Category Archives: Seminars

Biomedical Engineering Graduate Seminar: Stem Cell-based Musculoskeletal Tissue Regeneration

oct17Biomedical Engineering Graduate Seminar: Wan-Ju Li, Phd, Department of Biomedical Engineering, University of Wisconsin-Madison; Friday, October 17; 3:00 in U113 M&M;
Sponsored by: Department of Biomedical Engineering and the Biotechnology Research Center (BRC)

Title: Stem Cell-based Musculoskeletal Tissue Regeneration

Mesenchymal stem cells (MSCs) can be isolated from several adult tissues, such as bone marrow, fat, and blood, and cultured in vitro for extensive propagation. These cells are multi-potent, and with proper biochemical or physical cues, they can differentiate into various connective tissue linage cells, such as osteoblast, chondrocyte, adipocyte, and tenocyte. Notably, transplanted allogeneic MSCs can regulate the activity of recipient’s immune cells to reduce the immune response. These unique properties make MSCs an attractive cell source for cell therapy and re-generative medicine applications.
Using MSCs to regenerate cartilage for tissue repair is a promising treatment to osteoarthritis (OA) or other cartilage defects. However, one of the challenges using MSCs for regenerative medicine is that the cells isolated from adult tissues are often composed of heterogeneous cell popu-lations, and the heterogeneity increases the difficulty of using the cells for cartilage regeneration. Another challenge is that MSCs become aged and senescent after several cell passages in vitro culture, limiting the use for clinical applications. To overcome the challenges, we derive MSCs from human embryonic stem cells (hESCs) and study the potential of hESC-MSCs for cartilage regeneration. We compare the phenotype of hESC-MSCs with that of bone marrow-derived MSCs. Flow cytometry analysis shows that MSCs and hESC-MSCs express similar cell surface markers. In terms of the potential for chondrogenesis, the mRNA transcript levels of chondrocyte-related matrix proteins and transcription factors, such as collagens type II, IX, and X, aggrecan, and Sox9, are upregulated in MSCs compared to those in hESC-MSCs during chondrogenesis, suggesting that the current differentiation protocol more effectively induces MSCs into chondrocytes than hESC-MSCs, and an improved differen-tiation protocols should be developed to induce chondrogenesis of hESC-MSCs.
For tissue engineering applications, we demonstrate a unique approach using a biomimetic scaffold, intervertebral disc (IVD) and stem cell coculture, and mechanical stimulation to tissue-engineer a biological IVD substitute. The results show that our approach provides both favorable physical and chemical cues through cell-matrix and cell-cell interactions and mechanobiological induction to enhance IVD generation ex vivo. Taken together, we have shown the potential of using stem cell and nanofabrication technologies to regenerate functional tissue for orthopedic treatment.

Professor Wan-Ju Li is the Principal Investigator of the Musculoskeletal Biology and Regenerative Medicine Laboratory at the University of Wisconsin-Madison in the United States of America. He is also an affiliated faculty member in Cellular and Molecular Biology Program, and Stem Cell and Regenerative Medicine Center. His research interests include stem cell, tissue engineering, nanobiomaterial, and skeletal biology.

Seminar: Instrumenting the Human Body

sep22Seminar presentation jointly sponsored by Michigan Technological University’s College of Engineering and the Departments of Biomedical Engineering and Electrical and Computer Engineering
Date: Monday, September 22, 2014; Time: 4:00-5:00 p.m.; Location: M&M U115
Title: Instrumenting the Human Body
Richard B. Brown, Ph.D., Dean of Engineering, University of Utah, Salt Lake City

Abstract: Advances in semiconductor technology are enabling research into, and treatment of, many human diseases. Prof. Brown will present a highly‐integrated, low‐power, wireless, mixed-signal microprocessor that was designed for implantable biomedical applications, and braincomputer interfaces that enable researchers to monitor electrical firing of individual neurons, local field potentials, and chemical signaling in the brain.

