What's Happening At The
McGowan Institute?

December 2008 | VOL. 7, NO. 12 | www.McGowan.pitt.edu

Dr. Sacks Named 2009 Recipient of the ASME Van C. Mow Medal

Dr. Michael Sacks, McGowan Institute faculty memberMcGowan Institute for Regenerative Medicine faculty member Michael Sacks, PhD, the William Kepler Whiteford Professor, Department of Bioengineering, University of Pittsburgh, has been named the 2009 recipient of the American Society of Mechanical Engineers (ASME) Van C. Mow Medal. Dr. Sacks was selected to receive this prestigious honor for his contributions in advancing biomechanics of native and engineered heart valve tissues. The Van C. Mow Medal, established in 2004, is bestowed upon an individual who has demonstrated meritorious contributions to the field of bioengineering through research, education, professional development, leadership in the development of the profession, mentorship to young bioengineers, and with service to the bioengineering community.

"The University of Pittsburgh Department of Bioengineering extends our heartiest congratulations to Professor Sacks on this wonderful award in recognition of his career accomplishments in and leadership to our profession," said Harvey Borovetz, PhD, Pitt’s Bioengineering Department Chair and Deputy Director, Artificial Organs and Medical Devices at the McGowan Institute.

Dr. Sacks’ overall research focus is quantification and modeling of the structure-mechanical properties of native and engineered soft tissues, with a focus on tissues of the cardiovascular and urological systems. In particular, his laboratory has focused on the mechanical behavior and function of the native aortic and mitral heart valves, including the development of the first constitutive (stress-strain) models for these tissues using a structural approach. His laboratory is also active in the biomechanics of engineered tissues, and in particular understanding the in-vitro and in-vivo remodeling processes from a functional biomechanical perspective.

Formal presentation of the award to Dr. Sacks is scheduled to take place at the 2009 Summer Bioengineering Conference, June 17-21, 2009, at the Squaw Creek Resort, Lake Tahoe, California.

Congratulations, Dr. Sacks!

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William G. McGowan Charitable Fund Supports Cardiac Research

McGowan faculty member, Dr. Peter Wearden The McGowan Institute for Regenerative Medicine recently received $750,000 toward research efforts in the development of regenerative medicine therapies for cardiac failure from the William G. McGowan Charitable Fund.  The grant is aimed at improving survival rates in patients with heart failure. The focus of the McGowan Institute is on the development of new regenerative medicine-based therapies and the rapid translation of these emerging technologies to clinical assessment and use.

Proceeds from the grant will support research that is addressing the development of mechanical circulatory support technology for infants and children.  The success with ventricular assist devices (VADs) as bridges to transplant or as bridges to recovery is widely recognized for adult cardiac patients.  However, the pediatric sector for such therapies has been largely ignored until recently. Under the leadership of McGowan Institute physician/scientist Peter Wearden, MD, PhD and his colleagues, some dramatic progress is being made in the pediatric cardiac care sector.  This research team is focusing on the development of miniaturized VADs.

The McGowan Charitable Fund was established to realize -- and to enlarge -- the magnificent potentials which Mr. McGowan foresaw in the future of the young, as well as the rewarding promises of medical research, and the critical need to enhance the role of American business by providing scholastic assistance to promising students. 

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McGowan Institute Retreat: Register Now

Nemacolin Woodlands Resort The 8th Annual McGowan Institute for Regenerative Medicine Scientific Retreat is set to take place on March 9-11, 2009 at Nemacolin Woodlands Resort.  An informal mixer will occur on the evening of March 8, 2009. 

Under the leadership of Dr. William Wagner, the program committee is planning an exciting group of speakers and topics.  The program will include distinguished guest speakers, a poster session, and potential external partners and collaborators, so there will be multiple opportunities for networking and collaboration.  The registration deadline is February 15, 2009 (or sooner; no reservations will be accepted once the reservation quota is filled.)

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Injured Heart Muscle Repaired in Laboratory Tests of Novel Stem Cell

Dr. Johnny Huard, McGowan Institute faculty memberA research team – led by McGowan Institute for Regenerative Medicine faculty member Johnny Huard, PhD – has been able to effectively repair damaged heart muscle in an animal model using a novel population of stem cells they derived from human skeletal muscle tissue. The researchers at Children’s Hospital of Pittsburgh of UPMC transplanted stem cells purified from human muscle-derived blood vessels into the hearts of mice that had heart damage similar to that which would occur in people who had suffered a heart attack.

