To enhance the compliance of drug delivery for patients, the novel near-infrared (NIR) light-triggered and separable microneedles (MNs) have been developed in this work. Firstly, prussian blue nanoparticles (PB NPs) as the photo-thermal conversion factor and metformin as the hypoglycemic drug were embedded into the separable arrowheads, which consisted by poly (vinyl alcohol) and sucrose (PVA/Suc). The arrowheads of MNs were located on soluble solids supporting substrates that produced by poly(vinyl pyrrolidone) (PVP). Lauric acid (LA) as the phase transition coating covered on the surface of the MNs due to its lower phase transition temperature (~44 °C). Then, the separable arrowheads could be left into the skin because of the absorbing the interstitial fluid (IF) by the solid supporting substrates. With the irradiation of NIR light, LA could be melted due to the role of PB NPs in photo-thermal conversion, thus releasing the metformin from arrowheads. Compared with the traditional subcutaneous injections, the hypoglycemic effect was evaluated by the drug-release behaviors induced by NIR in vivo. The results showed that metformin could be allowed to on-demand release under the NIR irradiation. And the as-obtained MNs exhibited a good hypoglycemic effect, hypotoxicity and low inflammation reaction compared with those of traditional subcutaneous injections. The results indicate that the fabricated MNs have the potential treatment for diabetes due to their safety, convenience and painlessness.

中文翻译：

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具有相变涂层的可分离微针的制造，以用于糖尿病大鼠近红外触发的二甲双胍的透皮递送

为了提高对患者的药物输送的依从性，这项工作已经开发出新型的近红外（NIR）光触发和可分离的微针（MNs）。首先，将普鲁士蓝纳米颗粒（PB NPs）作为光热转换因子，将二甲双胍作为降血糖药嵌入到由聚乙烯醇和蔗糖（PVA / Suc）组成的可分离箭头中。MN的箭头位于由聚乙烯吡咯烷酮（PVP）产生的可溶性固体支持基质上。月桂酸（LA）作为相变涂层，由于其较低的相变温度（〜44°C）而覆盖在MN的表面上。然后，由于固体支撑基底吸收组织液（IF），可分离的箭头可能留在皮肤中。随着近红外光的照射，由于PB NP在光热转化中的作用，LA可能被熔化，从而从箭头释放二甲双胍。与传统的皮下注射相比，通过近红外光谱（NIR）诱导的药物释放行为评估了降血糖作用体内。结果表明，二甲双胍可以在近红外辐射下按需释放。与传统的皮下注射相比，获得的MNs具有良好的降血糖作用，低毒性和低炎症反应。结果表明，所制造的MN由于其安全性，便利性和无痛性而具有治疗糖尿病的潜力。