1. NanoBioMechanics / Orthopedic Biomechanics 2. Decorin: A Central Regulator of Cartilage Extracell
Wednesday, January 13, 2021
4:00 PM-5:30 PM
BIOMED Dual Seminar
Title Seminar #1:
NanoBioMechanics / Orthopedic Biomechanics
Speaker:
Sriram Balasubramanian, PhD
Associate Professor
School of Biomedical Engineering, Science and Health Systems
Drexel University
Details:
This talk will provide a comprehensive overview of pediatric spine anatomy and growth, pediatric spine deformities, and surgical treatments. Additionally, the talk will also focus on innovative finite element modeling tools that have been developed in the Orthopedic Biomechanics Lab for surgical simulation and planning. Ongoing work in the areas of machine learning for automated spine segmentation, deformity prediction and surgical guidance will also be discussed.
Biosketch:
Sriram Balasubramanian, PhD, is an associate professor in the School of biomedical Engineering, Science and Health Systems and Director of the Orthopedic Biomechanics Laboratory at Drexel University. Dr. Sri’s primary training and expertise lie in biomechanical testing to investigate injury tolerance of orthopedic tissue. After joining Drexel in 2010, Dr. Sri established two additional and complementary areas of expertise: one focused on dynamic testing of pediatric human subjects and other focused on characterizing and modeling pediatric spine deformities. With strong collaborations with top pediatric hospitals and researchers, Dr. Sri’s research findings in these under-studied areas have made tremendous impact on the current practices in pediatric orthopedics and automotive child safety, and also provide the data and methods needed to guide future innovations. Dr. Sri also helped characterize the biomechanical response of neural tissue, with recent efforts focused on studying the effects of traumatic mechanical loading on neonatal brachial plexus and spinal cord. He has taken the approach to apply his expertise in experimental biomechanics to study injury mechanisms and provide translational data needed to develop computational tools that can be used for pediatric injury prevention.
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Title Seminar #2:
Decorin: A Central Regulator of Cartilage Extracellular Matrix Health and Disease
Speaker:
Lin Han, PhD
Associate Professor
School of Biomedical Engineering, Science and Health Systems
Drexel University
Details:
The extracellular matrix (ECM) of cartilage mainly consists of type II/IX/XI heterotypic collagen fibril network entrapping the large proteoglycan, aggrecan. Integrity of the ECM is essential for proper joint biomechanics and chondrocyte mechanoregulation. Currently, the limited understanding of cartilage ECM represents a major roadblock to the development of effective regeneration and disease intervention strategies. We discovered a critical role of decorin, a small leucine-rich proteoglycan (SLRP), in regulating cartilage ECM biomechanics and mechanobiology. In cartilage, decorin functions as a “physical linker” to increase the adhesion of aggrecan molecules, thereby strengthening the ECM integrity. With the loss of decorin, decorin-null murine cartilage develops a substantial reduction of aggrecan content, with mild changes in collagen nanostructure. These defects contribute to significantly impaired cartilage biomechanics, including reduced elastic modulus and elevated hydraulic permeability. Furthermore, this decorin loss-induced aggrecan reduction leads to impaired cartilage pericellular matrix at the microscale, resulting in demoted intracellular chondrocyte Ca2+ responses in situ. When subjected to the destabilization of the medial meniscus (DMM) surgery, decorin-null mice develop more severe osteoarthritis (OA) than the control, signified by the reduced modulus, accelerated aggrecan depletion and pronounced surface fibrillation. These results underscore the indispensable role of decorin in the overall structural integrity and mechanobiology of cartilage ECM in both healthy and OA tissues. Modulation of decorin activities could provide a novel path to improve the quality of engineered cartilage and attenuate the degeneration of cartilage in disease.
Biosketch:
Lin Han, PhD, is an associate professor in the School of Biomedical Engineering, Science and Health Systems at Drexel University. He obtained his PhD degree at MIT in 2007. His PhD thesis focused on the molecular, cellular and tissue nanomechanics of cartilage. He later worked as a post-doctoral associate at MIT, where he continued the exploration of nanostructure and nanomechanics of soft and hard biological tissues. Dr. Han's current research aims to tackle the interdisciplinary challenges in the development, regeneration and degeneration of biological tissue extracellular matrix (ECM) by integrating novel approaches in nanotechnology, biomaterials, biomechanics, matrix biology and gene therapy, with a focus in three ECM biomolecules, aggrecan, decorin and type V collagen.
Contact Information
Lisa Williams
ltw22@drexel.edu