Fiber Optic Microneedles for Transdermal Light Delivery: Ex Vivo Porcine Skin Penetration Experiments
Fiber Optic Microneedles for Transdermal Light Delivery: Ex Vivo Porcine Skin Penetration Experiments
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DOI：
10.1115/1.4002192
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发表时间：
2010-09-01
影响因子：
1.7
通讯作者：
Rylander, Christopher G.
中科院分区：
文献类型：
--
作者：
Kosoglu, Mehmet A.;Hood, Robert L.;Rylander, Christopher G.
组织中的浅光穿透一直是开发用于上皮癌的体内诊断和治疗的基于光的方法的技术障碍。这个问题可以通过利用微创探头将光直接传递到目标区域来解决。为了开发这种解决方案，能够传递用于成像或治疗的光的光纤微针通过采用熔融拉伸工艺使阶跃折射率二氧化硅基光纤变细来制造。通过在熔融拉伸过程中改变热源，一些微针被制造成具有更尖锐的尖端。将所有微针单独插入离体猪皮肤样品中，以证明其在人体组织中应用的可行性。在插入过程中测量每个微针上的力，以确定更尖锐的尖端对峰值力和力增加的稳定性的影响。皮肤穿透实验表明，3 mm长的尖锐光纤微针穿透2 mm的离体猪皮样本。这些尖锐的微针具有73 μ π ι的最小平均直径和8 μ π ι的最大尖端直径。具有较大尖端直径的扁平微针需要125 μ m的最小平均直径以穿透猪皮样品。力与位移图显示，光纤微针上的尖锐尖端降低了插入过程中皮肤的阻力。此外，与具有平坦尖端的微针相比，作用在尖锐微针上的力更稳定地增加。然而，许多尖锐的微针在皮肤穿透过程中受到损伤。确定了两种未产生损伤的设计，并将为更耐用的微针提供基础。开发具有更小直径的弹性微针将导致变革性的、新颖的经皮成像和治疗模式，这些模式对患者的侵入性更小，痛苦更小。[DOI：10.1115/1.4002192]
Shallow light penetration in tissue has been a technical barrier to the development of light-based methods for in vivo diagnosis and treatment of epithelial carcinomas. This problem can potentially be solved by utilizing minimally, invasive probes to deliver light directly to target areas. TO develop this solution, fiber optic microneedles capable of delivering light for either imaging or therapy were manufactured by tapering step-index silica-based optical fibers employing a melt-drawing process. Some of the microneedles were manufactured to have sharper tips by changing the heat source during the melt-drawing process. All of the microneedles were individually inserted into ex vivo pig skin samples to demonstrate the feasibility of their application in human tissues. The force on each microneedle was measured during insertion in order to determine the effects of sharper tips on the peak force and the steadiness of the increase in force. Skin penetration experiments showed that sharp fiber optic microneedles that are 3 mm long penetrate through 2 mm of ex vivo pig skin specimens. These sharp microneedles had a minimum average diameter of 73 pm and a maximum tip diameter of 8 Am. Flat microneedles, which had larger tip diameters, required a minimum average diameter of 125 tun in order to penetrate through pig skin samples. Force versus displacement plots showed that a sharp tip on a fiber optic microneedle decreased the skin's resistance during insertion. Also, the force acting on a sharp microneedle increased more steadily compared with a microneedle with a flat tip. However, many of the sharp microneedles sustained damage during skin penetration. Two designs that did not accrue damage were identified and will provide a basis of more robust microneedles. Developing resilient microneedles with smaller diameters will lead to transformative, novel modes of transdermal imaging and treatment that are less invasive and less painful for the patient. [DOI: 10.1115/1.4002192]