Research Project: Hydrogel Culture Environments for Regenerative Medicine Applications
We can interrogate and take advantage of the critical interactions between cells and extracellular matrix (ECM) to create bioactive materials capable of controlling cell function and tissue evolution. To determine the requirements of the microenvironment, we utilize hydrogels easily modified with respect to mechanical integrity, adhesive peptides, ECM molecules, degradability, and incorporation of drugs, to direct cellular differentiation through a variety of mechanisms.In particular, we are interested in utilizing hydrogel microenvironments to direct encapsulated mesenchymal stem cell (adult stem cell) function for applications in musculoskeletal tissue engineering. A thorough understanding of how material properties effect cell differentiation and tissue evolution is essential to tailor ‘instructive materials’ to direct cell function.Targeted polymer therapeutics to overcome drug delivery barriersConventional small molecule drugs and large macromolecular drugs have significant and distinctly different delivery barriers. For example, small molecule drugs, such as the chemotherapeutic doxorubicin, is highly hydrophobic, thus administration requires toxic cosolvents to aid blood solubility. Macromolecular drugs, on the other hand, suffer from enzymatic degradation and inactivation, difficulty in targeting to the appropriate cells and transversing the cell membrane, and often become degraded intracellularly once endocytosed. We are investigating polymer-drug complexes or polymer-drug conjugates to overcome these barriers and modulate drug delivery.
Musculoskeletal disorders affect roughly 50% of all adults in the United States and cost the nation nearly 1 trillion dollars a year in lost wages. One of the research goals of the Buckley lab is to understand and develop exercise-based non-operative treatments for painful musculoskeletal diseases including tendinopathy and osteoarthritis. Our primary approach is to apply controlled, time-dependent mechanical deformation to excised specimens of cartilage and tendon in specialized microscope-mounted devices. These devices are perfused with culture medium, allowing cells within the tissue to stay alive over extended time periods and enabling investigation of the cellular response to specific forms of mechanical deformation (i.e., exercise). In one specific project, we are obtaining specimens of tendon affected by insertional Achilles tendinopathy (IAT) following debridement surgery and assessing whether mechanical stimulation can reverse IAT-induced structural changes in vitro. The findings of this experiment will directly guide a parallel clinical study investigating the efficacy of exercise for treating IAT in vivo.
We combine neurophysiological, behavioral, and computational modeling techniques towards our goal of understanding neural mechanisms underlying the perception of complex sounds. Most of our work is focused on hearing in listeners with normal hearing ability. We are also interested in applying the results from our laboratory to the design of physiologically based signal-processing strategies to aid listeners with hearing loss.
We are currently studying two specific problems:
These problems are of interest because they are tasks at which the healthy auditory system excels, but they are situations that can present great difficulty for listeners with hearing loss. We study the psychophysical limits of ability in these tasks, and we also study the neural coding and processing of these sounds using stimuli matched to those of our behavioral studies.
Computational modeling helps bridge the gap between our behavioral and physiological studies. For example, using computational models derived from neural population recordings, we make predictions of behavioral abilities that can be directly compared to actual behavioral results. The cues and mechanisms used by our computational models can be manipulated to test different hypotheses for neural coding and processing.
By identifying the cues involved in the detection of signals in noise and fluctuations of signals, our goal is to direct novel strategies for signal processors to preserve, restore, or enhance these cues for listeners with hearing loss.
Research Project #1: Biomedical Optics for Breast Cancer Detection and Therapy Monitoring
The overall goals of this project in Professor Choe's laboratory are to assess and improve the capabilities of diffuse optical technology in
breast cancer therapy monitoring and detection. In clinical measurements of human breasts with tumor, we focus on identifying functional parameters measurable with diffuse optics, which can serve as early indicators of therapy efficacy. Using a preclinical animal model, we study the metabolic mechanism of varied responses to therapy seen in the clinic, and investigate new therapeutic drugs and interventions. Also, we explore new functional and metabolic parameters (e.g. glucose metabolism) accessible through near-infrared fluorescent optical agents. The students will have opportunities to participate in various aspects of research: instrumentation construction and characterization, data analysis algorithm development, preclinical experiments, and/or clinical experiments.
Research Project #2: Diffuse Optical Imaging for Non-Invasive Deep Tissue Monitoring of Bone Graft Vascularization
Achieving effective revascularization is critical for successful integration of bone graft. While various tissue engineering strategies have been proposed and tested, most revascularization assessment is performed using methods requiring destruction/sacrifice of samples. Diffuse optical imaging can quantify hemodynamic parameters of deep-tissue in vivo samples non-invasively, allowing longitudinal monitoring of bone graft vascularization process. The project will focus on development of imaging methods for in vivo preclinical experiments, which will give students exposure to various aspects of research: instrumentation construction and characterization, data analysis algorithm development, preclinical experiments, and collaboration with experts in tissue engineering field.