These transplanted myoendothelial cells repaired the injured muscle, stimulated the growth of new blood vessels in the heart, and reduced scar tissue from the injury, thereby dramatically improving the function of the injured left ventricle, said Dr. Huard, director of the Stem Cell Research Center at Children’s Hospital’s John G. Rangos Sr. Research Center “This study confirms our belief that this novel population of stem cells discovered in our laboratory holds tremendous promise for the future of regenerative medicine. Specifically, myoendothelial cells show potential as a therapy for people who have suffered a myocardial infarction,” said Dr. Huard, also the Henry J. Mankin Professor and vice chair for research in the Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine. “The important benefit of our approach is that as a therapy, it would be an autologous transplant. This means that for a patient who suffers a heart attack, we would take a muscle biopsy from his or her muscle, isolate and purify the myoendothelial cells, and re-inject them into the injured heart muscle, thereby avoiding any risk of rejection by introducing foreign cells.”

The myoendothelial cells used in this study were more effective at repairing the injured cardiac muscle and reducing scar tissue than previous approaches that have used muscle cells known as myoblasts, according to Dr. Huard. At 6 weeks after injection, the myoendothelial cell-injected hearts functioned at 40 to 50 percent more effectively compared with hearts that had been injected with myogenic cells (myoblasts).

Dr. Huard and colleagues in the Stem Cell Research Center are researching and developing numerous therapeutic uses for the population of muscle stem cells the team identified. One of the most promising uses could be for the treatment of Duchenne muscular dystrophy (DMD), a genetic disease that affects 1 in every 3,500 boys. Patients with DMD lack dystrophin, a protein that gives muscle cells structure.

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Dr. George Michalopoulos Inducted as a Fellow into AAAS

McGowan faculty member Dr. George MichalopoulosMcGowan Institute faculty member George K. Michalopoulos, MD, PhD was recently inducted as a fellow into the American Association for the Advancement of Science (AAAS).  AAAS is an international non-profit organization dedicated to advancing science around the world by serving as an educator, leader, spokesperson and professional association.  The tradition of AAAS fellowship began in 1874 and is an honor bestowed upon AAAS members by their peers.   Dr. Michalopoulos was elected as an AAAS fellow as part of the Section on Medical Sciences for his outstanding contributions to understanding the pathways of growth factors that lead the liver to regenerate.

Dr. Michalopoulos is the Maud L. Menten Professor and Chair of Pathology at the University of Pittsburgh School of Medicine.  He has previously won the National Institutes of Health Merit Award, and he has authored over 200 peer-reviewed publications.

Congratulations, Dr. Michalopoulos!

Robotic Probe Technology Headed for Clinical Surgical Use

McGowan faculty member Dr. Marco Zenati In 2005, McGowan Institute for Regenerative Medicine faculty member Marco Zenati, MD, a University of Pittsburgh School of Medicine professor of surgery and biomedical engineering, and Howie Choset, PhD, a Carnegie Mellon University robotics professor, co-founded Cardiorobotics Inc. -- among the most successful of the 42 start-up companies spun off from University of Pittsburgh research since 2003.  Through Cardiorobotics, Drs. Zenati and Choset have created a system that enables a tiny robot to enter the body through a 10-millimeter hole during surgery.

The central element of their technology is a teleoperated probe consisting of a series of links.  The probe is highly flexible and thus either assumes the shape of its surroundings or can be reshaped.  The probe “remembers” its previous configurations as it moves through a three-dimensional volume.  The links of the probe can be made out of almost any material, including plastic, allowing it to be “disposable.”  A working channel or lumen, allows tools to pass through the probe and perform various procedures. This teleoperated, highly articulated probe with a non-linear lumen is called an Articulated Robotic MedProbe or ARM™.  Plans for ARM™ include minimally invasive cardiac surgery and laparoscopic and gastro-intestinal procedures. 

"We're looking at using the technology with humans in the next 6 to 12 months," Dr. Zenati said.

