McGowan Institute?
May 2006 | VOL. 5, NO. 5 | www.McGowan.pitt.edu
A tissue-engineered cardiac “patch” promoted both tissue and vessel formation and improved heart function weeks after heart attack, according to researchers who tested the biodegradable material in small-animal studies. Their findings suggest a new therapeutic option for preventing heart failure following myocardial infarction.
“The patch helps keep the tissue thick and mechanically softer, creating a more conducive environment for healing instead of scar tissue formation,” said William Wagner, associate professor of surgery, chemical engineering and bioengineering, and deputy director of the McGowan Institute.
Made of a flexible, microporous polyester urethane material that biodegrades over time, the cardiac patch promoted growth of new vessels and of smooth muscle cell bundles that may aid the contractile function of the heart, the researchers found. By comparison, rats that did not have the patch applied had profound scarring and thinning of the left ventricle wall.
According to Wagner, future studies will determine if seeding the patch with muscle-derived stem cells can bring about even greater improvements in healing and heart function.
The Carnegie Science Center annually recognizes outstanding science and technology achievements. The 2006 recipient of the Life Sciences Award is Savio L-Y. Woo, Ph.D., D.Sc. (Hon.) who is recognized for his work that "has revolutionized the field of orthopedic biomechanics and served as the foundation upon which many patient rehabilitation protocols are currently based for various types of ligament and tendon injury." Dr. Woo is the founder and the director of the Musculoskeletal Research Center.
The McGowan Institute is the 2006 recipient of the Chairman's Award in recognition of the Institute’s work in the "development of therapies that repair or replace damaged organs and tissues resulting in recognition, economic development, saved lives and reduction of health care costs."
The awards were presented at the annual awards ceremony on May 3, 2006 at the Carnegie Museum in Pittsburgh. Awards were presented in the following categories: Advanced Manufacturing & Materials, Catalyst Award, Chairman's Award, Corporate Innovation Award, Elementary Educator Award, Entrepreneur Award, Environmental Award, High School Educator Award, Intermediate Division Student Recognition, Information Technology Award, Junior Division Student Recognition, Life Sciences Award, Media Award, Middle Level Educator Award, Senior Division Student Recognition, School District, Start-up Entrepreneur Award, and University / Post-Secondary Educator Award.
The May 16, 2006 issue of Chemical Science has highlighted the research of Anna Balazs, PhD, Distinguished Professor of Chemical and Petroleum Engineering. Dr. Balazs and her colleagues Alexander Alexeev and Rolf Verberg used computer modeling to simulate the movement of fluid-filled elastic microcapsules over a surface. They say the capsules serve as simple models for biological cells. According to Dr. Balazs, simulating the movement of model biological cells could help predict cell behavior. The interactions between capsules, and whether the capsules will disperse or aggregate, not only depend on the rigidity of the capsules themselves, but also on the nature of the surface on which they are moving.
In the future, Dr. Balazs aims to ‘harness the microcapsules as microreactors to specified locations on a surface in order to carry out certain analyses or enable an exchange of chemicals between the reactors.' The full paper “Modeling the interactions between deformable capsules rolling on a compliant surface” was first published in the web edition of Soft Matter on April 4, 2006.
In a paper presented at the American Geriatrics Society. A study of 401 older adults with an average age of 79 years showed that the variability of their gait can be used as a predictor for later walking disability. Prior studies already have determined that the speed with which an older person walks is a strong predictor for future walking disability.
This study analyzed gait speed, step length, stance time and step width and found that a faster gait speed was associated with a 9 percent lower hazard rate while a longer stance time variability was associated with a 12 percent higher hazard rate. Step length and step width variability were not found to be related to walking disability.
The researchers were Jennifer S. Brach and Jessie Van Swearingen of physical therapy, Anne Newman of epidemiology and medicine and Stephanie Studenski and Subashan Perera of medicine.
