Illustration of processes of atherogenesis ranging from prelesional endothelial dysfunction (a) through monocyte recruitment to the development of advanced plaque complicated by thrombosis (b). The mechanisms are grossly simplified but focus on components (for example, cell adhesion molecules, macrophages, connective tissue elements, lipid core, and fibrin) and processes (for example, apoptosis, proteolysis, angiogenesis, and thrombosis) in plaques that have been imaged or that present useful potential imaging targets. ICAM, intercellular cell adhesion molecule; LDL, low‐density lipoprotein; MMP, matrix metalloproteinase; NO, nitric oxide; VCAM, vascular cell adhesion molecule. (Reprinted with permission. Copyright 2004 Macmillan Publishers Ltd.).
In vivo MRI of VCAM‐1 expression. (a) magnetic resonance imaging (MRI) before injection of VINP‐28. Dotted line depicts location of short‐axis view (insets, lower panel with color coded signal intensity). (b) Same mouse 48 h after injection of VINP‐28. A marked signal drop in the aortic root wall was noted(insets). The contrast‐to‐noise ratio (CNR) of the aortic wall was increased significantly after injection of the probe. (Reprinted with permission. Copyright 2006 Lippincott Williams and Wilkins).
Protection of nanofibrous grafts from thrombus by MSCs in vivo. Mesenchymal Stem Cell (MSC)‐seeded grafts show greatly reduced platelet aggregation to the luminal graft surface (b) and thrombus formation (d) after 2 h compared to acellular grafts (a,c). After 60 days, a cellular grafts display intimal thickening (e, arrow), while MSC‐treated grafts do not (f). (Modified with permission. Copyright 2007 National Academy of Sciences, U.S.A).
Injection of nanofibers (NF) with platelet‐derived growth factor (P‐BB) decreases cardiomyocyte death after myocardial infarction (MI). Immunofluorescence staining of cleaved caspase‐3, a marker of apoptotic cell death was shown in sections from 1 day after injection of NFs with or without P100. Blue, DAPI (4′, 6‐diamidino‐2‐phenylindole, nuclear marker); red, α‐sarcomeric actinin; green, cleaved caspase‐3. Colocalization of caspase‐3 with cardiomyocytes is shown in yellow. Journal of Clinical Investigation. Online by Richard Lee. Copyright 2006 by American Society for Clinical Investigation. (Reprinted with permission 2006 American Society for Clinical Investigation).
works at the interface of biotechnology and materials science. His lab is researching many topics, such as investigating the mechanism of release from polymeric delivery systems with concomitant microstructural analysis and mathematical modeling; studying applications of these systems including the development of effective long-term delivery systems for insulin, anti-cancer drugs, growth factors, gene therapy agents and vaccines; developing controlled release systems that can be magnetically, ultrasonically, or enzymatically triggered to increase release rates; synthesizing new biodegradable polymeric delivery systems which will ultimately be absorbed by the body; creating new approaches for delivering drugs such as proteins and genes across complex barriers such as the blood-brain barrier, the intestine, the lung and the skin; stem cell research including controlling growth and differentiation; and creating new biomaterials with shape memory or surface switching properties.