writer：Weijiang Yu, Guohua Jiang,* Yang Zhang, Depeng Liu, Bin Xu and Junyi Zhou
keywords：Transdermal delivery, microneedles, NIR
source：期刊
specific source：Journal of Materials Chemistry B, 2017, DOI: 10.1039/C7TB02236K
Issue time：2017年

Abstract: Near-infrared light triggered and separable microneedles (MNs) have been fabricated by separately molding method. The photothermal conversion agent(prussian blue nanoparticles,PB NPs)and hypoglycemic drug(metformin)have been embedded into the separable polycaprolactone (PCL) MNs arrowheads.These MNs arrowheads arecapped on dissolving polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) solid supporting substrate. The as-fabricated MNs exhibited an excellent photothermal conversion properties under near-infrared light (NIR) irradiation, causing the MNs arrowheads to melt due to the photothermal conversion of PB NPs. After applied on skin, the separable MNs arrowheads could be embedded in the skin due to the dissolving of supporting substrate after absorbing the interstitial fluid. When the embeddedMNsarrowheads were exposed to NIR irradiation, the MNs arrowheads undergone a rapid thermal ablation from a solid to a liquid state, thus enabling the release of encapsulated metformin to be NIR modulated. They allowed on-demand control of timing and dose of drug released. It suggests the developed NIR-triggered and separable MNs are a promising transdermal drug delivery system that enables the patient or physician to adjust therapy precisely in an active manner, thus, improving treatment efficiency and reducing side-effects.