Biomaterials / Biomechanics Research Overview
Biomaterial combines both material sciences and biomedical aspects. A biomaterial replaces a part or a function of the body in a safe, reliable, economic and physiologically acceptable manner. A variety of devices and materials are used in the treatment of disease or injury. Common examples include sutures, needles, catheters, plates, implants, artificial skin, implantable devices and tooth fillings. A biomaterial is a synthetic material used to replace part of a living system or to function in intimate contact with living tissue. A biomaterial deals with the design, synthesis and applications of both living and non-living materials for temporary and permanent replacement of human tissues.
Biomechanics implements broad knowledge of mechanical and civil engineering in solving biomedical problems. Biomechanics has a long history and has built a foundation for modern biomedical engineering. Mechanics is the engineering science that deals with studying, defining, and mathematically quantifying "interactions" that take place among "things" in our universe. Our ability to perceive the physical manifestation of such interactions is embedded in the concept of a force and the "things" that transmit forces among themselves are classified for purposed or analysis as being solid, fluid or some combination of the two. What alters mechanics into the field of biomechanics is the fact that biomechanics is the science that deals with the time and space response characteristics of biologic solids, fluids and viscoelastic materials to imposed systems of internal and external forces. The principles of biomechanics have been applied and used for monitoring physiologic function, processing the data thus accumulated, theories to explain the data, diagnosing why the human "engine" malfunctions as a result of disease, aging and ordinary wear, repairing and rehabilitating body parts and supporting ailing physiologic organs.
Faculty Research Interests
Health Sciences Tower 15-090
Summary : Despite major progress, cardiovascular diseases remain the leading cause of death in the western world. One of the major culprits in cardiovascular disease and in devices designed to treat or restore impaired cardiovascular function is the non-physiological flow pattern that enhances the hemostatic response mainly through platelet activation. Platelets have long been regarded as the preeminent cell involved in physiologic hemostasis and pathologic thrombosis. An innovative technique for measuring flow induced platelet activation has been developed, and its utility demonstrated in experiments conducted in recirculation devices (models of arterial stenosis, Left Ventricular Assist Device (LVAD), and mechanical heart valves). The mechanisms by which the non-physiologic flow patterns induce platelet activation and generate free emboli, that enhance the risk of cardioembolic stroke, was demonstrated in vivo with mechanical heart valves implanted in a sheep model. The results of this research will aid in elucidating physical forces that regulate cellular function in flowing blood, and may be applied to improve the design of blood recirculating devices and to develop more potent drugs for treating cardiovascular diseases.
Bioengineering Building - Room G05
Summary : Our goal is to better describe and understand the role of tissue heterogeneity in normal tissues and in the onset and development of diseases like cancer. Most tissues are comprised of a complex mixture of different cell types, and even cells within a clonal population exhibit a high degree of heterogeneity. However, the detailed behavior of individual cells is obscured in typical measurements which are averaged over cell populations. As a result, it has been difficult to comprehend the functional relevance of this heterogeneity due to the lack of adequate techniques. In order to enable the analysis of tissue heterogeneity we are developing an experimental approach based on droplet microfluidics that allows the manipulation of single cells by suspending them in drops carried in an inert fluid. These drops can then be automatically combined with reaction solutions, interrogated with fluorescent dyes or sorted to carry out sample preparation and analysis. My research exploits the advantages conferred by droplet microfluidics over conventional technologies and other microfluidics techniques in terms of automation, throughput and combinatorial power for the manipulation and analysis of single-cells.
Bioengineering Building - Room 107
Summary : Our research interests are bone adaptation, mechanotransduction and osteoimmunology in normal and pathological conditions. With a particular focus on the bone marrow stem cell environment, our lab is currently using a murine model of diet-induced obesity to study how obesity affects the bone quality and quantity, as well as the immune system. This study provides insights into the relationship between an increasing adipose burden on phenotypic and dysfunctional changes in bone marrow stem cell population, immune cells and the overall health (e.g., glucose intolerance in type 2 diabetes) during obesity. More interestingly, our study showed that mechanical signals can be harnessed to mitigate these adverse effects by normalizing the hematopoietic stem cell differentiation pathways, implicating the potential of using a non-invasive, non-pharmacological means to treat consequences of obesity.