The clinical benefits to patients are profound when an “open” procedure can be made minimally invasive.  By definition, performing any procedure less invasively results in less soft tissue disruption, with the effects of reduced pain, faster healing and recovery, and fewer complications.  Documented advantages of less invasive procedures include smaller incisions and fewer injuries to major blood vessels and nerves.  Other benefits reported include, reduced blood loss and decreased post-operative pain, and shorter hospital stays and faster return to normal activity for the patient.  Further, despite the higher capital expense of equipment needed to operate in a minimally-invasive fashion, overall costs of minimally-invasive procedures can be significantly lower.

Dr. Zenati is also Director of the Center for Minimally Invasive Cardiac Surgery and Robotics at the University of Pittsburgh Medical Center, Chief of the Division of Cardiac Surgery at the VA Pittsburgh HealthCare System, Adjunct Faculty at the Robotics Institute and Adjunct Associate Professor of BioMedical Engineering both at Carnegie Mellon University.  Dr. Zenati performed the first U.S. robotic beating-heart coronary artery bypass surgery in 2000.

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New Guidelines Released for Stem Cell Research

McGowan faculty member Dr. Ira FoxMcGowan Institute for Regenerative Medicine faculty member Ira J. Fox, MD, Director of the Center for Innovative Pediatric Regenerative Therapies, a joint program of the University of Pittsburgh School of Medicine’s Department of Surgery, the McGowan Institute, and Children’s Hospital of Pittsburgh of UPMC, is co-author of the new guidelines for the responsible development of safe and effective stem cell therapies for patients.  The guidelines were released by the International Society for Stem Cell Research (ISSCR), the world’s leading professional organization of stem cell researchers. 

The guidelines define a roadmap for medical researchers and doctors, outlining what needs to be accomplished to move stem cells from promising research to proven treatments for patients. The new guidelines will accelerate the translation of stem cell research into practice while addressing associated scientific, clinical, regulatory, ethical, and social issues. Founded on core principles of scientific rigor and ethical conduct, the recommendations offered in the guidelines include an insistence on expert evaluation and independent oversight, a thorough informed consent process to provide patients with essential information on the unique aspects of stem cell-based treatments, and transparency in reporting of clinical trial results.

"We don't want to slow the field down," said Dr. Fox. "But we want to make sure that it is safe and careful and ethical."

Too often rogue clinics around the world exploit patients’ hopes by offering unproven stem cell therapies, typically for large sums of money and without credible scientific rationale, oversight, or patient protections. The ISSCR’s new guidelines establish standards that can be used to judge the claims made by stem cell clinics and whether the treatments they offer are being developed responsibly. The ISSCR also offers a handbook for patients and their doctors evaluating a stem cell therapy.

The ISSCR urges governments and regulatory bodies to enact the recommendations outlined in these guidelines. The guidelines call for countries without an official regulatory body to develop a way to monitor new stem cell-based treatments, and the ISSCR has offered to advise agencies that want to build these regulatory capacities.

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ISSCR

Pittsburgh Tribune Review

Children’s Transplant Department Partners with The Children's Home of Pittsburgh & Lemieux Family Center

McGowan faculty member Dr. George Mazariegos“As soon as I walked in the door, I said our patients have to come here as soon as possible," said McGowan Institute for Regenerative Medicine faculty member George Mazariegos, MD, director of pediatric transplantation in the Hillman Center for Pediatric Transplantation at Children's Hospital of Pittsburgh of UPMC.  Without The Children's Home of Pittsburgh & Lemieux Family Center, transplant patients would have to stay longer at Children's or transfer to local hospitals that might not be able to assume very quickly the high level of medical care necessary following a transplant, he said.

The Children's Home of Pittsburgh & Lemieux Family Center, established in 1893, is an independent, non-profit licensed organization that promotes the health and well-being of infants and children through services which establish and strengthen the family.  It includes a 28-bed Pediatric Specialty Hospital - infant and pediatric units that provide short-term transitional care from hospital to home for those who are technology dependent and who may suffer from life threatening illnesses. The Pediatric Specialty Hospital offers a nurturing, home-like environment while empowering caregivers to become competent and confident in caring for their children.  Its family-focused philosophy teaches families how to manage the needs of their medically fragile child and helps both parents and siblings adjust to new roles and responsibilities.

“I think the advantages [of the home] are it allows for increased patient and family interaction because the facility is set up to do that. Their staff is the same as it is at Children's Hospital and it allows continuity of care. It also frees up the acute hospital beds for kids more acute at Children's as well,” said Dr. Mazariegos.

