Biography: Dr. Xiangdong Bi received a Ph.D. in chemistry from University of Missouri-Kansas City in 2001. After graduation, he worked as a postdoctoral fellow at Wayne State University in medicinal chemistry for 3 years. In 2004, he pursued further research at the medical school of University of Michigan in the field of nanotechnology for cancer targeting and treatment. Dr. Xiangdong Bi started his teaching career at Charleston Southern University (CSU) in 2007. He is currently a tenured full professor in chemistry at CSU. His research interest includes organic synthesis and bioconjugation of macromolecules for biomedical applications, particularly PAMAM dendrimer mediated hydrogels for tissue engineering and drug delivery. From 2009, he has received multiple grants from Department of Defense (DoD) and South Carolina EPSCoR to support his undergraduate research programs.
Topic: PAMAM Dendrimer-Mediated Functionalized in Situ-Forming Hydrogel Systems for Biofabrication
Abstract: Hydrogels possess great potential in biofabrication because they allow for cell encapsulation and proliferation in a highly hydrated three-dimensional environment, and they provide biologically relevant chemical and physical signals. However, development of hydrogel systems that mimic the complexity of natural extracellular matrix (ECM) remains a challenge. In this research, we report the development of binary hydrogel systems containing a PAMAM dendrimer and a natural or synthetic polymer, i.e. hyaluronic acid (HA) or polyethyleneglycol (PEG), to form in situ crosslinking hydrogels through thiol-ene Michael addition. Hydrogels with varied gelling speeds and mechanical properties can be achieved by the type of crosslinkers conjugated on dendrimer as well as by the concentrations of dendrimer and polymer ingredients. The biocompatibility of the hydrogels is demonstrated by viability assays of a number of cell lines including rat mesenchymal stem cells (MSC) and human umbilical vein endothelial cells (HUVEC) after 48 hours of three-dimensional cell culture in hydrogels. Introduction of a RGD peptide into the hydrogel system significantly improved the cell viability, proliferation, and attachment. These PAMAM dendrimer medicated functionalized hydrogel systems with well-defined structures and tunable mechanical properties may serve as suitable scaffolds for tissue engineering and repairs of soft and hard tissue defects. In addition to the results from our research, some new developments and applications of hydrogels in biomedical fields will also be reviewed.
Biography: Dr. Meng-Hsuan Chung is a Professor of the Department of Naval Architecture and Ocean Engineering at National Kaohsiung University of Science and Technology, where he has been since 2006. He received a B.S. and M.S. from National Taiwan University in 1987 and 1989 respectively. He received his Ph.D. in Applied Mechanics from the same university in 1995. From 1995 to 2006 he worked at National Center for High-performance Computing as an Associate Research Scientist (1995-2000), First International Computer Inc. as a Senior Engineer (2000), National Space Program Office as an Associate Researcher (2000-2001), and Sinotech Engineering Consultants, Inc. eventually as a Senior Research Scientist (2001-2006).
His research interests span various aspects of computational fluid dynamics, including development and application of numerical method. Much of his work has been on developing a robust and efficient cut-cell Cartesian grid method to handle problems with moving bodies and/or fluid-fluid interfaces. The method features the adaptive mesh refinement and high-resolution reconstruction of solid boundaries. The numerical method has been employed to study the underwater biomimetic (rowing, undulating, and flapping) propulsion, and the vortex induced vibration of a circular cylinder near a rigid wall, free surface, or another cylinder. As of 2017, he is the author of 14 journal papers, including 12 single-authored ones. His biography was selected into Marquis Who’s Who in the World each year during 2010-2018.
Topic: Adaptive Cartesian Cut-cell Simulation of Conjugate Heat Transfer on Arbitrarily Moving Solid Boundaries
Abstract: This study developed and validated a numerical method to handle two-dimensional mixed-convection conjugate heat transfer (CHT) over arbitrarily moving/deforming fluid-solid interfaces. We will base the development on the finite-volume adaptive Cartesian grid method with the cut cell approach developed and matured previously. Few studies in literature tackled the issue of CHT across moving/deforming interfaces, especially in the community of Cartesian grid methods. The present work benefited from the merit of the cut cell approach, adapting to various types of boundary condition in a unified manner, to implement the boundary conditions required of the CHT. The proposed numerical method has nominally second-order accuracy in both space and time, although the temporal accuracy could be locally reduced to first order for solution cells adjacent to moving fluid-solid interfaces. Some cases were simulated to demonstrate the validity and spatial order of accuracy of the numerical method.