title: Effects of surface wettability, flow, and protein concentration on macrophage and astrocyte adhesion in an in vitro model of central nervous system catheter obstruction.
abstract: While silicone devices have vastly improved an array of medical treatments, reactions at the tissue-substrate interface often impede their functionality. Insertion of a poly(dimethyl)siloxane (PDMS) catheter into the cerebral ventricles to drain excess cerebrospinal fluid (CSF) is the most common treatment of hydrocephalus, but shunting often fails because inflammatory tissue, choroid plexus cells, and debris grow into these central nervous system catheters and obstruct flow. We hypothesized that plasma oxidation of PDMS would inhibit macrophage and astrocyte adhesion under flow (0 to 0.3 mL/min) and protein (20.8 to 240 mg/dL) conditions similar to those observed in the physiological state. Oxidation (to increase wettability) had an inhibitory effect on macrophage cell binding (yielding a significant 88% change) that was generally more pronounced than the effect of flow (22% change) or protein concentration (3% change). In contrast, greater flow increased binding of astrocytes in most cases (yielding a significant 97% change); plasma oxidation (19% change), and protein concentration (60% change) had less pronounced effects. This study is the initial indicator that plasma oxidation of PDMS catheters may inhibit macrophage adhesion during CSF outflow but may not be as effective at inhibiting astrocyte binding.
authors.affiliation: Department of Neurosurgery and Division of Pediatric Neurosurgery, University of Utah, Salt Lake City, Utah 84132, USA. carolyn.harris@hsc.utah.edu
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Harris
authors.forename: James H
authors.initials: JH
authors.lastname: Resau
authors.forename: Eric A
authors.initials: EA
authors.lastname: Hudson
authors.forename: Richard A
authors.initials: RA
authors.lastname: West
authors.forename: Candice
authors.initials: C
authors.lastname: Moon
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Black
authors.forename: James P
authors.initials: JP
authors.lastname: McAllister
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D057785:Catheters; D002448:Cell Adhesion / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002490:Central Nervous System / Q000187:drug effects / Q000473:pathology*; D004129:Dimethylpolysiloxanes / Q000494:pharmacology; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism*; D007211:Indoles / Q000378:metabolism; D008264:Macrophages / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D051381:Rats; D012212:Rheology / Q000187:drug effects; D014867:Water; D017155:Wettability / Q000187:drug effects
chemical_list: D004129:Dimethylpolysiloxanes; D005904:Glial Fibrillary Acidic Protein; D007211:Indoles; D014867:Water; C007293:DAPI