Dr. Mazariegos is an active pediatric liver and intestinal transplant surgeon. His main clinical interests are focused on the care of pediatric patients who have liver and/or intestinal disease requiring transplantation. He also specializes on treatment of adult and pediatric patients who develop acute liver failure and who may require specialized liver support therapies until they recover or until donor organs are available.

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Keeping Herpes Infection in Check

McGowan faculty members from top: Dr. Robert HendricksMcGowan Institute for Regenerative Medicine faculty member Robert L. Hendricks, PhD, Joseph F. Novak professor and vice-chair for research in the Department of Ophthalmology and professor in the Departments of Immunology and Microbiology and Molecular Genetics at the University of Pittsburgh School of Medicine, and colleagues challenge the once common notion that latent herpes simplex virus type I (HSV-1) in sensory neurons is invisible to the immune system.  HSV-1 can cause bouts of cold sores, blindness, and potentially lethal encephalitis when it reawakens from a quiescent state in the nerve cells it infects.  To prevent these consequences, the stealthy virus is kept under constant guard by the immune system, actively holding HSV-1 in check without destroying the neurons harboring it, said Dr. Hendricks.  Sensory neurons may not regenerate, so an immune system attack that destroys them could do more harm than good.

In a paper recently published, teams led by Dr. Hendricks and Paul R. Kinchington, Ph.D., also a professor in the University of Pittsburgh School of Medicine Department of Ophthalmology, show one way this balancing act is carried out.  Immune cells called CD8 T cells attack virus-infected cells with lytic granules, which are packets of potentially toxic enzymes. Transport of lytic granule contents into infected cells typically initiates a process that leads to a form of cellular suicide called apoptosis.  However, according to the researchers’ experiments, that isn’t the case when CD8 T cells target infected sensory neurons.

Dr. Hendricks noted that up to 90 percent of people eventually become infected with HSV-1, many in childhood. The initial infection typically produces mild symptoms or none at all, but the virus remains in the neurons for a lifetime, occasionally waking up to cause disease. It repeatedly scars the cornea when this occurs in the eye, making HSV-1 a leading infectious cause of blindness. 

Previous studies showed CD8 T cells can use interferon-gamma to block reactivation without killing the neuron, but only some sets of neurons are controlled in this manner, Dr. Hendricks said. His team will continue to try to identify how immune cells, HSV-1, and neurons interact, which could have implications for treatment and vaccine development for HSV-1 infections, as well as for gene therapy applications that use harmless versions of the herpes virus as a vector to ferry treatment genes into cells.

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Arsenic in Drinking Water May Increase Risks For Cardiovascular Disease

McGowan faculty member Dr. Donna StolzMcGowan Institute for Regenerative Medicine faculty member Donna Stolz, PhD, Assistant Director of the Center for Biologic Imaging and Research Assistant Professor in the Department of Cell Biology and Physiology at the University of Pittsburgh, along with a team of Pitt researchers found that when mice are exposed to arsenic at federally-approved levels for drinking water, pores in liver blood vessels close, potentially leading to cardiovascular disease.  The study, while preliminary, also reveals how an enzyme linked to hypertension and atherosclerosis alters cells, and may call into question current Environmental Protection Agency (EPA) standards that are based solely on risks for cancer. 

In the study, the research team looked at specialized cells in the liver called sinusoidal endothelial cells, which are tasked with removing wastes from blood and enabling nutrients to regulate metabolism. After exposing mice to 10 to 100 parts per billion (ppb) of arsenic over a 2-week period, the cells were less able to remove damaged proteins from the blood and lost their characteristic pores or “windows,” severely compromising the cells’ ability to effectively exchange nutrients and waste.  Aaron Barchowsky, PhD, team lead and associate professor of environmental and occupational health at the University of Pittsburgh Graduate School of Public Health, notes that despite their small size, mice are usually less sensitive to the effects of arsenic than people

The current EPA standard for arsenic in public water systems is 10 ppb, reduced from 50 ppb in 2006. The standard applies only to drinking water sources that serve more than 20 people. 

According to the research, arsenic increased the activity of an enzyme called NADPH oxidase and the levels of oxidants it produces, compromising sinusoidal cell functions. Mice that lacked the enzyme did not have changes in liver blood vessels when exposed to arsenic and their cells were able to continue to function effectively.

