AVS 51st International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP15
Plasma Polymerization of Tetraglyme for PEO-like Surfaces and Plasma Immobilization of PEO Surfactants for Improved Blood Compatibility

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: J.L. Lauer, University of Wisconsin-Madison
Authors: J.L. Lauer, University of Wisconsin-Madison
J.L. Shohet, University of Wisconsin-Madison
R. Muguresan, University of Wisconsin-Madison
R.M. Albrecht, University of Wisconsin-Madison
U.H. von Andrian, Harvard Medical School
S. Esnault, University of Wisconsin-Madison
J.S. Malter, University of Wisconsin-Madison
S.B. Shohet, University of California, San Francisco
Correspondent: Click to Email
The realization of small scale biomedical devices will be closely related to the non-fouling/biocompatibility properties of the exposed surfaces and the uniformity of the surface treatment throughout the device. PEO and PEO-like surfaces are significantly advantageous in preparing medical devices that require good blood compatibility. In this work, we explore two plasma process techniques, plasma polymerization (PP) and plasma immobilization (PI), to improve the blood compatibility of various polymer and non-polymer surfaces. Thrombus formation and embolization are significant problems for blood-contacting biomedical devices. To minimize these affects, plasma polymerized tetraethylene glycol dimethyl ether (tetraglyme) was deposited on flat Si3N4, and SiO2 samples to produce a PEO-like surface coating. In addition, a microplasma was used to immobilize a Poly(ethylene oxide) (PEO) surfactant to the lumenal surface of PE and PTFE tubing (ID 1.14mm). A microwave-cavity diagnostic was used to measure the plasma density of the microplasma inside of the polymer tube. Emitted light from the plasma during the PP and the PI processes was fed into a monochromator. Coating thickness and chemical composition of the flat surfaces was measured using ellipsometry and XPS, respectively. Contact-angle measurements were made for both the flat PP surfaces and the PI polymer tubes. To test blood compatibility, both the flat PP surfaces and the PI polymer tubes were exposed to heparinized human blood. After blood exposure, the tubes were examined with a scanning electron microscope to assess the density of adhering platelets on the flat PP surfaces and along the length of the PI polymer tubes. The plasma-treated surfaces showed fewer blood adherents than the untreated surfaces. By suitably modifying the plasma parameters, the treatment for both plasma processes can be optimized.