title: Comparison of biocompatibility and adsorption properties of different plastics for advanced microfluidic cell and tissue culture models.
abstract: Microfluidic technology is providing new routes toward advanced cell and tissue culture models to better understand human biology and disease. Many advanced devices have been made from poly(dimethylsiloxane) (PDMS) to enable experiments, for example, to study drug metabolism by use of precision-cut liver slices, that are not possible with conventional systems. However, PDMS, a silicone rubber material, is very hydrophobic and tends to exhibit significant adsorption and absorption of hydrophobic drugs and their metabolites. Although glass could be used as an alternative, thermoplastics are better from a cost and fabrication perspective. Thermoplastic polymers (plastics) allow easy surface treatment and are generally transparent and biocompatible. This study focuses on the fabrication of biocompatible microfluidic devices with low adsorption properties from the thermoplastics poly(methyl methacrylate) (PMMA), polystyrene (PS), polycarbonate (PC), and cyclic olefin copolymer (COC) as alternatives for PDMS devices. Thermoplastic surfaces were oxidized using UV-generated ozone or oxygen plasma to reduce adsorption of hydrophobic compounds. Surface hydrophilicity was assessed over 4 weeks by measuring the contact angle of water on the surface. The adsorption of 7-ethoxycoumarin, testosterone, and their metabolites was also determined after UV-ozone treatment. Biocompatibility was assessed by culturing human hepatoma (HepG2) cells on treated surfaces. Comparison of the adsorption properties and biocompatibility of devices in different plastics revealed that only UV-ozone-treated PC and COC devices satisfied both criteria. This paper lays an important foundation that will help researchers make informed decisions with respect to the materials they select for microfluidic cell-based culture experiments.
authors.affiliation: Pharmaceutical Analysis, Department of Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands.
authors.forename: Paul M
authors.initials: PM
authors.lastname: van Midwoud
authors.forename: Arnout
authors.initials: A
authors.lastname: Janse
authors.forename: Marjolijn T
authors.initials: MT
authors.lastname: Merema
authors.forename: Geny M M
authors.initials: GM
authors.lastname: Groothuis
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Verpoorte
mesh_terms: D000327:Adsorption; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism*; D002470:Cell Survival; D003516:Cycloparaffins / Q000737:chemistry / Q000378:metabolism*; D004867:Equipment Design; D056945:Hep G2 Cells; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D010084:Oxidation-Reduction; D011076:Polycarboxylate Cement / Q000737:chemistry / Q000378:metabolism*; D019904:Polymethyl Methacrylate / Q000737:chemistry / Q000378:metabolism*; D011137:Polystyrenes / Q000737:chemistry / Q000378:metabolism*; D046509:Tissue Culture Techniques / Q000295:instrumentation*
chemical_list: D001672:Biocompatible Materials; D003516:Cycloparaffins; D011076:Polycarboxylate Cement; D011137:Polystyrenes; C005506:polycarbonate; D019904:Polymethyl Methacrylate