Health Sciences Tower 16-060
Summary : Our laboratory focuses on the design and development of bioactive peptides and 3-D complex extracellular matrices (ECM) that will enhance soft tissue repair and regeneration. Peptides are assayed for biological activity in vitro and in vivo for their ability to protect tissue cells and organs from injury, stimulate tissue cell migration and proliferation and modulate stem cell and tissue cell differentiation. The ECM constructs tethered with bioactive peptides are analyzed for their physical, chemical and immunologic properties by such modalities as goniometry for hydrophilicity, static and dynamic stress and strain for viscolastic material properties, atomic force microscopy for Young's elastic moduli and surface topography; HPLC, mass spectroscopy, gel permeation chromatography and gel electrophoresis for chemical analysis; and fluorescence immunoassays for immunologic epitope mapping. In addition, cell interactions with the 3-D ECM constructs are examined at the transcriptional, protein and functional level as judged by real-time PCR, DNA microarray analyses, Western blots, proteomics, quantitative fluorescence microscopy, and cell viability, migration and proliferation assays. Special in vitro systems have been created to quantify sprout angiogenesis, epithelial sheet migration and neurite axon extension. Bioactive peptides and engineered ECM containing peptide biomimetics will also be tested in a variety of animal models and hopefully enter into clinical trials. This robust array of bioactive peptides and 3-D ECM constructs will provide new therapies for soft tissue injury and disease.
Summary : The primary role of this laboratory is to study basic physiological flow phenomena, both experimentally and numerically, as well as cellular and tissue engineering as applied to the vascular system. and to suggest ways of improving the functioning of cells, tissues and organs in the body. These physiological flows include blood flow in the heart, blood flow in arteries, veins and the microcirculation, air flow in the respiratory airways, and urine flow in the kidney and urethra. This laboratory simulates systems through the use of computers, assisting life scientists to better understand physiological functions without having to rely entirely on living systems as experimental models. The use of mathematical analysis helps minimize animal experimentation. Other projects are the investigation of hemodynamics as a regulator of vascular biology, the mathematical modeling of the dynamic response of mammalian cells, the role of flow and the associated shear stress on vascular endothelial biology, prosthetic circulatory devices and the tissue engineering of blood vessel substitutes. The laboratory is also engaged in the evaluation of critical conditions that lead to failure of biological organs, such as the heart and the coronary circulation, failure of circulatory prosthetic devices as stents, heart valves and grafts. To facilitate in vitro and in vivo studies, the laboratory develops new investigative techniques, noninvasive diagnostic methods, and advance, multi-dimensional numerical modeling.
Bioengineering Building - Room G19
Associate Professor & Undergraduate Program Director
Summary : Our emerging understanding of oxygen delivery to the tissues is that the blood flow within the smallest arterioles is tightly organized within repeating networks across the tissue. Central to this new paradigm are the concepts of vascular communication between the beginning and end of the network (via gap junctions), and its relation to flow sensing by the vascular endothelium. Our work has shown that different types of microvascular flow patterns can be triggered by direct stimulation of the focal adhesions (alpha-v-beta-3 integrins, i.e., wound healing), compared to adenosine (i.e., metabolic change), compared to nitric oxide (i.e., inflammation), hence we can control the flow patterns. Among the goals of this work are in vitro construction of transplantable microvascular networks, using bionanotechnology to create the sturdy scaffolding, and verification of nanofabricated drug delivery units within the vasculature. To this end, equally important are mechanotransduction of the physical forces associated with flow change (i.e., wall shear stress), the pharmacologic signal transduction systems involved (which guide drug discovery and intervention), and the molecular basis for the committed step that ensures healthy flow delivery. Our work employs computational modeling of the fluid mechanics, the physiology of arteriolar network blood flow (in vivo and in vitro), and precise genomic manipulation of key proteins in healthy and vascular disease states.
Bioengineering Building - Room 213
Summary : Research in this laboratory focuses on the identification of precise parameters that define skeletal tissue quantity and quality and their perturbation to applied physical stimuli. To this end, state of the art imaging techniques (e.g., microCT or synchrotron infrared spectroscopy) are combined with molecular (e.g., RT-PCR), genetic (e.g., QTL), and engineering techniques (e.g., finite element modeling) to determine genes, molecules, forces, as well as chemical and structural matrix properties. An example for a recent study includes the demonstration that extremely small amplitude oscillatory motions (~ 100µm), inducing negligible deformation in the matrix, can serve as an anabolic stimulus to osteoblasts in vivo, producing a structure that is mechanical stronger and more efficient to withstand forces. Recent results also indicate that there is not only a genetic basis for bone architecture, but also that the sensitivity of bone tissue to both anabolic and catabolic stimuli is influenced by subtle genetic variations. The identification of the specific chromosomal regions that modulate this differential sensitivity is in progress. Clinically, our studies may lead to the development of effective prophylaxes and interventions for osteoporosis, without side-effects and tailored towards the genetic make-up of an individual.
