Spring 2007 Newsletter

The Mechanical Stimulation of Bone Marrow-Derived Progenitor Cells

Under the guidance of David Vorp, associate professor of bioengineering and surgery, Timothy Maul was awarded a Cellular Approaches to Tissue Engineering and Regeneration (CATER) predoctoral fellowship through the McGowan Institute for Regenerative Medicine (MIRM) as well as the American Heart Association and Ruth L. Kirschstein National Research Service Award (NIH F31) predoctoral fellowships. More recently, Maul (pictured at left with Vorp), was awarded the Pennsylvania Association of Graduate Schools’ Outstanding Graduate Student Award. Maul’s F31 grant from the National Institutes of Health, titled “Influence of Mechanical Forces on Adult Progenitor Cells,” aims to investigate bone marrow derived progenitor cells.

Project Goals

Most of the work performed on bone marrow-derived progenitor cells (BMPCs) to date has investigated their differentiation under chemical stimuli, but in vivo environments may not provide these cytokines in levels used to elicit the desired response. Instead, BMPCs might rely on in vivo mechanical signals for maintenance of their phenotype. Based on the applicant’s preliminary data, the goal of this project is to determine the differentiation potential of rat BMPCs toward vascular cells under three physiologically relevant mechanical stimuli; namely, shear stress, cyclic stretch, and cyclic hydrostatic pressure.

To that end, we propose two specific aims: (1) to elucidate the dose-dependent response of BMPCs to varying magnitudes and frequencies of each separate mechanical force stimulus; i.e., shear stress, cyclic stretch, and cyclic hydrostatic pressure; (2) to elucidate the temporal response of BMPCs to the most appropriate frequency and magnitude determined from Specific Aim 1 for each mechanical force stimulus. The endpoints that will be evaluated are vascular smooth muscle cell- and endothelial cell-specific protein expression, functional indicators for both of these cell types, cell viability, and basic morphology.

About Tim

Timothy Maul is currently completing his PhD in bioengineering with concentrations in vascular biology, biomechanics, and tissue engineering. He also completed a BS in bioengineering here at Pitt, graduating magna cum laude with a University Honors Scholarship.

Maul is conducting his graduate research in Vorp’s lab, where he is studying the isolation, characterization, and differentiation of human adult progenitor cells derived from the bone marrow and the mechanical stimulation of bone marrow-derived progenitor cells. Maul says, “My research training under the direction of David Vorp has opened a world of possibilities in the exciting and rapidly developing realm of tissue engineering. Vorp has been a tremendous mentor and has worked closely with me throughout my studies. Our work has generated many conference abstracts and presentations, peer-reviewed publications, and review articles.”

The ECMO program

For the past five years, Maul has been an extracorporeal membrane oxygenator (ECMO) technician for the Children’s Hospital of Pittsburgh. ECMO is a heart-lung bypass technology that is used to provide advanced life support for heart and lung function. Maul says, “Through the ECMO program, I have participated at the front lines in the care of infants and children with cardiac and pulmonary disease who require this extraordinary support.” As a technician, he has operated and conducted troubleshooting on equipment, recorded patient vital signs, performed anticoagulation tests, administered medications and blood products, and interacted with the nurses and physicians to provide the highest level of care for these patients in the intensive care unit.

In addition to the basic responsibilities of a technician, Maul’s role for ECMO has been elevated to that of a specialist, “where I am charged with being on call to assist the surgeons in placing a patient on the machine,” he says. “It is truly a unique experience that I believe every bioengineer should have the opportunity to share in, because it has demonstrated to me where the technology and research can and should be applied, and has fostered many new ideas in my mind for my future research. My experiences at Children’s have been intertwined in my education through the bioengineering ethics course, where I have been a guest lecturer on the topic of advanced life support and the ethical responsibilities of the bioengineer.”

Pitt’s relationship with UPMC

Maul believes that the close relationship between the Department of Bioengineering at the University of Pittsburgh with the University of Pittsburgh Medical Center (UPMC) and University of Pittsburgh School of Medicine has increased his opportunities and enhanced his experiences throughout his education. Recently, he produced a training video that describes the unique relationship between the Department of Bioengineering and the surrounding hospitals and showcases these experiences available to bioengineers. This video is available on the Department of Bioengineering Web site.

Read About another Outstanding Graduate Researcher

Graduate student Scott VanEpps also received an F31 grant. Read “Coronary Arterial Dynamics and Atherogenesis.”

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