Next phases of the research will focus on further understanding how arsenic increases the production of oxidants by NADPH oxidase and determining effective preventative measures to lessen the impact of arsenic and other environmental exposures on the function of the endothelial cells. Additional studies will investigate the relationship between arsenic’s effects on liver blood vessels and metabolism and disease-related changes in other blood vessels in the body.

Arsenic is a naturally occurring mineral primarily found in groundwater. Drinking high levels of arsenic over many years has been linked to increased risks for lung, bladder, and skin cancers, as well as heart disease, diabetes, and neurological damage.

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McGowan Faculty Member Elected SMDM President

McGowan Institute faculty member Dr. Mark Roberts McGowan Institute for Regenerative Medicine faculty member Mark S. Roberts, MD, MPP, FACP was sworn in as president of the Society for Medical Decision Making (SMDM) during the organization’s annual meeting in October.  SMDM has over 1000 members, including trainees and senior researchers as well as educators, clinicians, managers, and policy makers.  Its mission is to improve health outcomes through the advancement of proactive systematic approaches to clinical decision making and policy-formation in health care by providing a scholarly forum that connects and educates researchers, providers, policy-makers, and the public.

Dr. Roberts is a professor of Medicine, Health Policy and Management, and Industrial Engineering at the University of Pittsburgh.  He is also a Senior Associate and Charter Member of the Center for Biomedical Informatics as well as the Chief of the Section of Decision Sciences and Clinical Systems Modeling, Division of General Internal Medicine, University of Pittsburgh School of Medicine.  He has written over 100 refereed articles.  His research interests include decision analysis methodology, medical information systems, health care policy, and health economics.

Congratulations, Dr. Roberts!

Telerehabilitation Focus of Recent Virtual Conference

McGowan faculty member Dr. David BrienzaMcGowan Institute for Regenerative Medicine faculty member David M. Brienza, PhD, and the Rehabilitation Engineering Research Center (RERC) on Telerehabilitation at the University of Pittsburgh's School of Health and Rehabilitation Sciences welcomed health and rehabilitation professionals and industry partners, government agency representatives, and consumers to attend the Virtual State-of-the-Science Conference on Telerehabilitation. Dr. Brienza, professor in the Department of Rehabilitation Science and Technology (RST), served as the conference co-director.  The conference, free of charge and offered entirely online, was held from 1 to 4 p.m. each day from Monday, November 17 through Thursday, November 20.

Telerehabilitation serves people with disabilities by researching and developing methods, systems, and technologies that support remote delivery of rehabilitation and home health care services for individuals who have limited local access to comprehensive medical rehabilitation outpatient and community-based services. This conference held live, interactive sessions on current issues related to telerehabilitation, including clinical and research applications, accessibility and usability, and policy issues.

Michael McCue, PhD, vice chair and associate professor, RST, and director of the Rehab Counseling Program, was a conference co-director along with Dr. Brienza. The RERC on Telerehabilitation was supported by a grant from the U.S. National Institute on Disability and Rehabilitation Research

Laryngitis: No Laughing Matter

McGowan faculty member Dr. Clark Rosen McGowan Institute for Regenerative Medicine faculty member Clark A. Rosen, MD, is director of the UPMC Voice Center and associate professor of otolaryngology, University of Pittsburgh School of Medicine.  Dr. Rosen specializes in the treatment and research of voice disorders.  One voice disorder, viral laryngitis (inflammation of the voice box), occurs as a result of a viral infection of the larynx. Viruses usually are contracted by inhaling respiratory droplets released into the air by people who are "carrying" the virus.

"It's tough to prevent getting a viral infection, shorten it, or get rid of it," said Dr. Rosen. "We have to learn how to live with it and minimize the impact of viral infections to the throat."

The most common patient complaint of laryngitis is hoarseness. Hoarseness is usually a raspy or husky sound of the voice resulting from swelling within the vocal fold. Swelling limits the normal vibratory movement of the vocal fold during phonation, which causes the sound produced to be less harmonic and raspier.  If there is significant swelling of the vocal folds, they may not be able to vibrate at all, and no sound or only a whisper is produced. 

The voice should not be used excessively during laryngitis in the absence of evaluation by an ear-nose-throat (ENT) specialist (otolaryngologist). In some cases of laryngitis, excessive voice use can cause further and irrevocable injury to the vocal folds, leading to vocal fold hemorrhage, vocal fold scar, and/or vocal fold lesions. Examples of excessive voice use include singing, acting, performing, lecturing, or excessive talking or phone use.

