title: Nanocomposite-strengthened dissolving microneedles for improved transdermal delivery to human skin.
abstract: Delivery of drugs and biomolecules into skin has significant advantages. To achieve this, herein, a nanomaterial-strengthened dissolving microneedle patch for transdermal delivery is reported. The patch comprises thousands of microneedles, which are composed of dissolving polymers, nanomaterials, and drug/biomolecules in their interior. With the addition of nanomaterials, the mechanical property of generally weak dissolving polymers can be dramatically improved without sacrificing dissolution rate within skin. In this experiments, layered double hydroxides (LDH) nanoparticles are incorporated into sodium carboxymethylcellulose (CMC) to form a nanocomposite. The results show that, by adding 5 wt% of LDH nanoparticles into CMC, the mechanical strength significantly increased. Small and densely packed CMC-LDH microneedles penetrate human and pig skin more reliably than pure CMC ones and attractively the nanocomposite-strengthened microneedles dissolve in skin and release payload within only 1 min. Finally, the application of using the nanocomposite-strengthened microneedle arrays is tested for in vivo vaccine delivery and the results show that significantly stronger antibody response could be induced when compared with subcutaneous injection. These data suggest that nanomaterials could be useful for fabricating densely packed and small polymer microneedles that have robust mechanical properties and rapid dissolution rates and therefore potential use in clinical applications.
authors.affiliation: Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR.
authors.forename: Li
authors.initials: L
authors.lastname: Yan
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Raphael
authors.forename: Xiaoyue
authors.initials: X
authors.lastname: Zhu
authors.forename: Beilei
authors.initials: B
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Tao
authors.initials: T
authors.lastname: Tang
authors.forename: Yan
authors.initials: Y
authors.lastname: Deng
authors.forename: Himanshu J
authors.initials: HJ
authors.lastname: Sant
authors.forename: Guangyu
authors.initials: G
authors.lastname: Zhu
authors.forename: Kwong Wai
authors.initials: KW
authors.lastname: Choy
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Gale
authors.forename: Tarl W
authors.initials: TW
authors.lastname: Prow
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Chen
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry; D016503:Drug Delivery Systems / Q000295:instrumentation*; D006801:Humans; D006878:Hydroxides / Q000737:chemistry; D008845:Microinjections / Q000295:instrumentation*; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D009339:Needles; D010047:Ovalbumin / Q000008:administration & dosage / Q000737:chemistry / Q000276:immunology / Q000493:pharmacokinetics; D013552:Swine
chemical_list: D006878:Hydroxides; D010047:Ovalbumin; D002266:Carboxymethylcellulose Sodium
keywords: biomedical applications; nanocomposite; polymeric material; transdermal delivery; vaccine delivery