Health Sciences Tower 12-080
Summary : I believe that the role of biomedical engineers is to help nature help itself. My research interests revolve around hemodynamics. This includes not only the exploration of what is, but also create what does not exist. Our laboratory is involved in the study of blood flow to the brain and the creation of therapeutic devices both retractable and implantable to restore blood flow to normal physiological conditions. Some example include the analysis of blood flow from radiographic images, the application of mathematical tools to simulate blood flow in vasculature of interest, creation of silicone replicas of blood vessels both with and without pathologies for both elucidation of flow within and for the testing of new tools for blood flow restoration and navigation of access tools. Coils for the treatment of brain aneurysms and flow diverters are examples of mechanical devices that have been investigated extensively in our laboratory. Histoacryl, the predecessor of NBCA and Onyx for the treatment of arteriovenous malformation have all been investigated extensively in our lab.
Bioengineering Building - Room G09
Summary : Research in our lab focuses on the embedded systems and high performance computing technologies in biomedical applications. Research projects have covered a vast range from the wearable wireless infant monitor for the prevention of sudden infant death syndrome to ultrasound scanning imaging device for the assessment of bone properties. We adopted the latest technologies in embedded system design and established own platforms for the medical device prototyping to facilitate the transition of intellectual properties from bench side to bed side. We are capable of building miniaturized medical devices using microcontroller based design and integrating large sophisticated devices using off shelf components. We specialize in FPGA technology for our HPC research project because it offers the flexibility of hardware configuration that also benefits the data acquisition and control aspects in the projects.
Bioengineering Building - Room 215
Summary : Early diagnostic of osteoporosis allows for accurate prediction of fracture risk and effective options for early treatment of the bone disease. A new ultrasound technology, based on focused transmission and reception of the acoustic signal, has been developed by Dr. Qin and his team which represents the early stages of development of a unique diagnostic tool for the measure of both bone quantity (density) and quality (strength). These data show a strong correlation between non-invasive ultrasonic prediction and micro-CT determined bone mineral density (r>0.9), and significant correlation between ultrasound and bone stiffness (r>0.8). Considering the ease of use, the non-invasive, non-radiation based signal, and the accuracy of the device, this work opens an entirely new avenue for the early diagnosis of metabolic bone diseases.
Bioengineering Building - Room 101
Associate Professor & Graduate Program Director
Summary : The goal of our lab is to 1) develop a biomimetic three-dimensional tissue engineering scaffolds that promotes microvascular blood vessel growth and 2) elucidate mechanisms that induce cardiovascular disease responses. The need for new tissue engineering scaffolds that promote microvascular growth arises due to diffusion limitations through biological tissue, which at best is approximately 100 microns. With a method to fabricate patent vascular networks ex vivo, it is possible that large scale tissue engineering applications can be realized or the healing of chronic wounds can be accelerated. Our work has identified a number of viable scaffolds that can promote vascular network growth. Additionally, more recent work has focused on identifying scaffold fabrication techniques that can form viable scaffolds for microvascular applications. Cardiovascular diseases remain the leading cause of death in the Western world. Due to this, it is salient that an understanding of disease progression is found. We aim to understand how combinations of cardiovascular disease risk factors interact to induce, accelerate, enhance or inhibit cardiovascular disease processes. Our main focus is on advanced glycation end products (diabetes), tobacco smoke and disturbed wall shear stress. We focus on platelets, endothelial cells and their interactions for all projects in our lab.