Gel May Help Breast Cancer Patients Avoid Radiation Therapy
Women who undergo surgery for breast cancer followed by radiation therapy often experience breast deformities that can only be corrected through reconstructive surgery. McGowan researchers, in collaboration with bioengineers at Carnegie Mellon University, have developed a polymer-based therapy for breast cancer that could serve as an artificial tissue filler after surgery and a clinically effective therapy. “Although radiation therapy is the standard treatment for breast cancer following surgery, it is expensive, time consuming and increases the cosmetic deformity caused by surgery,” said Howard D. Edington, associate professor of surgery and surgical oncology at Pitt and a faculty member at McGowan. “We sought to develop a possible alternative to radiation therapy that would not only release chemotherapy slowly to kill the cancerous cells left behind after surgery but that also would fill in the dimples and sometimes quite significant indentations that are common after breast surgery and radiation.”
Edington said clinical trials on women with breast cancer will follow additional laboratory studies. A paper detailing these results will be published in the Journal of Biomedical Materials Research.
Pitt co-authors of the study were Alicia J. DeFail, Kacey Marra and Wen-Chi C. Lee.
Using a unique combination of mechanical stimulations that accurately mimic the pressure, strain and shear forces to which blood vessels normally are subjected, researchers have demonstrated for the first time that bone marrow-derived progenitor cells can be stimulated to differentiate into mature cells.
One specific type of stimulation, called cyclic pressure, dramatically increased the differentiation of progenitor cells, according to research presented by Timothy M. Maul, a pre-doctoral fellow in bioengineering who is working in the laboratory of Dr. David Vorp.
Why cyclic pressure, which mimics the hydrostatic pressure that causes the stretching of blood vessels, is able to yield greater numbers of differentiated cells is unclear. The researchers plan to look at gene expression patterns for biochemical markers and proteins that are known to influence the way cells behave to get a more accurate picture.
A recent commitment of $350,000 was made to the Department of Bioengineering by Leonard H. Berenfield (BSME ’64) of Cincinnati, Ohio. This multi-year pledge will fully endow a fellowship for a future bioengineering graduate student, preferably one who focuses their research in the area of pediatric cardiovascular devices, a field in which the department already holds a prominent reputation.
Harvey Borovetz, the chair of the bioengineering department, and also a very active pediatric cardiovascular researcher, states that this gift will not only help advance bioengineering research efforts, but will also have a considerable impact on the department’s overall success and reputation, especially in national academic rankings.
“Having this kind of support to attract top students to our program is invaluable. In the current U.S. News & World Report rankings, our graduate program is 15th in the nation overall and 6th among public universities. This confirms our position among the nation’s elite programs. However, it is intensely competitive at this level. Gifts like the Berenfield Fellowship will help keep us among the best.”
The fellowship will further strengthen Pitt’s reputation in the growing field of pediatric cardiovascular devices, according to Borovetz, who also holds a joint appointment in the School of Medicine as the Robert L. Hardesty Professor of Surgery. He currently serves as principal investigator through Pitt’s McGowan Institute for Regenerative Medicine on a five-year, $4.8 million research award from the National Heart, Lung, and Blood Institute to develop a heart-assist device for infants. “With our strong track record in this field and direct links with the medical school, Children’s Hospital and McGowan Institute, future Berenfield Fellows will receive an outstanding educational experience and hopefully contribute to continued advancements in this field.”
The following item is a great synopsis of science based activities in the city of Pittsburgh: As reported in “A Hotbed for Tissue Engineering” by Gregg Ramshaw (PopCity Media), “nearly a thousand of the planet’s brightest minds dedicated to making spare and replacement human body parts gathered in Pittsburgh last month for the Regenerate World Congress on Tissue Engineering and Regenerative Medicine at the Westin Convention Center downtown.
Some 850 biotech engineers, scientists, students, physicians, and entrepreneurs attended the convention, nearly a third of them representing 40 nations and five continents. More than 500 research papers, lectures, and poster presentations were delivered over the course of four days. Participants discussed mind-boggling and highly-sophisticated advancements, both large and small, in their scientific universe of helping the human body repair itself. A veritable melting pot of scientists cruised the corridors, many conversing animatedly in their native tongues.
In addition, the annual meeting of the Society for Biomaterials followed the Regenerate Congress, bringing another 1,000 participants to Pittsburgh. The Congress and the Society overlapped one day so that concurrent sessions of mutual interest could be held”.
