Near-infrared (NIR) light-triggered and separable segmented microneedles (MNs), consisting of lauric acid and polycaprolactone (LA/PCL) arrowheads and poly(vinyl alcohol) and polycaprolactone (PVA/PVP) supporting bases, have been fabricated. A hypoglycemic drug (metformin) and photothermal conversion factor (Cu₇S₄ nanoparticles) are encapsulated into LA/PCL arrowheads. Due to the dissolution of soluble supporting bases after the absorption of tissue fluid, the separable MNs arrowheads can be embedded into skin after insertion. Under the NIR-light irradiation, the LA/PCL arrowheads exhibit an excellent thermal-ablation change with a low amount of Cu₇S₄ nanoparticles (0.1 wt %) due to the low melting point of LA and PCL, thus enabling the release behavior of the encapsulated model drug to be photothermally triggered. Compared to the hypodermic injection of metformin, the thermal ablation of separable MNs triggered by NIR irradiation in the current research exhibit an excellent hypoglycemic effect in vivo. It suggests that the NIR-induced thermal-ablation MNs comprise a prospective transdermal drug-delivery system for the precise control of the timing and dosage of a drug that is dependent on NIR administration.

中文翻译：

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可分离的微针二甲双胍在糖尿病大鼠中的近红外光触发透皮递送。

已制造出由月桂酸和聚己内酯（LA / PCL）箭头以及聚乙烯醇和聚己内酯（PVA / PVP）支撑基质组成的近红外（NIR）光触发且可分离的分段微针（MNs）。降糖药（二甲双胍）和光热转化因子（Cu ₇ S ₄纳米粒子）被封装在LA / PCL箭头中。由于吸收组织液后可溶性支持碱的溶解，可分离的MNs箭头可在插入后嵌入皮肤中。在近红外光照射下，LA / PCL箭头显示出优异的热烧蚀变化，且铜₇ S ₄含量低由于LA和PCL的低熔点，纳米颗粒（0.1重量％），因此使得能够通过光热触发包封的模型药物的释放行为。与皮下注射二甲双胍相比，当前研究中由NIR辐射引发的可分离MN的热消融在体内表现出出色的降血糖作用。这表明，NIR诱导的热消融MN包括一个预期的透皮给药系统，用于精确控制依赖于NIR给药的药物的时机和剂量。