title: Controlled Release of an Anti-inflammatory Drug Using an Ultrasensitive ROS-Responsive Gas-Generating Carrier for Localized Inflammation Inhibition.
abstract: Inflammation is associated with many diseases, in which activated inflammatory cells produce various reactive oxygen species (ROS), including H2O2. This work proposes an ultrasensitive ROS-responsive hollow microsphere (HM) carrier that contains an anti-inflammatory drug, an acid precursor consisting of ethanol and FeCl2, and sodium bicarbonate (SBC) as a bubble-generating agent. In cases of inflamed osteoarthritis, the H2O2 at low concentration diffuses through the HMs to oxidize their encapsulated ethanol in the presence of Fe(2+) by the Fenton reaction, establishing an acidic milieu. In acid, SBC decomposes to form CO2 bubbles, disrupting the shell wall of the HMs and releasing the anti-inflammatory drug to the problematic site, eventually protecting against joint destruction. These results reveal that the proposed HMs may uniquely exploit biologically relevant concentrations of H2O2 and thus be used for the site-specific delivery of therapeutics in inflamed tissues.
authors.forename: Ming-Fan
authors.initials: MF
authors.lastname: Chung
authors.affiliation: Department of Orthopaedics, National Taiwan University Hospital Hsinchu Branch , Hsinchu 30013, Taiwan (ROC).
authors.forename: Wei-Tso
authors.initials: WT
authors.lastname: Chia
authors.forename: Wei-Lin
authors.initials: WL
authors.lastname: Wan
authors.forename: Yu-Jung
authors.initials: YJ
authors.lastname: Lin
authors.forename: Hsing-Wen
authors.initials: HW
authors.lastname: Sung
mesh_terms: D000893:Anti-Inflammatory Agents / Q000737:chemistry* / Q000494:pharmacology; D003692:Delayed-Action Preparations / Q000737:chemistry* / Q000494:pharmacology; D004337:Drug Carriers / Q000737:chemistry; D005740:Gases / Q000737:chemistry; D007249:Inflammation / Q000188:drug therapy*; D057230:Limit of Detection; D008863:Microspheres; D017382:Reactive Oxygen Species
chemical_list: D000893:Anti-Inflammatory Agents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005740:Gases; D017382:Reactive Oxygen Species