In vitro evaluation of platelet/biomaterial interactions in an epifluorescent video microscopy combined with a parallel plate flow cell.
Suitable evaluation systems are critical for ranking various biomaterials in order to develop a method to design and synthesize nonthrombogenic biomaterials. We have recently developed an in vitro test system to evaluate platelet/biomaterial interactions in whole blood. The system consists of a parallel plate flow cell and epifluorescent video microscopy (EVM). A glass coverslip coated with a polymer was incorporated into the flow cell, and blood was perfused using a syringe pump via a polymer-coated PVC tubing connected to the flow cell. Whole human blood was anticoagulated with heparin (2 U/ml), and the platelets were labeled with the fluorescent dye mepacrine (5 microM). This system permitted real-time and dynamic observations of platelet/biomaterial interactions in whole blood under a defined flow condition. In order to evaluate the feasibility of this system, two different segmented polyether-polyurethanes (SPEUs), PU-PTMG(650) and PU-PTMG(2000), were chosen as test polymers. Surface characteristics verified with electron spectroscopy for chemical analysis (ESCA) and contact angle measurements showed similar results in both SPEUs. Blood was perfused at a wall shear rate of 200 s-1 for 20 min. Excitation light was applied for 2 s at 1 min intervals. The real-time image was then analyzed at each time point for the percentage of surface area of platelet coverage. Plasma beta-thromboglobulin (beta-TG) levels were also measured before and after each run. PU-PTMG(650) showed a significantly higher number of adhered platelets than PU-PTMG(2000) at each time point.(ABSTRACT TRUNCATED AT 250 WORDS)
Kawagoishi
N
N
Institute of Biomedical Science, Terumo Corporation, Kanagawa, Japan.
Nojiri
C
C
Senshu
K
K
Kido
T
T
Nagai
H
H
Kanamori
T
T
Sakai
K
K
Koyanagi
H
H
Akutsu
T
T
D001672:Biocompatible Materials; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology*; D005456:Fluorescent Dyes; D006801:Humans; D008422:Materials Testing / Q000379:methods*; D008856:Microscopy, Fluorescence; D015539:Platelet Activation / Q000187:drug effects; D010973:Platelet Adhesiveness / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects; D011140:Polyurethanes; D011796:Quinacrine; D012212:Rheology / Q000295:instrumentation / Q000379:methods; D012235:Rhodamines; D013499:Surface Properties; D014741:Video Recording; D001620:beta-Thromboglobulin / Q000378:metabolism
D001672:Biocompatible Materials; D005456:Fluorescent Dyes; D011140:Polyurethanes; D012235:Rhodamines; D001620:beta-Thromboglobulin; C115016:polyetherurethane; C032527:acridine red; D011796:Quinacrine