North Carolina A&T State University
NSF Engineering Research Center + Bioengineering Joint Seminar Series
11 AM – 11:50 AM – Friday, February 28, 2014
McNair Hall Auditorium – College of Engineering
NIH-SPIRE Postdoctoral Fellows
UNC/NCSU Joint Department of Biomedical Engineering
Chapel Hill, NC
1. Directed Energy Approaches for Cancer Treatment & Detection
Dr. Christopher Arena
Irreversible electroporation (IRE) is a non-thermal, focal ablation technique that has shown tremendous promise for the treatment of cancer. The procedure involves applying a series of electric pulses through electrodes inserted into the target tumor. The pulses produce irreversible structural changes in the cell membranes, generating a predictable range of cell death with sub-millimeter resolution. Because the mechanism of cell death is linked to altered membrane permeability and not thermal processes, IRE spares important extracellular matrix components, such as major blood vessel and nerve architecture. This enables the treatment of tumors that are normally considered surgically inoperable. Currently, over 1000 patients with kidney, liver, lung, prostate, and pancreatic cancer have been treated with IRE throughout the world.
Due to the fact that IRE is a focal ablation modality, successful outcomes go hand-in-hand with the early detection of pre-metastatic, localized, tumors. Molecular imaging aids in this process by using cancer biomarkers to detect the onset of disease. In one variety, ultrasound is combined with microbubble contrast agents that are targeted towards specific integrins expressed on new blood vessels that initiate tumor growth. Due to their size, microbubbles are restricted to the vascular network. To overcome this limitation, microbubbles can be condensed into nanodroplets prior to administration. Once the nanodroplets reach their extravascular targets, energy can be applied to vaporize them back into microbubbles so that they are once again visible on ultrasound. The use of nanodroplets has the potential to expand the number of cancer biomarkers that are suitable for ultrasound molecular imaging.
About the Speaker:
Dr. Christopher Arena received his B.S. degree in biomedical engineering from the University of Virginia and his Ph.D. degree from the Virginia Tech – Wake Forest University School of Biomedical Engineering and Sciences. He is currently a SPIRE postdoctoral fellow in the UNC/NC State Joint Department of Biomedical Engineering. As a graduate student, Chris led the development of a new platform for performing therapeutic irreversible electroporation. The system utilizes bursts of nanosecond pulses to induce non-thermal ablation with improved levels of patient comfort and outcome predictability. While at Virginia Tech, Chris co-founded the company VoltMed, Inc. based on this technology. As a postdoc, Chris, is working on using a new ultrasound technique called acoustic angiography to better characterize lesions caused by irreversible electroporation. Additionally, he is helping create ultrasound contrast agent detection schemes that take advantage of the unique acoustic signature emitted from vaporized nanodroplets. Chris is looking forward to drawing on these experiences while building a course and teaching at a SPIRE partner institution.
2. Building on Nature's Platform:
Hybrid Extracellular Matrix Scaffolds for Tissue Engineering Applications
Dr. Sonya Sonnenberg
Tissue engineering relies on combinations of cells, biomaterials, and external regulators such as growth factors or mechanical stimuli. As our understanding of the interaction between the host environment and the biomaterial of choice improves, we are able to design better scaffolds for specific applications. Recently, decellularized extracellular matrix scaffolds have been investigated for a variety of applications, both as intact 3D scaffolds, injectable hydrogels, and cell culture coatings. These materials have shown great promise as bioinstructive scaffolds, promoting constructive remodeling after injury. However, their poor mechanical properties prevent them from being useful in orthopedic applications. Moving toward hybrid scaffolds that combine nanofibrous electrospun synthetic polymers with a tissue-specific ECM hydrogel may improve the versatility of these promising materials.
About the Speaker:
Sonya Sonnenberg earned her BS at Arizona State University in 2008 and her PhD at the University of California, San Diego in 2012, both in Biomedical Engineering. Her research as a doctoral candidate focused on the development, characterization, and testing of injectable biomaterial scaffolds for the treatment of acute myocardial infarction, or heart attacks. Her work with naturally-derived extracellular matrix hydrogels lead to the first demonstration of their ability to sequester and deliver growth factors via resident sulfated sugars present in the hydrogels. Sonya is currently a SPIRE postdoctoral scholar in the Cell Mechanics Laboratory at the University of North Carolina, Chapel Hill. Her current research involves synthetic fiber reinforcement of extracellular matrix hydrogels for orthopedic applications, such as meniscus reconstruction. Sonya values clinical collaborations and has always focused on highly translational research, with the goal of developing therapies for patients.