"People keep using or abusing their voice while they're sick," Dr. Rosen said. "The vocal folds are much more prone to permanent injury [polyps, cysts, scar tissue] when they're swollen."

Hydration is an important component of laryngitis treatment. In most cases of laryngitis, either the mucous secretions are excessively thick or the lubrication of the larynx is decreased. Drinking water helps to maintain the thin character of the mucosal lubrication. Steam or mist humidifiers can help to lubricate the vocal folds. Avoiding exposure to drying agents such as caffeine or dehydrating medications can also help to preserve the lubrication of the larynx. Limiting voice use allows the vocal fold tissue to heal without the added trauma and stress caused by trying to phonate with swollen vocal folds. Voice rest can help to accelerate the healing process.

If left untreated, laryngitis is thought by some physicians to lead to the development of hyperfunctional voice disorders such as muscle tension dysphonia, which may contribute to the formation of nodules, polyps, cysts, scarring, hyperkeratosis, and Reinke's edema.

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News:Laryngitis: No Laughing Matter - Regenerative Medicine at the McGowan Institute


Regenerative Medicine Podcast Update

The Regenerative Medicine Podcasts continue to gain listeners and explore pertinent topics. Remember to tune in and keep abreast of new interviews. The most recent podcasts are:

#60 – David Whitcomb, MD – Dr. Whitcomb is Professor of Medicine, Cell Biology and Physiology, and Human Genetics at the University of Pittsburgh. Additionally, he is the Chief of the Division of Gastroenterology, Hepatology, and Nutrition, as well as the founder and Director of the Center for Genomic Sciences.  He discusses the research of his Division that is pioneering alternative diagnosis and treatment for disorders of the pancreas, liver and the intestine.

#61 – John Pollock – Dr. Pollock is an Associate Professor at Duquesne University, Bayer School of Natural Sciences and Environment. Dr. Pollock shares highlights of his scientific studies on the mechanisms of pain generation and possible techniques for improved pain management.  He also describes the videos that he and his team produce to educate the general public and students on tissue engineering and regenerative medicine.

Visit www.regenerativemedicinetoday.com to keep abreast of the new interviews.

Publication of the Month
Authors:

Engelmayr GC Jr, Soletti L, Vigmostad SC, Budilarto SG, Federspiel WJ, Chandran KB, Vorp DA, Sacks MS.

Title:

A novel flex-stretch-flow bioreactor for the study of engineered heart valve tissue mechanobiology.

Summary:

Tissue engineered heart valves (TEHV) have been observed to respond to mechanical conditioning in vitro by expression of activated myofibroblast phenotypes followed by improvements in tissue maturation. In separate studies, cyclic flexure, stretch, and flow (FSF) have been demonstrated to exhibit both independent and coupled stimulatory effects. Synthesis of these observations into a rational framework for TEHV mechanical conditioning has been limited, however, due to the functional complexity of tri-leaflet valves and the inherent differences of separate bioreactor systems.

Toward quantifying the effects of individual mechanical stimuli similar to those that occur during normal valve function, a novel bioreactor was developed in which FSF mechanical stimuli can be applied to engineered heart valve tissues independently or in combination. The FSF bioreactor consists of two identically equipped chambers, each having the capacity to hold up to 12 rectangular tissue specimens (25 x 7.5 x 1 mm) via a novel "spiral-bound" technique. Specimens can be subjected to changes-in-curvature up to 50 mm(-1) and uniaxial tensile strains up to 75%. Steady laminar flow can be applied by a magnetically coupled paddlewheel system. Computational fluid dynamic (CFD) simulations were conducted and experimentally validated by particle image velocimetry (PIV). Tissue specimen wall shear stress profiles were predicted as a function of paddlewheel speed, culture medium viscosity, and the quasi-static state of specimen deformation (i.e., either undeformed or completely flexed). Velocity profiles predicted by 2D CFD simulations of the paddlewheel mechanism compared well with PIV measurements, and were used to determine boundary conditions in localized 3D simulations.

