Study on antithrombogenicity of poly[beta-(acetylsalicylyloxy)ethyl methacrylate] relative to poly(hydroxyethyl methacrylate).
The antithrombogenicity of a polymer made of aspirin bound to hydroxyethyl methacrylate (HEMA), abbreviated as ASA-polymer, was compared with that of poly(hydroxyethyl methacrylate) (PHEMA). Platelet from platelet rich plasma (PRP) incubated with ASA-polymer surface exhibited noticeable decreases in adhesion and aggregation as compared to platelets incubated with PHEMA. Low molecular weight components other than aspirin, which may be released from ASA-polymer during the incubation with PRP, or contact with ASA-polymer causing denaturation of platelets without morphological changes could be responsible for the decrease of adhesion and aggregation. Both PRP and PPP exposed to ASA-polymer-coated surfaces exhibited a much smaller partial thromboplastin time (PTT) than if exposed to PHEMA-coated surfaces; the PTT of ASA-polymer was similar to that of glass exposed plasma. With respect to the in vivo antithrombogenicity, the ASA-polymer surface led to thrombus formation. This may be due to the partial hydrolysis of the acetyl groups resulting in the formation of a negatively charged surface which in turn accelerates the coagulation cascade despite its inhibitory effects on platelet adhesion and aggregation. On the other hand, neointima formed around a thrombus layer on PHEMA-coated sutures after 14 days.
Sato
H
H
Research Center for Medical Polymers and Biomaterials, Kyoto University, Japan.
Kojima
J
J
Nakajima
A
A
Morita
T
T
Noishiki
Y
Y
Gu
Z W
ZW
Li
F M
FM
Feng
X D
XD
D000818:Animals; D001241:Aspirin / Q000031:analogs & derivatives* / Q000494:pharmacology; D001777:Blood Coagulation / Q000187:drug effects; D003692:Delayed-Action Preparations; D004285:Dogs; D005343:Fibrinolytic Agents; D066298:In Vitro Techniques; D015394:Molecular Structure; D010973:Platelet Adhesiveness / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors; D011102:Polyhydroxyethyl Methacrylate / Q000494:pharmacology*; D011109:Polymethacrylic Acids / Q000494:pharmacology*
D003692:Delayed-Action Preparations; D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D011109:Polymethacrylic Acids; D011102:Polyhydroxyethyl Methacrylate; C070156:poly(beta-(acetylsalicylyloxy)ethylmethacrylate); D001241:Aspirin