Drug penetration through the skin is significant for both transdermal and dermal delivery. One mechanism that has attracted attention over the last two decades is the transport pathway of nanoparticles via hair follicle, through the epidermis, directly to the pilosebaceous unit and blood vessels. Studies demonstrate that particle size is an important factor for drug penetration. However, in order to gain more information for the purpose of improving this mode of drug delivery, a thorough understanding of the optimal physical particle properties is needed. In this study, we fabricated fluorescently labeled gold nanoparticles (GNP) with a tight control over the size and shape. The effect of the particles' physical parameters on follicular penetration was evaluated histologically. We used horizontal human skin sections and found that the optimal size for polymeric particles is 0.25 μm. In addition, shape penetration experiments revealed gold nanostars' superiority over spherical particles. Our findings suggest the importance of the particles' physical properties in the design of nanocarriers delivered to the pilosebaceous unit.

药物通过皮肤的渗透对于经皮和经皮给药都具有重要意义。在过去的二十年中引起关注的一种机制是纳米颗粒通过毛囊、通过表皮、直接到达毛囊皮脂腺单元和血管的运输途径。研究表明，粒径是药物渗透的重要因素。然而，为了获得更多信息以改进这种药物输送模式，需要彻底了解最佳物理颗粒特性。在这项研究中，我们制造了对尺寸和形状进行严格控制的荧光标记的金纳米粒子 (GNP)。在组织学上评估了颗粒物理参数对毛囊渗透的影响。我们使用水平人体皮肤切片，发现聚合物颗粒的最佳尺寸为 0.25 μm。此外，形状穿透实验揭示了金纳米星优于球形颗粒。我们的研究结果表明粒子的物理特性在设计纳米载体输送到毛囊皮脂腺单元中的重要性。