Fall 2004–Spring 2005 BME Seminars

September 16 
Omar Ghattas, PhD
Director, Ultrascale Simulation Lab
Professor, Department of Biomedical Engineering 
Professor, Department of Civil & Environmental Engineering
Carnegie Mellon University
Image-based Deformable Registration for Patient-Specific Surgical SimulationDirect generation of high-quality patient-specific physical models for surgical simulation requires image segmentation, surface reconstruction, mesh generation, and model construction, and is difficult to automate fully for complex anatomic geometries. We consider simulation of orthopedic surgical procedures based on CT images. We overcome the problem of generating patient-specific models by generating several high-quality template meshes offline. Then, for a given patient's CT image, we employ image-based registration techniques to elastically deform the template mesh so that it conforms to the patient's geometry. Examples demonstrate that direct-from-CT finite element models can be generated rapidly and robustly.

September 23
Bernhard Palsson, PhD
Professor, Department of Bioengineering
University of California at San Diego
Bringing Genomes To Life: The Role of Genome-Scale In Silico Models

October 7
Charles Friedman, PhD
Professor of Medicine, Director of the Center for Biomedical Informatics, 
and Director of the Medical Informatics Training Program
University of Pittsburgh
A Fundamental Theorem of Biomedical Informatics OR What Is Informatics Anyway?

October 21
Robert Murphy, PhD
Professor of Biological Sciences and Biomedical Engineering
Carnegie Mellon University
Location Proteomics: Protein Tagging, High-Throughput Fluorescence Microscopy and Machine Learning

October 28
Matthew O'Donnell, PhD
Professor and Chair, Biomedical Engineering 
Professor, Electrical Engineering & Computer Science 
Jerry W. and Carol L. Levin Professor of Engineering
University of Michigan
Can Vulnerable Plaques Really Be Detected?

November 18
Kevin Healy, PhD
Associate Professor, Departments of Bioengineering and Materials Science & Engineering
University of California at Berkeley
Challenges in Designing Materials that Dictate Tissue Regeneration
A central limitation in the performance of materials used in the medical device industry is that they lack the ability to integrate with biological systems through either a molecular or cellular pathway. This inability to interact with biological systems has relegated biomaterials to a passive role dictated by the constituents of a particular environment, leading to unfavorable outcomes and device failure in some cases. New classes of materials are being designed to overcome this limitation by actively directing the formation of organ specific tissue in contact with the material. Toward this goal, we have designed and synthesized model biomimetic materials that can be used to test hypotheses regarding cell-materials interactions. This lecture will first emphasize surface engineering strategies for modification of medical devices and subsequently will address design rules to guide the synthesis and fabrication of artificial extracellular matrices for in situ tissue regeneration. The universal nature of biomimetic modification strategies and characterization modalities will be addressed in the context of these examples.

February 3
Mark Saltzman, PhD
Goizueta Foundation Professor of Chemical and Biomedical Engineering
Chair, Department of Biomedical Engineering
Yale University
"Controlled Drug Delivery Systems for Cancer Therapy"

February 17
Professor Dame Julia M. Polak 
Imperial College Tissue Engineering & Regenerative Medicine Centre
Chelsea & Westminster Campus
London, England
"Stem Cells & Regenerative Medicine"

Regenerative medicine is an emerging field that approaches the repair or replacement of tissues and organs by incorporating the use of cells, genes or other biological building blocks along with bioengineered materials and technologies. Advances in stem cell biology, including the isolation and characterization of embryonic and post-natal somatic stem cells, have made the prospect of tissue regeneration a potential clinical reality. The Imperial College Tissue Engineering & Regenerative Medicine Centre is a base of operations for the college's leading scientists and clinicians to pool their expertise to develop tissue engineering, cellular therapies, biosurgery and artificial and biohybrid organ devices. Currently, the Centre is focusing on the repair of the musculo-skeletal and cardio-pulmonary systems testing a variety of approaches to control the differentiation of stem cells to the required cell phenotypes. Thus, continuously renewable pools of cells for repair are being established by deriving mature phenotypes, specifically osteoblasts, chondrocytes and pneumocytes, from stem cells and these are being grown with the aim of constructing tissues for implantation. In parallel, the mechanisms controlling naturally occurring repair systems are being investigated in order to identify potential means for upregulation.

March 24
Lori Setton, PhD
Mary Milus Yoh and Harold L Yoh, Jr. Bass 
Associate Professor of Biomedical Engineering
Assistant Research Professor of Orthopaedic Surgery
Duke University"A Rational Approach to the Design of Hydrogels for Cartilage Repair" 
An important goal of successful cartilage repair is early restoration of the native mechanical, physicochemical, and biochemical environments. Challenges exist, however, in simultaneously achieving these goals with any one strategy. Our laboratory has interests in determining optimal solutions for cartilage repair based on clusters of mechanical, physicochemical and biochemical parameters that are identified numerically or statistically. Using sets of injectable, in situ crosslinking scaffolds, we illustrate a rational approach to biomaterial design that is appropriate for achieving a targeted set of outcomes for cartilage repair.

April 7
Yoram Rudy, PhD
The Fred Saigh Distinguished Professor of Biomedical Engineering
Washington University at St. Louis
"From Genetics to Cellular Function Using Computational Biology" 
Most experimental data on the kinetic properties of cardiac ion channels and their modification by genetic defects have been obtained in expression systems (e.g., Xenopus oocyte), away from the cellular environment where these channels function to generate the cardiac action potential. In my presentation, I will describe the use of computational biology (computer simulations) in integrating such information on single ion channels into models of the functioning cardiac cell. We use this approach to mechanistically relate molecular processes to whole-cell electrophysiological function and its manifestation in electrocardiographic waveforms. Examples will be provided from the congenital Long QT Syndrome and the Brugada Syndrome.

May 5

Julia Babensee, PhD

Department of Biomedical Engineering

Georgia Institute of Technology and Emory University"Biomaterials as Adjuvants" 

The advent of innovative combination products has raised new regulatory concerns previously not considered. Some such combination products combine biomaterials with cells, DNA, or proteins, and include tissue engineered constructs in which cells are delivered with a polymer component and protein or DNA vaccine systems with non-viral polymeric carriers. Since biomaterials are used as vehicles in such combination products, it is important to clarify the role of the biomaterial component in potentiating the immune responses towards the biological component due to the adjuvant effect of the biomaterial. In tissue engineering applications, immune responses are to be minimized while vaccine strategies seek to enhance the protective immune response. We have shown that poly(lactic-co-glycolic acid) (PLGA), a polymer commonly used in combination products, acts as an adjuvant in the immune response against co-delivered antigen. Furthermore, we have demonstrated that PLGA is a maturation stimulus for dendritic cells (DCs), the key antigen presenting cells, which when mature stimulate effective immune responses. A differential adjuvant effect has been demonstrated depending on the biomaterial used to treat DCs. The host response towards combination products is a fundamental limitation to translating what has been successful in vitro to successin vivo. There are a number of devices in the pipeline where there is the potential for immunological responses which can compromise device effectiveness. This research begins to put together the kinds of tools which will be needed to clarify the immunological situation with these devices and develop strategies to control immune responses so that the devices function as intended. In this way, use of these novel medical devices will be successfully translated from the lab bench to the living being.