Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel.
Fraunhofer IGB, Stuttgart, Germany.
J Control Release. 2016 May 10;229:163-171. doi: 10.1016/j.jconrel.2016.03.025. Epub 2016 Mar 21.
Cationic antimicrobial peptides (AMPs) are part of the innate immunity, and act against a wide variety of pathogenic microorganisms by perturbation of the microorganism's plasma membrane. Although attractive for clinical applications, these agents suffer from limited stability and activity in vivo, as well as non-specific interaction with host biological membranes, leading to cytotoxic adverse effects. We hypothesized that encapsulation of AMPs within liposomes could result in reduced cytotoxicity, and with enhanced stability as well as bioactivity against herpes simplex virus 1 (HSV-1). We formulated nano-sized liposomal formulations of LL-37 and indolicidin, and their physicochemical properties, cellular uptake, in vitro cytotoxicity and antiviral efficacy have been determined. Lower cytotoxicity of LL-37 liposomes was found in comparison to indolicidin liposomes attributed to the superior physicochemical properties, and to the different degree of interaction with the liposomal membrane. The disc-like shaped LL-37 liposomes (106.8±10.1nm, shelf-life stability of >1year) were taken up more rapidly and to a significantly higher extent than the free peptide by human keratinocyte cell line (HaCaT), remained intact within the cells, followed by release of the active peptide within the cytoplasm and migration of the vesicles' lipids to the plasma membrane. LL-37 liposomes were found significantly less toxic than both the free agent and liposomal indolicidin. In the new 3D epidermis model (immortalized primary keratinocytes) liposomal LL-37 treatment (>20μM), but not free LL-37, efficiently protected the epidermis, inhibiting HSV-1 infection. This positive antiviral effect was obtained with no cytotoxicity even at very high concentrations (400μM). Thus, the antiviral activity of encapsulated LL-37 was significantly improved, expanding its therapeutic window. Liposomal LL-37 appears to be a promising delivery system for HSV therapy.
阳离子抗菌肽（AMPs）是先天免疫系统的一部分，通过扰乱微生物的质膜来对抗各种致病微生物。尽管这些药物在临床上很有吸引力，但由于在体内稳定性和活性有限，以及与宿主生物膜的非特异性相互作用，导致细胞毒性不良反应，因此它们的应用受到限制。我们假设将 AMP 封装在脂质体中可以降低细胞毒性，并增强稳定性以及对单纯疱疹病毒 1（HSV-1）的生物活性。我们制备了 LL-37 和吲哚西林的纳米级脂质体配方，并确定了它们的理化性质、细胞摄取、体外细胞毒性和抗病毒功效。与吲哚西林脂质体相比，LL-37 脂质体的细胞毒性更低，这归因于其优越的理化性质以及与脂质体膜的不同相互作用程度。盘状的 LL-37 脂质体（106.8±10.1nm，保质期稳定性>1 年）比游离肽更快、更高程度地被人角质形成细胞系（HaCaT）摄取，在细胞内保持完整，随后细胞质内释放活性肽，并将囊泡的脂质迁移到质膜。与游离剂和脂质体吲哚西林相比，LL-37 脂质体的毒性明显降低。在新的 3D 表皮模型（永生化原代角质形成细胞）中，脂质体 LL-37 处理（>20μM），而不是游离的 LL-37，有效地保护了表皮，抑制了 HSV-1 感染。即使在非常高的浓度（400μM）下，也没有产生细胞毒性，从而获得了这种积极的抗病毒作用。因此，包封的 LL-37 的抗病毒活性得到了显著改善，扩大了其治疗窗口。脂质体 LL-37 似乎是治疗 HSV 的一种很有前途的递药系统。
