Rudra Jai S, Dave Komal, Haynie Donald T
Biomedical Engineering, Bionanosystems Engineering Laboratory, Center for Applied Physics Studies, PO Box 10348, Louisiana Tech University, Ruston, LA 71272, USA.
J Biomater Sci Polym Ed. 2006;17(11):1301-15. doi: 10.1163/156856206778667433.
A multilayer coating (or film) of nanometer-thick layers can be made by sequential adsorption of oppositely charged polyelectrolytes on a solid support. The method is known as layer-by-layer assembly (LBL). No special apparatus is required for LBL and nanofilms can be prepared under mild, physiological conditions. A multilayer nanofilm in which at least one of the constituent species is a polypeptide is a polypeptide multilayer nanofilm. The present work was aimed at assessing whether polypeptide multilayer nanofilms with specific antimicrobial properties could be prepared by incorporation of a known antimicrobial agent in the film structure, in this case the edible protein hen egg white lysozyme (HEWL). The chicken enzyme is widely employed as a human food preservative. An advantage of LBL in this context is that the nanofilm is fabricated directly on the surface of interest, eliminating the need to incorporate the antimicrobial in other packaging materials. Here, nanofilms were made of poly(L-glutamic acid) (PLGA), which is highly negatively charged in the mildly acidic pH range, and HEWL, which has a high net positive charge at acidic pH. We show that PLGA/HEWL nanofilms inhibit growth of the model microbe Microccocus luteus in the surrounding liquid medium. The amount of HEWL released from PLGA/HEWL films depends on the number of HEWL layers and therefore on the total quantity of HEWL in the films. This initial study provides a sketch of the scope for further development of LBL in the area of antimicrobial polypeptide multilayer films. Potential applications of such films include strategies for food preservation and coatings for implant devices.
通过在固体载体上依次吸附带相反电荷的聚电解质，可以制备出具有纳米级厚度层的多层涂层（或薄膜）。该方法被称为层层组装（LBL）。LBL不需要特殊的仪器设备，并且可以在温和的生理条件下制备纳米薄膜。其中至少一种组成成分是多肽的多层纳米薄膜就是多肽多层纳米薄膜。本研究旨在评估通过在薄膜结构中加入一种已知的抗菌剂（在本案例中为可食用蛋白质鸡蛋清溶菌酶（HEWL）），是否能够制备出具有特定抗菌性能的多肽多层纳米薄膜。这种鸡源酶被广泛用作人类食品防腐剂。在这种情况下，LBL的一个优点是纳米薄膜直接在目标表面上制备，无需将抗菌剂添加到其他包装材料中。在这里，纳米薄膜由聚（L-谷氨酸）（PLGA）和HEWL制成，PLGA在微酸性pH范围内带高度负电荷，而HEWL在酸性pH下具有高净正电荷。我们表明，PLGA/HEWL纳米薄膜能够抑制周围液体培养基中模式微生物藤黄微球菌的生长。从PLGA/HEWL薄膜中释放的HEWL量取决于HEWL层数，因此也取决于薄膜中HEWL的总量。这项初步研究勾勒了LBL在抗菌多肽多层薄膜领域进一步发展的前景。此类薄膜的潜在应用包括食品保鲜策略和植入装置涂层。