Biography: Prof. Brown earned the degrees BS and MS in Electrical Engineering from Brigham Young University. After working in industry for six years, he returned to school at the University of Utah and received the degree PhD in EE in 1985, developing one of the first “smart sensors,” an array of liquid chemical sensors with integrated electronics. Upon graduation, he joined the faculty of the University of Michigan, where he developed their VLSI program and conducted research on circuits (high‐speed, low‐power, high‐temperature, and radiation hard), microprocessors (high‐performance, low‐power, and mixed‐signal), sensors (for ions, heavy metals, and neurotransmitters), and brain‐machine interfaces. At Michigan he held an Arthur F. Thurnau Endowed Professorship. In 2004, he was appointed Dean of the College of Engineering at the University of Utah, where he has continued to do research on circuits, mixed-signal microcontrollers and neural interfaces. Prof. Brown has been a founder with his students of Mobius Microsystems (all‐silicon clock generators), i‐SENS (glucose sensors), Sensicore (water chemistry sensors), and e‐SENS (chemical sensors). He holds 17 patents, has authored more than 225 peer‐reviewed publications, and graduated 30 PhD students.

Richard B. Brown, Ph.D., Dean of Engineering, University of Utah, Salt Lake City presented a seminar at Michigan  Title: Instrumenting the Human Body; Shown here 2nd from left with Michigan Tech faculty, Paul Bergstrom, ECE Chair Daniel Fuhrmann and Saeid Nooshabadi
Richard B. Brown, Ph.D., Dean of Engineering, University of Utah, Salt Lake City presented a seminar at Michigan Title: Instrumenting the Human Body; Shown here 2nd from left with Michigan Tech faculty, Paul Bergstrom, ECE Chair Daniel Fuhrmann and Saeid Nooshabadi

Seminar: Vascularized Bone Grafts for Craniofacial Regeneration

sep5Biomedical Engineering Graduate Seminar: Warren Grayson, Ph.D. Assistant Professor, Biomedical Engineering, Johns Hopkins University; Friday, September 5 – 138 Fisher at 10:00 a.m.

Title: Vascularized Bone Grafts for Craniofacial Regeneration

The treatment of large bone loss due to congenital defects, trauma or cancer resection remains a huge clini-cal challenge. There are approximately one million fractures requiring bone transplantation annually in the US and it is predicted that within the next 10 years this number will significantly increase, particularly in per-sons over 50 years of age. Tissue engineering provides a viable means of obtaining ‘autologous’ bone grafts for the treatment of large bone defects. Successful application of tissue-engineered grafts however requires that we can couple the formation of de novo vasculature in tandem with new bone growth. Our lab has investigated methods for cultivating anatomically-shaped bone grafts in bioreactors and pre-vascularizing these grafts via co-culture techniques. More recent studies have examined the use of adipose-derived stem cells (ASCs) to engineer vascularized bone grafts that can be used to repair craniofacial de-fects. We have found that heterotypic interaction among endothelial and non-endothelial sub-populations mediate by growth factor effects can choreograph the formation of complex tissue grafts. These findings suggest the tremendous potential for using ASCs in concert with engineering techniques to provide clinically relevant vascularized bone grafts for the repair and regeneration of craniofacial bone loss.

This seminar is partially funded by the Visiting Women & Minority Lecturer/Scholar Series which is funded by the President’s Office and a grant to the Office of Institutional equity from the State of Michigan’s King-Chavez-Parks Initiative

Biomedical Engineering Graduate Seminar

Biomedical Engineering Graduate Seminar: Dr. Monica Hinds, Associate Professor, Department of Biomedical Engineering, Oregon Health & Science University; Friday, 4/18 at 3:00 in U113 M&M

Title: Endothelialization of Vascular Biomaterials

In developing blood-contacting vascular biomaterials, a confluent endothelial cell (EC) monolayer may be required to avoid adverse blood reactions. In vitro, the hemostatic properties (“thrombogenicity”) of ECs have typically been char-acterized using anticoagulated blood, static or non-physiologic flow conditions, and short blood exposure times. Con-sequently, the relevance of these findings for in vivo applications remains uncertain. Moreover, there have been few studies of the reactivity of EC constructs in vivo, and no studies have been reported that systematically relate the in vitro properties of endothelialized surfaces with their responses in vivo. Accordingly, it is now recognized within the tissue engineering community that a key impediment to further progress towards applications in man is the lack of predictive animal models that will enable the rational design of cellular constructs. We are characterizing the in vitro and ex vivo pro-hemostatic and anti-hemostatic properties of ECs (that can affect platelets and coagulation), and im-portant in vivo responses of thrombosis and vascular healing in a physically relevant primate model. Endothelial out-growth cells (EOCs), isolated from the circulating endothelial progenitor cells of baboons, have been seeded on pro-tein-coated ePTFE vascular grafts. We have studied the role of extracellular matrix coatings and hemodynamic pre-conditioning on the EOC phenotype, particularly related to coagulation and inflammation. Subsequently, in an ex vivo baboon shunt model, platelet and fibrin accumulation were measured under conditions of controlled, native blood flow. Finally, the endothelialized vascular grafts were implanted as aorto-iliac interposition grafts for 28 days. After a thorough evaluation of potential correlations, a linear regression model using in vitro data was established to predict platelet accumulation. This regression correlated significantly and strongly to both ex vivo platelet and in vivo intimal hyperplasia data. This is the first work of this type—attempting to determine predictors for vascular graft performance from in vitro endothelial markers, and while future work should examine the scope of the model by applying it to other endothelialized grafts, we are encouraged by these results, which may aid in improving translation of small diameter vascular grafts into clinical improvements.

