Lee KangJu, Park Seung Hyun, Lee JiYong, Ryu Suho, Joo Chulmin, Ryu WonHyoung
Department of Mechanical Engineering, Yonsei University, Yonsei-ro 50, Seoul 03722, Korea.
Pharmaceutics. 2019 Feb 26;11(3):100. doi: 10.3390/pharmaceutics11030100.
Microneedles (MNs) have been extensively developed over the last two decades, and highly efficient drug delivery was demonstrated with their minimal invasiveness via a transdermal route. Recently, MNs have not only been applied to the skin but also to other tissues such as blood vessels, scleral tissue, and corneal tissue. In addition, the objective of the MN application has been diversified, ranging from drug delivery to wound closure and biosensing. However, since most MN fabrication methods are expensive and time-consuming, they are inappropriate to prototype MNs for various tissues that have different and complex anatomies. Although several drawing-based techniques have been introduced for rapid MN production, they fabricated MNs with limited shapes, such as thin MNs with wide bases. In this study, we propose a three-step thermal drawing for rapid, prototyping MNs that can have a variety of shapes and can be fabricated on curved surfaces. Based on the temperature control of polymer bridge formation during thermal drawing, the body profile and aspect ratios of MNs were conveniently controlled, and the effect of temperature control on the body profile of MNs was explained. Thermally drawn MNs with different shapes were fabricated both on flat and curved surfaces, and they were characterized in terms of their mechanical properties and insertion into vascular tissue to find an optimal shape for vascular tissue insertion.
在过去二十年中，微针（MNs）得到了广泛的发展，并且通过经皮途径以其最小的侵入性证明了高效的药物递送。最近，微针不仅已应用于皮肤，还应用于其他组织，如血管、巩膜组织和角膜组织。此外，微针的应用目标已经多样化，从药物递送、伤口闭合到生物传感。然而，由于大多数微针制造方法既昂贵又耗时，它们不适用于为具有不同和复杂解剖结构的各种组织制作微针原型。尽管已经引入了几种基于绘图的技术来快速生产微针，但它们制造的微针形状有限，例如基部较宽的细微针。在本研究中，我们提出了一种三步热拉伸法来快速制作微针原型，该微针可以具有多种形状并且可以在曲面上制造。基于热拉伸过程中聚合物桥形成的温度控制，方便地控制了微针的主体轮廓和纵横比，并解释了温度控制对微针主体轮廓的影响。在平面和曲面上都制造了不同形状的热拉伸微针，并对它们的力学性能和插入血管组织的情况进行了表征，以找到血管组织插入的最佳形状。
