Teichmann A, Ossadnik M, Richter H, Sterry W, Lademann J
Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Medical Faculty Charité, Berlin, Germany.
Skin Pharmacol Physiol. 2006;19(2):101-5. doi: 10.1159/000091977. Epub 2006 May 9.
Recently, hair follicles were shown to be of great importance concerning the penetration and reservoir behavior of topically applied substances. Especially microparticles are known to be efficient drug carriers into the hair follicles. It has been shown in various investigations that, depending on their size, microparticles can be utilized to enhance the penetration of substances into the hair follicles. In the present study, it was investigated whether they could also be used to block the hair follicles to stop penetration. For this purpose, the follicular penetration of a sodium fluorescein-containing hydrogel and follicular reservoir depletion were investigated by means of differential stripping in vivo. In a second study design, the skin areas were pretreated with microparticles 5 microm in diameter. Subsequently, the follicular penetration of sodium fluorescein-containing hydrogel was likewise investigated by differential stripping. The results showed that the hair follicle infundibula contained a significant fluorescent signal when sodium fluorescein in hydrogel was applied. In contrast, in the case of pretreatment with microparticles, only a very low fluorescence signal was measurable in the hair follicle infundibula. The microparticles clearly blocked the follicular orifices so that a penetration of sodium fluorescein was almost completely inhibited. This was confirmed by histological investigations. Thus, depending on their size, microparticles act as efficient drug carriers or can be utilized as follicle blockers to stop the penetration of topically applied substances. This could be very useful in skin protection to prevent the storage of harmful topically applied substances in the hair follicles, known to represent long-term reservoirs.
最近，毛囊被证明在局部应用物质的渗透和储库行为方面具有重要意义。特别是微粒被认为是进入毛囊的有效药物载体。各种研究表明，根据微粒的大小，它们可用于增强物质向毛囊的渗透。在本研究中，研究了它们是否也可用于阻塞毛囊以阻止渗透。为此，通过体内差异剥离研究了含荧光素钠水凝胶的毛囊渗透和毛囊储库消耗情况。在第二个研究设计中，用直径为5微米的微粒对皮肤区域进行预处理。随后，同样通过差异剥离研究了含荧光素钠水凝胶的毛囊渗透情况。结果表明，当应用含荧光素钠的水凝胶时，毛囊漏斗部含有显著的荧光信号。相比之下，在微粒预处理的情况下，在毛囊漏斗部仅可检测到非常低的荧光信号。微粒明显阻塞了毛囊孔口，从而几乎完全抑制了荧光素钠的渗透。组织学研究证实了这一点。因此，根据微粒的大小，它们可作为有效的药物载体，或可被用作毛囊阻滞剂以阻止局部应用物质的渗透。这在皮肤保护中可能非常有用，以防止有害的局部应用物质储存在已知为长期储库的毛囊中。
