Joel L. Berry, PhD

Joel L. Berry, Ph.D., Research Assistant Professor

Dr. Berry was born and raised in Birmingham, Alabama. He received his Bachelor's Degrees in biology (1985) and mechanical engineering (1989) and Master's in mechanical engineering (1992) from the University of Alabama at Birmingham. After several years as a staff mechanical engineer in the Biomechanics Laboratory at UAB, the Ecole Polytechnique Federale de Lausanne in Switzerland, and the Department of Radiology at Wake Forest School of Medicine, Dr. Berry obtained his Ph.D. in biomedical engineering from Wake Forest in 2001. He has devoted his research to the biomechanics of blood flow and stress in vessel walls, particularly diseased vessels treated with vascular stents. Dr. Berry joined the Wake Forest Institute for Regenerative Medicine with a cross-appointment in 2004 and is developing bioreactors for tissue engineered arteries and tissue engineered heart valves. He is currently an Assistant Professor in the Department of Biomedical Engineering and is cross-appointed to the Wake Forest Institute for Regenerative Medicine. Dr. Berry is the author of several papers and has received 4 vascular stent patents.

SYNOPSIS OF AREA OF INTEREST: Blood flow in arteries, arterial wall stress, platelet attachment to vascular prostheses, vascular stent design, bioreactor design, vascular CT and MR imaging, signal processing, orthopedic device design, finite element analysis

DETAILED AREA OF INTEREST:

Vascular Stents : Dr. Berry has been investigating the fluid mechanical and solid mechanical consequences of vascular stenting. In vitro measurement tools such as dye injection visualization and digital particle image velocimetry reveal disturbances in physiologic flow that may lead to thrombotic responses in stents. This has been confirmed with computational fluid dynamic analyses. Finite element analyses have shown that stents elevate vessel wall stress significantly beyond physiologic stress. This excessively high stress that is cycled at every heartbeat may lead to tissue proliferation within the stent. Several stent designs have been proposed by our laboratory to alleviate this effect. Preliminary in vivo studies in our laboratory have demonstrated that matching the compliance at the junction of stented and unstented vessel has the effect of minimizing the vessel response compared to non-compliance matched stents.

Platelet Attachment Force to Surfaces: Atomic force microscopy has been used to measure the force of platelet attachment to biological surfaces in aqueous solution. Ongoing studies in our collaborating laboratories will demonstrate that platelets bind to different surfaces with different binding affinities. Of particular interest is the platelet binding force to anti-adhesins.

Development of Recombinant DNA Anti-Adhesins: Dr. Berry is currently testing a recombinant DNA variant of the plasma protein vitronectin as an anti-adhesive protein coating for implantable vascular devices. Preliminary results have shown this protein to be highly adherent to metallic surfaces and extremely effective at limiting thrombus formation on stents as well reducing neointimal hyperplasia.

Development of Bioengineered Arterial Grafts and Heart Valves: He is currently collaborating with the Wake Forest Institute for Regenerative Medicine to develop efficient bioreactors to precondition cell-seeded arterial scaffolds before implantation as arterial replacements or heart valves.