growth in bacteria during past decades. Nisin-containing fibers have been previously reported using conventional electrospinning but sustained antimicrobial effect has not been obtained. Here, we report the encapsulation of nisin into a multi-layered nanofiber construct using triaxial electrospinning in order to obtain a long-term antimicrobial activity. This will be highly beneficial in many applications, such as protective textiles, food packaging and cancer therapy.
已证明，在多层同轴纤维的核心中封装有乳酸链球菌素的电纺膜，其具有疏水性聚己内酯中间层和吸湿性醋酸纤维素鞘，可提供长期抗菌活性并结合吸湿性外层。已使用抗菌纺织品测试AATCC 100和AATCC 147的修改版本针对金黄色葡萄球菌评估了抗菌性能。AATCC 147测试表明抗菌活性可持续长达7天。AATCC 100测试的定量分析表明，三层同轴（“三轴”）电纺纤维膜在长达五天的时间内可实现>99.99%的细菌杀灭率（4个对数级杀灭）。这表明含乳酸链球菌素的三轴纤维在长达5天的时间内具有出色的杀菌活性，然后在2天或更长时间内提供抑菌活性。与其他类型的电纺膜相比，如核壳同轴（“同轴”）和单一均质纤维，三轴纤维膜提供了更强健、更持久的抗菌活性。含乳酸链球菌素的单纤维显示出相对较弱的活性，且仅持续一天。同轴纤维膜在很长一段时间内都表现出抗菌活性，但其杀菌活性远低于三轴纤维膜，且仅在暴露1天后才表现出>99%的细菌杀灭率（2个对数级杀灭）。
耐药病原体的增加推动了对有效对抗耐药细菌且不会导致耐药性的替代治疗方法的需求。乳酸链球菌素因其大小和作用方式，是一种出色的抗菌模型细菌素，在过去几十年中已被广泛用作FDA批准的食品防腐剂，且细菌未出现任何有问题的耐药性增长。此前曾报道过使用传统电纺技术制备含乳酸链球菌素的纤维，但未获得持续的抗菌效果。在此，我们报告了使用三轴电纺技术将乳酸链球菌素封装到多层纳米纤维结构中，以获得长期抗菌活性。这在许多应用中，如防护纺织品、食品包装和癌症治疗，将具有极大的益处。
