Development of Medical Micro Needle Made of Biodegradable Material

可生物降解材料医用微针的研制

• 批准号: 16310103
• 负责人: AOYAGI Seiji
• 金额: $ 10.37万
• 依托单位: Kansai University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16310103/
• 关键词: Micro Needle; Biodegradable Material; Micro Molding; Excimer Laser Machining; Micromachining

The aim of this research is the development of micro needle, of which outer shape is jagged imitating the mosquito. This needle would be effective for reducing pain and fear when penetrating a needle into skin, realizing a trace blood system, realizing a portable glucose level measurement system for diabetics, etc. As the structural material, biodegradable polymer of PLA (Poly Lactic Acid) is employed. In this year, the following items are tried and successful results are obtained : 1) establishment of fabrication process of solid needle by micro molding method for PLA material, 2) estimation of resistance force during insertion to artificial skin of silicone rubber, 3) development of fabrication method of drilling the high aspect ratio hole to the solid PLA needle by excimer laser, 4) sampling blood by capillary force. As for 1), optimal condition of injection temperature and injection pressure is searched. As the result, it is proved that setting the temperature to just above the melting point of PLA and setting the pressure to the allowable maximal value of the injection machine lead to realizing a surely rigid needle bearing the insertion to human skin. As for 2), a measuring system of resistance force during insertion is newly developed. This system employs a high performance load cell and combines it with a 1DOF linear stage, all function of which are controlled by a personal computer. It is proved that the sharp tip and thin shank is effective for reducing the resistance force. However, the effect of jagged shape is not prominent on reducing the force. As for 3), a hole with high aspect ratio of 20 micro meter diameter and 1mm length is realized. As for 4), it is observed by a zoom microscope that the blood surely runs up inside the hole of the needle.

这项研究的目的是开发微型针，其外形呈锯齿状，模仿蚊子。该针可有效减少针刺入皮肤时的疼痛和恐惧，实现微量血液系统，实现糖尿病患者的便携式血糖水平测量系统等。作为结构材料，采用可生物降解的PLA（聚乳酸）聚合物。今年，我们尝试了以下项目，并取得了成功的成果：1）PLA材料微成型法实心针制造工艺的建立，2）硅橡胶人造皮肤插入过程中阻力的估计，3）准分子激光在实心PLA针上钻高深宽比孔的制造方法的开发，4）毛细管力采样血液。对于1)，搜索注射温度和注射压力的最佳条件。结果证明，将温度设置为略高于PLA的熔点并将压力设置为注射机允许的最大值可以实现具有牢固插入人体皮肤的针头。对于2)，新开发了插入时阻力的测量系统。该系统采用高性能称重传感器，并将其与一自由度线性平台相结合，所有功能均由个人计算机控制。实践证明，尖尖细柄对于减小阻力是有效的。但锯齿形状对于减小力的效果并不突出。对于3)，实现了直径20微米、长度1mm的高深宽比的孔。对于4)，通过变焦显微镜观察，血液确实在针孔内向上流动。