SURFACE CHARACTERISTICS OF IMPLANTABLE LONG-TERM USE FONTAN PUMP MATERIALS

Open Access
Author:
Mc Hugh, Clare Moire
Area of Honors:
Biomedical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Keefe B Manning, Thesis Supervisor
  • Justin Lee Brown, Honors Advisor
Keywords:
  • Biomaterials
  • Biomedical Engineering
  • Fontan Circulation
  • Fluid Mechanics
  • Biocompatibility
  • Platelet Adhesion
  • Thrombosis
  • Medical Device
Abstract:
Penn State Hershey Medical Center is developing a small implantable pump for long-term mechanical support of patients with a failing Fontan circulation. An increasing number of patients who undergo the Fontan operation are surviving to adulthood and require a device to provide sustained support. Many blood contacting components of this pump are manufactured from polyetheretherketone (PEEK), which has not been thoroughly characterized with regards to its biocompatibility. This study analyzes the surface characteristics of PEEK and compares them to previously characterized pediatric pump polyurethane materials to analyze their thrombosis potential. Prior to analyzing platelet adhesion, the material surfaces of PEEK and polyurethane are studied using optical profilometry and x-ray photoelectron spectroscopy. An established rotating disk system protocol is used to test the adhesion of bovine platelets to the material surfaces at varying shear rates. The samples are analyzed with scanning electron microscopy and confocal microscopy. The samples prepared for confocal microscopy are stained, and these immunofluorescently labeled samples are imaged with a 20x dry objective to quantify the number of adhered platelets at different radial positions on the sample. Using platelet counts obtained from the confocal microscopy, the overall platelet adhesion for each of the PEEK and polyurethane samples was determined by calculating an adhesion coefficient. Overall trends in adhesion coefficient behavior showed the values decreased at higher shear rates. Material characterization techniques revealed consistent trends in platelet behavior across the different material samples.