title: Near-infrared light-responsive composite microneedles for on-demand transdermal drug delivery.
abstract: This study presents near-infrared (NIR) light-responsive polymer-nanostructure composite microneedles used for on-demand transdermal drug delivery. Silica-coated lanthanum hexaboride (LaB6@SiO2) nanostructures were incorporated into polycaprolactone microneedles, serving as an NIR absorber. When the microneedles were irradiated with NIR light, light-to-heat transduction mediated by the LaB6@SiO2 nanostructures caused the microneedle melting at 50 °C. This increased the mobility of the polymer chains, enabling drug release from the matrix. Drug release from the microneedles was evaluated for four laser on/off cycles. In each cycle, the samples were irradiated until the temperature reached 50 °C for 3 min (laser on); the laser was then turned off for 30 min (laser off). The results showed that light-induced phase transition in the polymer triggered drug release from the melted microneedles. A stepwise drug-release behavior was observed after multiple cycles of NIR light exposure. No notable drug leakage was found in the off state. This NIR-light-triggerable device exhibits excellent reproducibility, low off-state leakage, and noninvasive triggerability and, thus, represents an advance in transdermal delivery technology.
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Republic of China.
authors.forename: Mei-Chin
authors.initials: MC
authors.lastname: Chen
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Republic of China.
authors.forename: Ming-Hung
authors.initials: MH
authors.lastname: Ling
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Republic of China.
authors.forename: Kuan-Wen
authors.initials: KW
authors.lastname: Wang
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Republic of China.
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Lin
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Republic of China.
authors.forename: Bo-Hung
authors.initials: BH
authors.lastname: Lai
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Republic of China.
authors.forename: Dong-Hwang
authors.initials: DH
authors.lastname: Chen
mesh_terms: D000279:Administration, Cutaneous; D016503:Drug Delivery Systems; D065546:Drug Liberation / Q000528:radiation effects; D006801:Humans; D007259:Infrared Rays; D007811:Lanthanum / Q000737:chemistry / Q000627:therapeutic use; D049329:Nanostructures / Q000737:chemistry* / Q000627:therapeutic use; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry / Q000627:therapeutic use; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D011108:Polymers; D007811:Lanthanum; D012822:Silicon Dioxide