Al-Obaidy Saba S M, Greenway Gillian M, Paunov Vesselin N
Department of Chemistry and Biochemistry, University of Hull, Hull HU6 7RX, UK.
Department of Chemistry, College of Science, University of Babylon, Hilla 51001, Iraq.
Pharmaceutics. 2021 Sep 2;13(9):1389. doi: 10.3390/pharmaceutics13091389.
We report on an active nanocarrier for chlorhexidine (CHX) based on sterically stabilized shellac nanoparticles (NPs) with dual surface functionalization, which greatly enhances the antimicrobial action of CHX. The fabrication process for the CHX nanocarrier is based on pH-induced co-precipitation of CHX-DG from an aqueous solution of ammonium shellac and Poloxamer 407 (P407), which serves as a steric stabilizing agent. This is followed by further surface modification with octadecyl trimethyl ammonium bromide (ODTAB) through a solvent change to yield cationic surface functionality. In this study, we assessed the encapsulation efficiency and release kinetics of the novel nanocarrier for CHX. We further examined the antimicrobial effects of the CHX nanocarriers and their individual components in order to gain better insight into how they work, to improve their design and to explore the impacts of their dual functionalization. The antimicrobial actions of CHX loaded in shellac NPs were examined on three different proxy microorganisms: a Gram-negative bacterium (), a yeast () and a microalgae (). The antimicrobial actions of free CHX and CHX-loaded shellac NPs were compared over the same CHX concentration range. We found that the non-coated shellac NPs loaded with CHX showed inferior action compared with free CHX due to their negative surface charge; however, the ODTAB-coated, CHX-loaded shellac NPs strongly amplified the antimicrobial action of the CHX for the tested microorganisms. The enhancement of the CHX antimicrobial action was thought to be due to the increased electrostatic adhesion between the cationic surface of the ODTAB-coated, CHX-loaded shellac NPs and the anionic surface of the cell walls of the microorganisms, ensuring direct delivery of CHX with a high concentration locally on the cell membrane. The novel CHX nanocarriers with enhanced antimicrobial action may potentially find applications in dentistry for the development of more efficient formulations against conditions such as gingivitis, periodontitis and other oral infections, as well as enabling formulations to have lower CHX concentrations.
我们报道了一种基于具有双重表面功能化的空间稳定紫胶纳米颗粒（NPs）的洗必泰（CHX）活性纳米载体，它极大地增强了CHX的抗菌作用。CHX纳米载体的制备过程基于pH诱导的从紫胶铵水溶液和泊洛沙姆407（P407，用作空间稳定剂）中共同沉淀CHX-DG。随后通过溶剂变化用十八烷基三甲基溴化铵（ODTAB）进行进一步的表面改性，以产生阳离子表面功能。在本研究中，我们评估了新型CHX纳米载体的包封效率和释放动力学。我们进一步研究了CHX纳米载体及其各个组分的抗菌效果，以便更好地了解它们的作用方式，改进其设计并探索其双重功能化的影响。在三种不同的替代微生物上研究了负载在紫胶NPs中的CHX的抗菌作用：一种革兰氏阴性细菌（）、一种酵母（）和一种微藻（）。在相同的CHX浓度范围内比较了游离CHX和负载CHX的紫胶NPs的抗菌作用。我们发现，由于其负表面电荷，负载CHX的未包被紫胶NPs与游离CHX相比表现出较差的作用；然而，ODTAB包被的、负载CHX的紫胶NPs强烈增强了CHX对测试微生物的抗菌作用。CHX抗菌作用的增强被认为是由于ODTAB包被的、负载CHX的紫胶NPs的阳离子表面与微生物细胞壁的阴离子表面之间静电粘附增加，确保了CHX以高浓度直接局部递送至细胞膜上。具有增强抗菌作用的新型CHX纳米载体可能在牙科领域找到应用，用于开发针对牙龈炎、牙周炎和其他口腔感染等病症的更有效制剂，以及使制剂具有更低的CHX浓度。
