Jung Sascha, Otberg Nina, Thiede Gisela, Richter Heike, Sterry Wolfram, Panzner Steffen, Lademann Jürgen
Department of Dermatology, Centre of Experimental and Applied Cutaneous Physiology, University Clinic Berlin, Berlin, Germany.
J Invest Dermatol. 2006 Aug;126(8):1728-32. doi: 10.1038/sj.jid.5700323. Epub 2006 Apr 27.
Liposomes had been widely used for drug delivery in the past. In this study, five different liposomes were used as a follicular delivery system in pig ear skin. The liposomes mainly differed in their sphere diameter, lipid composition, and surface charge. A novel class of liposomes being amphoteric in their charge behavior are compared to established anionic and cationic liposomes. Two different fluorescent dyes, hydrophilic carboxyfluoresceine or lipophilic curcumin, were enclosed in the liposomes and used as model drugs. The fluorescent dyes were also applied in a standard formulation for reference. The penetration depth of the dyes was measured by laser scanning microscopy in histological sections. One hour, 3, 5, and 7 days after application, biopsies were taken and the penetration depth into the hair follicle was measured in longitudinal sections. The liposomes showed a higher penetration depth compared to the standard formulation. The relative penetration depth of the dyes, applied in the standard formulation, averaged 30% of the full follicle length during the whole observation period, whereas the liposomal formulations penetrated considerably deeper into the hair follicles. Amphoteric and cationic liposomes reached an average relative penetration depth of approximately 70% of the full hair follicle length.
过去，脂质体已被广泛用于药物递送。在本研究中，五种不同的脂质体被用作猪耳皮肤的毛囊递送系统。这些脂质体主要在球体直径、脂质组成和表面电荷方面存在差异。将一类新型的具有两性电荷行为的脂质体与已有的阴离子和阳离子脂质体进行比较。两种不同的荧光染料，亲水性的羧基荧光素或亲脂性的姜黄素，被包裹在脂质体中并用作模型药物。荧光染料也以标准制剂形式应用作为对照。通过激光扫描显微镜在组织切片中测量染料的渗透深度。在应用后1小时、3天、5天和7天，进行活检，并在纵切面上测量染料进入毛囊的渗透深度。与标准制剂相比，脂质体显示出更高的渗透深度。在整个观察期内，以标准制剂形式应用的染料的相对渗透深度平均为整个毛囊长度的30%，而脂质体制剂进入毛囊的深度要深得多。两性脂质体和阳离子脂质体的平均相对渗透深度约为整个毛囊长度的70%。