This seminar is partially funded by the Visiting Women & Minority Lecturer/Scholar Series which is funded by the President’s Office and a grant to the Office of Institutional equity from the State of Michigan’s King-Chavez-Parks Initiative

Biomedical Engineering Graduate Seminar: Magnesium-Neodymium Alloys for Biomedical Applications

Biomedical Engineering Graduate Seminar:
Dr. Jan-Marten Seitz, Institut für Werkstoffkunde, Leibniz Universität Hannover, Garbsen, Germany
Friday, April 4 at 3:00 in U113 M&M

Title: “Development and Characterization of Magnesium-Neodymium Alloys for Biomedical Applications”
The aim of the presented study is to investigate and demonstrate the potential of neodymium additions as a substitute for rare earth (RE) misch-metal in magnesium alloys for biomedical applications. Here, the alloys LAE442, LANd442, ZEK100, ZNdK100, and Nd2 were manufactured and processed to evaluate their material characteristics in different states and to investigate the effects of Nd additions. To determine the mechanical characteristics of these alloys, tensile tests were initially carried out in the hot extruded state. Subsequent T5- and T6-heat treatments were con-ducted to reveal their effect on the alloys’ strength and elongation values. The general degradation behavior of the alloys in a 0.9% NaCl solution was investigated by means of polarization curves and hydrogen evolution. In addition, by using various in-vivo-parameters, a corrosion environ-ment was established to determine the alloys’ degradation in vitro. Comparing LAE442 and LANd442, a lack of corrosive stability could be ob-served while the mechanical strength remained constant in the latter alloy’s Nd substitution for the RE mischmetal. A contrary effect was deter-mined for the alloy ZEK100 compared with ZNdK100. In both substitutional approaches, heat treatment procedures could not align the substi-tutes’ material properties with the educts’ material properties. However, in the case of Nd2, which was initially chosen as relevant alloy to deter-mine the effects of Nd on Mg in a simple binary composition, excellent ductility and corrosion properties could be observed. This makes the alloy a promising candidate for use as resorbable implant material, especially in the field of stenting applications. Here, the enormous increase of duc-tility, promoted by an advantageous microstructural behavior under loadings, could be attributed to additions of Nd.

Biography: Within the past 5 years, Dr. Seitz has worked as a PhD Student and Scientist at Leibniz Universität in Hannover, Germany, with a focus on lightweight materials research and biomedical engineering applications. He developed process chains for resorbable Mg-implant applications such as stents, intramedullary nails, and sutures. This work included basic processes such as casting, hot-extrusion, heat treatment, drawing and coating procedures, as well as many analytical processes. The impact of different alloying elements on the mechanical and corrosive behavior of Mg in different conditions was one of the biggest challenges in this context. Besides the development of promising biodegradable Mg alloys, he also worked on the manufacture of thin wires from magnesium by means of extrusion and drawing processes. During an overseas stay at The University of Auckland, he developed polymer and ceramic based coatings for medical applications with magnesium and analyzed their structural behavior in a corrosive environment.

Biomedical Engineering Graduate Seminar

Megan Yi-Ping Ho, assistant professor in the Interdisciplinary Nanoscience Center at Aarhus University in Denmark will present a graduate seminar, “Towards Single Cell Diagnostics, Combining DNA Nanosensors and Microfluidics for Disease Diagnosis,” Friday, Aug. 30, at 3p.m., in Fisher 327B.