title: A magnetically controlled MEMS device for drug delivery: design, fabrication, and testing.
abstract: We report the development of a magnetically controlled drug delivery device for on-demand drug release to treat chronic diseases. The devices consist of drug-loaded micro-reservoirs (6 mm in diameter and ∼550 μm in depth), sealed by magnetic PDMS (polydimethylsiloxane) membranes (Ø 6 mm × 40 μm) with laser-drilled apertures and actuated by an external magnetic field. We present a detailed analysis of the magnetic actuation forces and provide an estimate of the resulting membrane deflections. The reservoirs are fabricated by PDMS molding and loaded with drugs using solvent evaporation methods. Post-processing procedures using bovine serum albumin (BSA) adsorption on magnetic PDMS surfaces are carried out to modify the surface wettability and to allow water filling and dissolution of the drugs in the reservoirs. Detailed surface modification processes are described and characterized. The device demonstrates on-demand delivery of methylene blue (MB) as a model drug. Intermittent magnetic actuations of the device in a ∼200 mT magnetic field show 10-fold increase in MB release compared to background release when the device is not actuated.
authors.affiliation: Department of Mechanical Engineering, University of British Columbia, 2054-6250 Applied Science Lane, Vancouver, Canada. pirmoradi@mech.ubc.ca
authors.forename: Fatemeh Nazly
authors.initials: FN
authors.lastname: Pirmoradi
authors.forename: John K
authors.initials: JK
authors.lastname: Jackson
authors.forename: Helen M
authors.initials: HM
authors.lastname: Burt
authors.forename: Mu
authors.initials: M
authors.lastname: Chiao
mesh_terms: D000327:Adsorption; D000818:Animals; D002417:Cattle; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D016503:Drug Delivery Systems / Q000295:instrumentation*; D004574:Electromagnetic Fields; D004867:Equipment Design; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008567:Membranes, Artificial; D008751:Methylene Blue / Q000737:chemistry / Q000493:pharmacokinetics; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D008956:Models, Chemical; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D004129:Dimethylpolysiloxanes; D058185:Magnetite Nanoparticles; D008567:Membranes, Artificial; D012710:Serum Albumin, Bovine; C013830:baysilon; D008751:Methylene Blue