Pham Hong-Phuc, Vo Van-Toi, Nguyen Thanh-Qua
School of Biomedical Engineering, International University, Ho Chi Minh City, Vietnam.
Vietnam National University, Ho Chi Minh City, Vietnam.
Drug Deliv Transl Res. 2025 Jul;15(7):2431-2447. doi: 10.1007/s13346-024-01740-5. Epub 2024 Nov 18.
Microneedle technology has emerged as an advanced method for transdermal drug delivery, which focuses on diverse fabrication techniques to develop microneedles with various models and geometries. This study explores the application of Computer Numerical Control (CNC) milling technology to create microneedle master molds with extremely sharp tips. We examined the effects of two key machining parameters, feed rate and ramp angle, on the tip sharpness of the microneedles. Our results showed that increasing both the feed rate and ramp angle could significantly reduce machining time. However, a higher feed rate also led to larger tip diameters and notable tip defects. Conversely, changes in the ramp angle at a constant feed rate had minimal impact on tip size. We identified an optimal condition balancing cutting time and tip sharpness at a feed rate of 100 mm/min and a ramp angle of 1.5°. Additionally, we assessed the CNC's capability to produce needles with different tip angles. The findings confirm that needles with varying tip angles maintained tip diameters below 10 μm, with needles having a 50° tip angle exhibiting the sharpest tips at approximately 3.3 μm. Further compression, insertion and diffusion tests were conducted to evaluate the performance of needles with different geometries.
微针技术已成为一种先进的经皮给药方法，该技术专注于多种制造技术，以开发具有各种模型和几何形状的微针。本研究探索了计算机数控（CNC）铣削技术在制造具有极尖锐尖端的微针母模方面的应用。我们研究了两个关键加工参数，即进给速度和斜角，对微针尖端锐度的影响。我们的结果表明，提高进给速度和斜角均可显著减少加工时间。然而，较高的进给速度也会导致更大的尖端直径和明显的尖端缺陷。相反，在恒定进给速度下改变斜角对尖端尺寸的影响最小。我们确定了在进给速度为100毫米/分钟和斜角为1.5°时，平衡切削时间和尖端锐度的最佳条件。此外，我们评估了CNC生产具有不同尖端角度的针的能力。研究结果证实，不同尖端角度的针的尖端直径保持在10μm以下，其中尖端角度为50°的针在约3.3μm处表现出最尖锐的尖端。还进行了进一步的压缩、插入和扩散测试，以评估不同几何形状的针的性能。
