Department of Physics, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
Drug Deliv Transl Res. 2019 Oct;9(5):956-967. doi: 10.1007/s13346-019-00638-x.
Optical poration, or drilling, of the human nail has the potential to drastically improve transungual drug delivery. However, this approach is accompanied by thermal damage to the nail tissue surrounding the laser radiation-created pore. In this paper, fluorescence microscopy has been employed to quantitatively evaluate thermal damage to the nail induced by laser ablation with 80 MHz, nanojoule, femtosecond pulses delivered via a hollow-core fibre. An empirical relation has been established between the intensity of the resulting fluorescence signal and temperature to which the nail was exposed. Using this relationship, detailed temperature maps have been created of the areas surrounding the pores, enabling the mechanism of poration to be better understood. It was deduced that plasma-mediated ablation is primarily responsible for nail tissue ablation at the centre of the pore, while cumulative photothermal processes dominate at the pore edges. It is concluded, furthermore, that temperature mapping represents a useful new tool with which to optimise the process of nail poration. The method is potentially generic and may be applicable to other biological materials.
激光微穿孔技术有望显著改善经皮药物递送。然而，这种方法伴随着激光辐射产生的孔周围指甲组织的热损伤。在本文中，荧光显微镜被用于通过空心光纤传输的 80MHz、纳焦耳、飞秒脉冲的激光烧蚀来定量评估指甲的热损伤。已经建立了荧光信号强度与指甲暴露温度之间的经验关系。利用这种关系，创建了围绕孔的区域的详细温度图，从而更好地理解穿孔的机制。推断出等离子体介导的烧蚀主要负责孔中心的指甲组织烧蚀，而累积光热过程则在孔边缘起主导作用。此外，还得出结论，温度映射是一种优化指甲穿孔过程的有用新工具。该方法具有普遍性，可能适用于其他生物材料。
