PDF(Pubmed)
Abstract：
Periodontal disease is triggered by surface bacterial biofilms where bacteria are less susceptible to antibiotic treatment. The development of liposome-based delivery mechanisms for the therapeutic use of antimicrobial peptides is an attractive alternative in this regard. The cationic antimicrobial peptide LL-37 (human cathelicidin) is well-known to exert antibacterial activity against P orphyromonas gingivalis, a keystone oral pathogen. However, the antibacterial activity of the 16-amino acid fragment (LL17-32) of LL-37, is unknown. In addition, there are still gaps in studies using liposomal formulations as delivery vehicles of antibacterial peptides against this pathogen. This study was designed to examine the influence of the different types of liposomal formulations to associate and deliver LL17-32 to act against P. gingivalis. Chitosans of varying Mw and degree of acetylation (DA) were adsorbed at the surface of soya lecithin (SL) liposomes. Their bulk (average hydrodynamic size, ζ-potential and membrane fluidity) and ultrastructural (d-spacing, half-bilayer thickness and the water layer thickness) biophysical properties were investigated by a panel of techniques (DLS, SAXS, M3-PALS, fluorescence spectroscopy and TEM imaging). Their association efficiency, in vitro release, stability, and efficacy in killing the periodontal pathogen P. gingivalis were also investigated. All liposomal systems possessed spherical morphologies and good shelf-life stabilities. Under physiological conditions, chitosan formulations with a high DA demonstrated enhanced stability in comparison to low DA-chitosan formulations. Chitosans and LL17-32 both decreased SL-liposomal membrane fluidity. LL17-32 exhibited a high degree of association with SL-liposomes without in vitro release. In biological studies, free LL17-32 or chitosans alone, demonstrated microbicidal activity against P. gingivalis, however this was attenuated when LL17-32 was loaded onto the SL-liposome delivery system, presumably due to the restrained release of the peptide. A property that could be harnessed in future studies (e.g., oral mucoadhesive slow-release formulations).
摘要：
牙周病是由表面细菌生物膜引发的，其中细菌对抗生素治疗较不敏感。在这方面,开发用于抗微生物肽的治疗用途的基于脂质体的递送机制是有吸引力的替代方案。众所周知，阳离子抗菌肽LL-37（人cathelicidin）对牙龈卟啉单胞菌具有抗菌活性，主要的口腔病原体。然而,LL-37的16-氨基酸片段(LL17-32)的抗菌活性是未知的。此外,使用脂质体制剂作为抗这种病原体的抗菌肽的递送载体的研究仍然存在空白。本研究旨在检查不同类型的脂质体制剂结合和递送LL17-32以对抗牙龈卟啉单胞菌的影响。不同Mw和乙酰化程度（DA）的壳聚糖吸附在大豆卵磷脂（SL）脂质体的表面。它们的体积(平均流体动力学尺寸，ζ电位和膜流动性)和超微结构(d间距，通过一组技术(DLS，SAXS,M3-PALS,荧光光谱和TEM成像)。它们的关联效率，体外释放，稳定性,和杀死牙周病原体牙龈卟啉单胞菌的功效也被研究。所有脂质体系统都具有球形形态和良好的保质期稳定性。在生理条件下,与低DA-壳聚糖制剂相比,具有高DA的壳聚糖制剂表现出增强的稳定性。壳聚糖和LL17-32均降低SL-脂质体膜的流动性。LL17-32表现出与SL-脂质体的高度缔合而没有体外释放。在生物学研究中,免费的LL17-32或单独的壳聚糖，证明了对牙龈卟啉单胞菌的杀微生物活性，然而，当LL17-32加载到SL脂质体递送系统上时，可能是由于肽的限制释放。可以在未来研究中利用的属性(例如，口腔粘膜粘附缓释制剂)。
