title: Prospects for clinical applications of polymer-coated haemoconcentrator on extracorporeal circuit in cardiopulmonary bypass surgeries.
abstract: OBJECTIVE
  Extracorporeal circulation circuits used in cardiopulmonary bypass surgeries are increasingly being coated with polymer materials to reduce the thrombogenicity of extracorporeal devices. However, a haemoconcentrator, which corrects haematocrit and electrolyte imbalances, is not coated with polymers. In this study, we sought to assess the filtration performance of polymer-coated haemoconcentrators in order to obtain insight into their prospects for use in clinical applications.
  
  
  METHODS
  In vitro experiments were performed to evaluate the water pressure and flow properties of polymer-coated haemoconcentrators by comparing 3 polymer-coated haemoconcentrators with 3 non-coated haemoconcentrators. The cross-sectional surfaces of both types of haemoconcentrators were observed using a scanning electron microscope (SEM).
  
  
  RESULTS
  The slopes of the regression lines for estimating the filtrated fluid flow as a function of the transmembrane pressure were 6.286 ± 0.320 for polymer-coated haemoconcentrators and 3.712 ± 0.170 for non-coated haemoconcentrators. These slopes were found to be significantly different and indicate that the filtration velocity is enhanced in polymer-coated haemoconcentrators over that in non-coated haemoconcentrators. However, the hollow fibre damage observed by SEM was not shown to contribute to higher filtration flow in the polymer-coated haemoconcentrator. Taking these results into consideration, we hypothesise that a polymer coating makes a foreign surface on a hollow fibre slippery, owing to the hydrophobicity of the polymer, thereby enhancing the velocity of the filtration.
  
  
  CONCLUSIONS
  The results of this preliminary investigation suggest that a polymer coating can enhance the filtration performance of a haemoconcentrator and that polymer-coated haemoconcentrators might be useful in clinical applications.
authors.affiliation: Department of Medical Engineering, National Hospital Organization Kure Medical Centre and Chugoku Cancer Centre, Hiroshima - Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Tagaya
authors.affiliation: Department of Nephrology, National Hospital Organization Kure Medical Centre and Chugoku Cancer Centre, Hiroshima - Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Department of Internal Medicine, National Hospital Organization Kure Medical Centre and Chugoku Cancer Centre, Hiroshima - Japan.
authors.forename: Morihiro
authors.initials: M
authors.lastname: Matsuda
authors.affiliation: Division of Cardiovascular Surgery, National Hospital Organization Kure Medical Centre and Chugoku Cancer Centre, Hiroshima - Japan.
authors.forename: Taiichi
authors.initials: T
authors.lastname: Takasaki
authors.affiliation: Division of Cardiovascular Surgery, National Hospital Organization Kure Medical Centre and Chugoku Cancer Centre, Hiroshima - Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hamaishi
authors.affiliation: Department of Medical Engineering, National Hospital Organization Kure Medical Centre and Chugoku Cancer Centre, Hiroshima - Japan.
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Hara
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D002315:Cardiopulmonary Bypass / Q000295:instrumentation*; D020099:Coated Materials, Biocompatible; D005112:Extracorporeal Circulation / Q000295:instrumentation*; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D011108:Polymers / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D020099:Coated Materials, Biocompatible; D011108:Polymers; D006493:Heparin