Bioengineering Building - Room 217A
Distinguished Professor & Chair
Summary : Encouraging results show that the application of extremely low level strains to animals and humans will increase bone formation, and thus may represent the much sought after "anabolic" stimulus in bone. More than 15 years of research into non-invasive, non-pharmacological intervention to control osteoporosis, was referenced in Dr. Rubin's paper published in the journal Nature (August 9, 2001; 412:603-604). Dr. Rubin's studies suggest that gentle vibrations on a regular basis will help strengthen the bones in osteoporosis sufferers and increase bone formation. In his study, adult female sheep treated with gentle vibration to their hind legs for 20 minutes daily showed almost 35% more bone density. Clinical trials have been completed on post-menopausal women, children with cerebral palsy, and young women with osteoporosis, all with encouraging results. In expanding the research platform into other physiologic systems, current work demonstrates that these low-level signals influence mesenchymal stem cell differentiation, such that their path to adipocytes is suppressed, and markedly reduces adipose tissue.
Professor and Associate Director
Summary : The Simmerling lab at Stony Brook University carries out research in the area of computational structural biology. In particular, the lab focuses on understanding how dynamic structural changes are involved in the behavior of biomoleculs such as proteins and nucleic acids.
Bioengineering Building - Room 115
Summary : Our laboratory seeks to integrate advances in nanoscience and technology with the biological sciences and clinical medicine to achieve significant advances in simultaneous molecular diagnostics and therapeutics (theragnosis), drug delivery, and bioengineering. Towards these ends, our research interests involve a multidisciplinary approach for the development of functional (electronic, optical, magnetic, or structural) bionanosystems as contrast agents for molecular imaging, as carriers for drug delivery, and as structural scaffolds for tissue engineering. Our current projects capitalize on the unique properties of carbon nanobiomaterials to develop a) advanced contrast agents (CAs) for molecular magnetic resonance imaging (MRI), b) nanocomposites to improve the physical and biological (osteoconduction and osteoinduction) properties of polymer scaffolds for bone tissue engineering and c) non-viral vectors for gene transfection. We have exploited the potential of Gd-based carbon nanostructures: Gd@C60 metallofullerenes (gadofullerenes) and Gd@Ultrashort-tubes (gadonanotubes) as a new generation of advanced CAs for MRI and shown them to have efficacies up to 100 times greater than current clinical CAs. Our recent studies show that they are particularly well suited for passive (magnetic labels for cellular MRI) and active (pH sensitive probes for cancer detection) MRI-based Molecular Imaging. Single-walled carbon nanotubes (SWNTs) have been proposed as the ideal foundation for the next generation of materials due to their excellent mechanical properties. We have dispersed SWNTs and ultra short SWNTs into fumarate-based polymers to form nanocomposite scaffolds that exhibit mechanical properties far superior to the polymers alone and are osteoconductive as well osteoinductive. Our research work involves material synthesis techniques, physico-chemical characterization techniques, tissue culture and in vivo studies.
Bioengineering Building - Room G13
Summary : Nature's ability to assemble simple molecular building blocks into highly ordered materials, such as those found in cell membranes, cell nuclei, cytoskeleton, cartilage, or bone presents many fascinating and unanswered questions. We are interested in how to tune the interactions of water-soluble building blocks so as to induce their self-assembly into useful microstructures much needed for the next generation of controlled drug delivery, biosensors and DNA sequencing applications. In particular, we are working on long-range ordered polyelectrolyte-surfactant microemulsions that are used as templates for solid nanoporous materials using polymerization and/or cross-linking strategies. Such materials, because of their well-ordered porous structure, will allow more efficient molecular separation and drug delivery. In addition, we are developing biosensors that are based on biopolymer chiral liquid crystals and quantum dot colloidal crystals. In both cases the softness of the systems allows the induction of a strong optical response to external stimuli. Such sensors should be able to quantitatively detect and measure analyte concentrations at hormonal levels.
Bioengineering Building - Room 109
Summary : Cardiovascular disease is the leading cause of death in the United Sates, and coronary artery disease is the most common type of cardiovascular disease. Shear stress induced by blood flow plays an important role in the initiation and development of atherosclerosis, the major reason for coronary artery disease. Circulating platelets and vascular endothelial cells are very sensitive to their mechanical environment; any change can affect their functions and interactions significantly. My major research interest is to investigate how altered blood flow and stress distribution affect platelet and endothelial cell behavior and lead to cardiovascular disease initiation. Computational fluid dynamics modeling, along with in vitro and ex vivo experiments, are carried out to study platelet and endothelial cell responses under physiologically relevant dynamic conditions. Biomarkers associated with platelet and endothelial cell activation are of special interest to us. We also work on numerical models to describe platelet coagulation kinetics and platelet adhesion to injured blood vessel wall under dynamic flow conditions.