See the coverage of the state-of-the art of drug discovery in the May issue of PittMed. Ivet Bahar shares her insight and the vision of the future in this important area. The opportunities exist to move from the discovery of drugs through trial and error. Dr. Bahar notes that “there are libraries of compounds that are screened against proteins to see which ones produce an effect.” A more rational—and effective—approach, she suggests, would allow researchers to identify optimal drug candidates in advance of experimentation, anticipating the molecular reactions they might initiate. Such capacity would save vast quantities of time and money. But that means understanding both the rate at which any given reaction will proceed and how the structure of a particular enzyme influences its interactions.
The Strick Lab is using viruses as tracers to map the intricate circuitry and architecture of the nervous system. Dr. Strick and his colleagues have found that the basal ganglia play a part in the realms of vision, affect, sensation, higher executive processing, and, as long understood, motor control. If the ganglia aren’t functioning properly, the result can be Tourette’s syndrome, attention deficit hyperactivity disorder, obsessive compulsive disorder, Huntington’s disease, or Parkinson’s disease. The basal ganglia, Strick has made clear, have something to do with our behavior and our ability to control our actions.
Dr. Strick and his colleagues continue to search for the answers are hidden in those deep dark basements of gray matter—what some might call the physical reality of the brain.
The Regenerative Medicine Podcasts continue to be well received. There have been over 1,500 downloads to date. The most recent podcasts are:
| Patrick E. Crago, PhD, is the Allen H. and Constance T. Ford Professor and chairman of the Department of Biomedical Engineering at Case Western Reserve University. |
Savio L-Y. Woo, Ph.D., D.Sc. is the W.K. Whiteford Professor, Department of Bioengineering, and Professor-Mechanical Engineering, and Professor-Rehabilitation Science & Technology, University of Pittsburgh. Dr. Woo is also Vice Chairman for Research, Mentorship/Internship Program, Department of Bioengineering. |
Visit www.regenerativemedicinetoday.com to keep abreast of the new interviews.
Publication of the Month
Publication of the Month | May 2006 |
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| Author(s) | Todd Courtney, Michael S. Sacks, John Stankus, Jianjun Guan, William R. Wagner |
| Title | Design and analysis of tissue engineering scaffolds that mimic soft tissue mechanical anisotropy |
| Summary | Tissue engineered constructs must exhibit tissue-like functional properties, including mechanical behavior comparable to the native tissues they are intended to replace. Moreover, the ability to reversibly undergo large strains can help to promote and guide tissue growth. Electrospun poly (ester urethane) ureas (ES-PEUU) are elastomeric and allow for the control of fiber diameter, porosity, and degradation rate. ES-PEUU scaffolds can be fabricated to have a well-aligned fiber network, which is important for applications involving mechanically anisotropic soft tissues. We have developed ES-PEUU scaffolds under variable speed conditions and modeled the effects of fiber orientation on the macro-mechanical properties of the scaffold. To illustrate the ability to simulate native tissue mechanical behavior, we demonstrated that the high velocity spun scaffolds exhibited highly anisotropic mechanical properties closely resembling the native pulmonary heart valve leaflet. Moreover, use of the present fiber-level structural constitutive model allows for the determination of electrospinning conditions to tailor ES-PEUU scaffolds for specific soft tissue applications. The results of this study will help to provide the basis for rationally designed mechanically anisotropic soft tissue engineered implants. |
| Source | Biomaterials, Volume 27, Issue 19, July 2006, Pages 3631-3638 |
Grant of the Month
Grant of the Month | May 2006 |
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| PI | Harvey S. Borovetz, PhD |
| Title | Pediatric Circulatory Support |
| Description | The PediaFlow™ is a miniature magnetically levitated turbodynamic VAD for pediatric patients ranging from birth weight to 15 kg. Our design is based on extensive computational modeling. CFD analysis was used to optimize the flow field for efficiency and hemocompatibility and reach a design point of 0.5 L/min at a 110 mm Hg pressure head. |
| Source | NIH (HHSN268200448192C) |
| Term | 02/15/04 – 03/29/09 |