Hak-Joon Sung, Ph.D.

Research Summary

My major research area is synthetic polymer-based chemical matrix biology, which involves a multifaceted approach that combines state of the art polymeric biomaterial systems, chemical/biochemical methodologies, and engineering tools. In recent years, the design concepts for polymeric biomaterials have developed to be fully integrated with principles from biochemistry and cell/molecular biology. Although considerable progress has been made, ongoing challenges remain in controlling dynamic biological signals through modification of polymer properties. To meet these challenges, I have utilized advanced biomaterials systems that apply combinatorial formats of polymer test platform and synthesis to generate thousands of distinguishable microenvironments for cells brought in contact with synthetic matrixes. The combinatorial methods that I have used are of two types: First, polymers are blended. Then composition spread and temperature gradient techniques are applied to generate surface libraries with controlled variations in chemical, physical, and morphological properties. This method offers the ability to efficiently measure relevant polymer surface properties and to study cellular responses over large regimes of variable space simultaneously. Second, combinatorial synthesis is applied to prepare a library of polymers that offers the potential to prepare every combination of substrates, type A1–x and type B1–y, providing a set of compounds, A(1–x)B(1–y). These combinatorial methodologies provide high-throughput formats to study structure–function relationships of synthetic materials in terms of their ability to produce molecular, cellular, and tissue level biological outcomes. The goal of my research is to identify the underlying mechanisms by which cells and tissues interact with polymeric matrixes and coordinate dynamic biochemical signals to change their microenvironments, and to apply this knowledge to develop the next generation of polymeric biomaterials for regenerative medicine and medical device technologies. In particular, my group is developing bioactive polymeric scaffolds controlling angiogenesis and inflammation for regeneration of various tissues. Through this project, my group seeks to understand cross functional relationships between inflammation and angiogenesis in the context of biomaterial implants. My group is also investigating oxidative stress-sensitive properties and phase separation-mediated smart functionalities of biomaterial systems. These efforts aim at developing the next generation of biomaterials controlling vascular homeostasis and regeneration (i.e., stent and patch) and stem cell transformation and differentiation (i.e., multifunctional scaffolds).

Research Keywords

Biomaterials and Biointerface for Vascular and Stem Cell Engineering

» Johnson PA, Luk A, Demtchouk A, Patel H, Treiser MD, Gordonov S, Sheihet L, Bolikal D, Kohn J, Sung HJ, and Moghe PV. “Interplay of Anionic Charge, Poly(ethylene glycol), and Iodinated Tyrosine Incorporation within Tyrosine-derived Polycarbonates: Effects on Vascular Smooth Muscle Cell Adhesion, Proliferation and Motility.” J. Biomedical Mater. Res. A. 2009 Jul 7. [Epub ahead of print].

» Liu E, Treiser MD, Patel H, Sung HJ, Kohn J, Becker ML, and Moghe PV. “High Content Profiling of Cell Responsiveness to Graded Substrates Based on Combinatorially Variant Polymers.” Combinatorial Chemistry & High Throughput Screening. 2009 Aug 1. [Epub ahead of print]

» Sung HJ, Chandra P, Treiser MD, Liu E, Iovine CP, Moghe PV, and Kohn J. “Synthetic Polymeric Substrates as Potent Pro-Oxidant Versus Anti-Oxidant Regulators of Cytoskeletal Remodeling and Cell Apoptosis.” Journal of Cellular Physiology. 2009;218(3):549-57.

» Sung HJ, Sakala Labazzo KM, Bolikal D, Weiner MJ, and Kohn J. “Angiogenic Competency of Biodegradable Hydrogels Fabricated from PEG-Crosslinked Tyrosine-Derived Polycarbonates.” European Cells and Materials. 2008; 15:77-87.

» Treiser MD, Liu E, Dubin RA, Sung HJ, Kohn J, and Moghe PV. “Profiling Cell-Biomaterial Interactions Via Cell-Based Fluororeporter Imaging.” Biotechniques. 2007; 43:361-8.

» Sung HJ, Yee A, Eskin SG, and Mcintire LV. “Cyclic strain and motion control produce opposite oxidative responses in two human endothelial cell types.” American Journal of Physiology-Cell Physiology. 2007; 293:87-94.

» Sung HJ, Eskin SE, Sakurai Y, Yee A, Kataoka N, and McIntire LV. “Oxidative Stress Produced with Cell Migration Increases Synthetic Phenotype Properties of Vascular Smooth Muscle Cells.” Annals of Biomedical Engineering. 2005; 33(11): 1546-54.

» Sung HJ*, Jing S, Berglund JD, Meredith C, and Galis ZS. “The Use of Temperature-Composition Combinatorial Libraries to Study the Effects of Biodegradable Polymer Blend Surfaces on Vascular Cells.” Biomaterials. 2005; 26(22):4557-67.

» Sung HJ*, Johnson C, Lessner SM, Magid R, Drury DN, and Galis ZS. “Matrix Metalloproteinase (MMP)-9 Facilitates Collagen Remodeling and Angiogenesis for Vascular Constructs.” Tissue Engineering. 2005; 1(1-2):267-76.

» Lee DH, Sung HJ, Han DW, Lee MS, Ryu GH, Aihara M, Takatori K, and Park JC. “In Vitro Bioassay of Endotoxin Using Fluorescein as a pH Indicator in a Macrophage Cell Culture System.” Yonsei Medical Journal. 2005; 46(2):268-74.

» Johnson C, Sung HJ, Lessner SM, Fini ME, and Galis ZS. “Matrix Metalloproteinase-9 is Required for Adequate Angiogenic Revascularization of Ischemic Tissues: Potential Role in Capillary Branching.” Circulation Research. 2004; 94(2):262-8.

» Sung HJ, Meredith JC, Johnson C and Galis ZS. “The Effect of Scaffold Degradation Rate on the Three-Dimensional Cell Growth and Angiogenesis.” Biomaterials. 2004; 25(26):5735-42.

» Khatri JJ, Johnson C, Magid R, Lessner SM, Laude KM, Dikalov SI, Harrison DG, Sung HJ, Rong Y, and Galis ZS. “Vascular Oxidant Stress Enhances Progression and Angiogenesis of Experimental Atheroma.” Circulation. 2004; 109(4):520-5.

» Park JC, Suh H, Sung HJ, Han DW, Lee DH, Park BJ, Park YH, and Cho BK. “Liposomal Entrapment of Cefoxitin to Improve Cellular Viability and Function in Human Saphenous Veins.” Artificial Organs. 2003; 27(7):623-30.

» Park JC, Sung HJ, Lee DH, Park YH, Cho BK, and Suh H. “Antibacterial Effect of Antibiotic Solution on Cellular Viability in Canine Veins.” Artificial Organs. 2000; 25(6):490-4.

» Park JC, Sung HJ, Lee DH, Park YH, Cho BK, and Suh H. “Specific Determination of Endothelial Cell Viability in the Whole Cell Fraction from Cryopreserved Canine Femoral Veins Using Flow Cytometry.” Artificial Organs. 2000; 24(10):829-33.

» Park JC, Sung HJ, Lee DH, Park YH, Cho BK, and Suh H. “Viability of Cells in Cryopreserved Canine Cardiovascular Organs for Transplantation.” Yonsei Medical Journal. 2000; 41(5):556-62.