For undeformed specimens, predicted inter-specimen variations in wall shear stress were on average +/-7%, with an average wall shear stress of 1.145 dyne/cm(2) predicted at a paddlewheel speed of 2000 rpm and standard culture conditions. In contrast, while the average wall shear stress predicted for specimens in the quasi-static flexed state was approximately 59% higher (1.821 dyne/cm(2)), flexed specimens exhibited a broad intra-specimen wall shear stress distribution between the convex and concave sides that correlated with specimen curvature, with peak wall shear stresses of approximately 10 dyne/cm(2). This result suggests that by utilizing simple flexed geometric configurations, the present system can also be used to study the effects of spatially varying shear stresses. We conclude that the present design provides a robust tool for the study of mechanical stimuli on in vitro engineered heart valve tissue formation.

Source:

Annals of Biomedical Engineering. 2008 May.  36(5):700-12.



Grant of the Month

PI

Alan Russell

Co-Investigators

Marina Kameneva, William Wagner, Jörg Gerlach, Mark Yazer

Title

Large Scale Human Placenta Progenitor Cell-Derived Erythrocyte Production – Continuous Red Blood Cell Production

Description

In order to provide a practical and ready supply of safe and effective red blood cells (RBC) for the treatment of battlefield trauma, or diseases, a number of fundamental challenges must be overcome.  These challenges are associated with current small-scale, variable efficiency in vitro cell expansion and erythrogenic differentiation of hematopoietic stem cells (HSC) and include:

  • Reducing the quantity of media required to expand and differentiate sufficient HSC in vitro.  Conventional culture systems operate at cell densities of 1x105-1x107 per ml and would require far in excess of the ~1300 liter volume maximally available in the 47cuft DARPA specification to generate 2x1012 RBCs associated with a unit of whole blood.
  • Reducing minimum ~21 day period currently required to generate ~ 2x1012 RBCs from conventional HSC numbers (~5x107) derived from umbilical cord blood (hUCB)
  • Safely reducing the senescence rate of self-renewing HSC which currently limits the rate and absolute level of HSC expansion.
  • Maintaining the pluripotency of the expanded CD34+ population thereby limiting the progressive decrease in pluripotentiality currently observed in expanded HSC populations.
  • Demonstrating significant proof of concept and reduction to practice in <36months while assuring that the product will be safe and effective.

 

To overcome these challenges, a consortium led by Celgene Cellular Therapeutics (CCT) and supported by the University of Pittsburgh/Institute for Transfusion Medicine, Fred Hutchinson Cancer Research Center, The Ohio State University, Loughborough University and The Automation Partnership has been assembled. This consortium will provide all of the necessary skills (cell biology, hematology, cellular therapeutic process development, bioreactor systems, cells separation technology and automation) to ensure effective and safe research, and RBC product development.  The multidisciplinary consortium will develop highly novel and / or unique solutions that include:

  • Initiating the process with a high number of cells available by combining HSC derived from umbilical cord blood with human placental perfusate (hPP) that contain highly erythrogenic progenitors and can be obtained in a ready supply post-partum from type O Rh-ve donors.
  • Using immobilized Notch ligands to prevent senescence and maintain erythrogenic differentiation potential during multi-log increase in the number of HSC.
  • Incorporating selected Celgene proprietary compounds (IMiDs) with the aim of enhancing the expansion of HSC, without a significant loss in multipotentiality, and to enhance erythropoiesis and modulate globin gene expression during differentiation.
  • Transient and safe genetic engineering of HSC, in order to modulate cell cycle phase transition times and enhance HSC expansion prior to enrichment of enucleated erythrocytes.
  • Development of a semi-fieldable centralized and fieldable automated cell culturing system, to ensure that the footprint of the fieldable unit is <47cubic feet and that battlefield use is fully automated and robust to use by minimally trained personnel. Semi-fieldable processing systems will incorporate large-scale batch methods in central or near-battlefield cell expansion centers. The fieldable bioreactor will be based on current prototype bioreactor that can accurately mimic the bone marrow microenvironment and can culture up to 1x1011 cells in one 800ml cell compartment system, requiring ~2liters of medium in the circuit.
  • Development of near-continuous non-invasive sorting systems to enrich progenitors committing to erythrogenic differentiation pathways and to ensure consistency, safety and efficacy of the final product.

Source

Defense Advanced Research Projects Agency

Term

09/01/08 – 05/31/09

Amount: $760,804

Newsletter Comments or Questions: McGowan@pitt.edu