The need for novel, minimally invasive diagnostic, prognostic, and therapeutic biomedical devices has garnered increased interest in recent years. Microneedle (MN) technology has stood out as a promising new method for drug delivery, as well as extraction of interstitial fluid (ISF). ISF comprises a large portion of the extracellular fluid in living organisms yet remains inadequately characterized for clinical applications. Current MN research has focused on the fabrication of needles with different materials like silicone, carbon, and metals. However, little effort has been put forth into improving MN holders and patches that can be used with low cost MNs, which could effectively change how MNs are attached to the human body. Here, we describe different 3D-printed MN holders, printed using an MJP Pro 2500 3D printer, and compare the ISF extraction efficiencies in CD Hairless rats. We varied design parameters that may affect the skin-holder interface, such as throat thickness, tip curvature, and throat diameter. MN arrays, with insertion depths of 1500 μm, had extraction efficiencies of 0.44 ± 0.35, 0.85 ± 0.64, 0.32 ± 0.21, or 0.44 ± 0.46 µl/min when designed with flat, concave, convex, or bevel profile geometries, respectively. Our results suggest ISF extraction is influenced by MN holder design parameters and that a concave tip design is optimal for extracting ISF from animals. The future direction of this research aims to enable a paradigm in MN design that maximizes its efficiency and engineering performance in terms of volume, pressure, and wearability, thereby automatizing usage and reducing patient intervention to ultimately benefit remote telemedicine.

近年来，对新型、微创诊断、预后和治疗生物医学设备的需求越来越受到关注。微针 (MN) 技术已脱颖而出，成为一种很有前途的药物输送新方法，以及组织液 (ISF) 的提取方法。ISF 包含活生物体中的大部分细胞外液，但仍未充分表征临床应用。目前的 MN 研究主要集中在使用不同材料（如硅树脂、碳和金属）制造针头。然而，很少有人努力改进可与低成本 MN 一起使用的 MN 支架和贴片，这可以有效地改变 MN 与人体的附着方式。在这里，我们描述了不同的 3D 打印 MN 支架，使用 MJP Pro 2500 3D 打印机打印，并比较 CD 无毛大鼠的 ISF 提取效率。我们改变了可能影响皮肤支架界面的设计参数，例如喉部厚度、尖端曲率和喉部直径。插入深度为 1500 μm 的 MN 阵列在设计为平面、凹面、凸面或斜面轮廓几何形状时，提取效率分别为 0.44 ± 0.35、0.85 ± 0.64、0.32 ± 0.21 或 0.44 ± 0.46 µl/min。我们的结果表明 ISF 提取受 MN 支架设计参数的影响，并且凹形尖端设计最适合从动物中提取 ISF。这项研究的未来方向旨在实现 MN 设计的范例，最大限度地提高其在体积、压力和可穿戴性方面的效率和工程性能，从而使使用自动化并减少患者干预，最终使远程医疗受益。