Center for Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
Expert Opin Drug Deliv. 2013 Jun;10(6):787-97. doi: 10.1517/17425247.2013.776038. Epub 2013 Mar 27.
The optimization of drug delivery to and via the hair follicles is gaining more and more importance as it has been recognized that the hair follicles are an interesting target site for topical applications. They are closely surrounded by capillaries and antigen-presenting cells, are associated with the sebaceous glands and are the host of stem cells in the bulge region of the hair follicle.
The present review shortly summarizes the complexity of the structure, biology and functions of the hair follicle and presents the models and methods suitable to investigate follicular penetration. Drug delivery to hair follicles was clearly shown to be dependent on the physicochemical properties of the applied substances and vehicles as well as on the activity status, size and density of the hair follicles. Especially particulate substances were demonstrated to be proficient drug carriers into the hair follicles, whereas dependent data for transfollicular penetration into the deeper viable skin layers could only be found for non-particulate substances which then, however, received rapid access to the circulation when the follicular pathway was accessible.
Promising concepts to optimize hair follicle delivery and to beneficially utilize particulate substances for efficient follicular drug delivery are the application of external or internal stimuli for controlled drug release from the particles such as the combined application with protease or the usage of gold nanoparticles in combination with near-infrared irradiation.
由于人们认识到毛囊是局部应用的一个有趣的靶标，因此将药物递送至毛囊并通过毛囊进行优化越来越重要。毛囊被毛细血管和抗原呈递细胞紧密包围，与皮脂腺相关，并且是毛囊隆起区域干细胞的宿主。
本综述简要总结了毛囊的结构、生物学和功能的复杂性，并介绍了适合研究毛囊穿透的模型和方法。研究表明，药物向毛囊的传递明显依赖于所应用物质和载体的物理化学性质，以及毛囊的活性状态、大小和密度。特别是颗粒物质被证明是进入毛囊的高效药物载体，而对于非颗粒物质的透皮穿透进入更深的存活皮肤层的相关数据，只有当毛囊途径可及时，这些物质才能迅速进入循环。
优化毛囊传递并利用颗粒物质进行有效的毛囊药物传递的有前景的概念是应用外部或内部刺激来控制从颗粒中释放药物，例如与蛋白酶联合应用或与近红外辐射联合使用金纳米颗粒。
