title: Multibuilding Block Janus Synthesized by Seed-Mediated Self-Assembly for Enhanced Photothermal Effects and Colored Brownian Motion in an Optical Trap.
abstract: The asymmetrical features and unique properties of multibuilding block Janus nanostructures (JNSs) provide superior functions for biomedical applications. However, their production process is very challenging. This problem has hampered the progress of JNS research and the exploration of their applications. In this study, an asymmetrical multibuilding block gold/iron oxide JNS has been generated to enhance photothermal effects and display colored Brownian motion in an optical trap. JNS is formed by seed-mediated self-assembly of nanoparticle-loaded thermocleavable micelles, where the hydrophobic backbones of the polymer are disrupted at high temperatures, resulting in secondary self-assembly and structural rearrangement. The JNS significantly enhances photothermal effects compared to their homogeneous counterpart after near-infrared (NIR) light irradiation. The asymmetrical distribution of gold and iron oxide within JNS also generates uneven thermophoretic force to display active colored Brownian rotational motion in a single-beam gradient optical trap. These properties indicate that the asymmetrical JNS could be employed as a strong photothermal therapy mediator and a fuel-free nanoscale Janus motor under NIR light.
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, 48109, USA.
authors.forename: Kanokwan
authors.initials: K
authors.lastname: Sansanaphongpricha
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, 48109, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: DeSantis
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, 48109, USA.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, 48109, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.affiliation: Department of Material Sciences and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Sun
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, 48109, USA.
authors.forename: Bo
authors.initials: B
authors.lastname: Wen
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, 48109, USA.
authors.forename: Duxin
authors.initials: D
authors.lastname: Sun
mesh_terms: D045744:Cell Line, Tumor; D003116:Color; D005290:Ferric Compounds / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006801:Humans; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009038:Motion; D052898:Optical Tweezers; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry; D013696:Temperature
chemical_list: D005290:Ferric Compounds; D011108:Polymers; C000499:ferric oxide; D006046:Gold
keywords: Diels-Alder reaction; Janus motors; optical tweezers; thermocleavable polymers; thermophoresis