Research Project: Developing the Next Generation of Non-Contact Physiological Monitoring Devices
Patient monitoring systems are undergoing fast growth. An estimated 19% increase between 2011 and 2012 for the US market has topped $10.6 Billion in 2012. Contactless methods of extracting vital signs in the form of heart rate and breathing rate using video cameras and ambient light received considerable attention in recent years, yet their utility to reliably solve clinical and every-day life challenges has not been demonstrated yet. To date, contactless monitoring of patients or individuals during their everyday activities has been limited to smart phone application characterized by a rather low levels of accuracy and precision. Furthermore, there is crucial missing component in the current technologies of contactless monitoring of physiological signals: its ability to provide information that are relevant to the health provider i.e. blood pressure, oxygen saturation in addition to respiratory and pulse rate. We propose to build upon our recent work on emerging contactless videoplesthysmography technology and complement it with features enabling the monitoring of multiple physiological signal including blood pressure, oxygen saturation, and beat-to-beat pulses of respiration and heart rate. As part of the project goals, we will develop, test and validate a prototype of an automatic measurement system using novel hyperspectral camera equipment. The system will deliver the technologies required to provide continuous monitoring of individuals by videorecordings their face or/and hands.
Research Project: Biomedical Ultrasound
The primary goals of Professor Dalecki’s laboratory are to advance novel diagnostic ultrasound techniques, and to discover new therapeutic applications of ultrasound in medicine and biology. For this project, students will work towards developing new ultrasound technologies for the field of tissue engineering and regenerative medicine. Specifically, students will investigate the effects of ultrasound on extracellular matrix proteins and cell functions that are key for engineering artificial 3D tissues and enhancing wound repair. Students will develop skills in acoustic field calibration, signal processing, cellular and tissue preparation procedures, cell and extracellular matrix biology, and ultrasound physics. The research is highly multidisciplinary and spans the fields of biomedical ultrasound, acoustics, medical imaging, cell and tissue engineering, and biomechanics.
Research Project #1:
The overall goal of our research program is to understand the risks for musculoskeletal joint disorders. For example, we are particularly interested in the effects of gender, ethnicity, obesity, knee injuries and gait patterns in the risks for knee osteoarthritis. We use a combined approach involving gait analysis, medical imaging and computational modeling to study these effects and try to predict the clinical risk factors associated with each factor, and combinations of these factors. Students may help with image analysis to better understand the role of the meniscus in distributing loads during knee flexion, or help to develop subject-specific finite element models with meniscal injuries or partial meniscectomy. These models may be modified to consider a variety of loading conditions representing different types of activities. Our long term goal is to assist clinicians in advising their patients about appropriate exercise, activity and treatments to prevent the onset or progression of disease.
Research Project #2 (Joint Project with Prof. Geunyoung Yoon):
We are investigating the use of computational biomechanics models to study the effect of altered biomechanics due to corneal surgery. This project will explore the use of finite element models to predict the effects of laser refractive surgery on the biomechanical and optical behavior of the eye. The student will investigate the implementation of detailed geometric characteristics as well as the complex material properties of the cornea tissue in an FE model and may have the opportunity to compare computational results to experimental studies.
Research Project #1: Applications of Switchable Silicon Nanomembranes for the Controlled Release of Therapeutics
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Research Project: Measurement of Mechanical Properties of the Cochlear Partition
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Research Project: Blood Cell Bioreactor
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Research Project #1: Myopia Progression: Role of Optical Quality of the Eye
Myopia is one of the leading causes of visual impairment worldwide and is linked to severe eye diseases such as maculopathy, retinal detachment and glaucoma. The overall prevalence of myopia has increased substantially in recent years. With higher levels of myopia becoming a significant public health concern, it is of crucial importance to find effective treatments to slow myopic progression in children. Among many potential factors such as genetics, visual environment, accommodative ability, our research focus is on understanding how optical quality of the eye impacts on the progression of myopia. Our hypothesis is that non-optimal ocular optics e.g. wavefront aberration can cause myopia and the progression can be controlled by optimizing image quality across a wide range of retinal eccentricity. A high-resolution ocular wavefront sensing and advanced vision correction technology will be used to quantify an aberration profile and its impact on retinal image quality in myopic eyes compared to normal eyes. It is also our interest to perform a longitudinal study where the changes in the optical profile of the eye over a long period of time will be determined to investigate their relationship with refractive error development.
Research Project #2: Multimodal Tear Imaging for Dry Eye Research
Dry eye is a multifactorial disease of the ocular surface and tears, resulting in symptoms of discomfort, visual disturbance, and instability of the tear film with the potential for ocular surface damage. It is recognized as one of the most common ocular disorders affecting many patients aged 50 years and older. Current clinical measurement techniques used for dry eye evaluation is a critical barrier to effectively diagnosing and treating the disease because they are often invasive and ineffective to comprehend the complex interplay between tear film, ocular surface and environmental variations. We use the state-of-art multimodal tear imaging technology developed in the laboratory for the accurate and objective assessment of the tear parameters and their response to controlled environmental changes. The multimodal tear imaging technology such as tear surface topography/wavefront sensor, ocular surface optical coherence tomography, imaging ellipsometer and thermal imaging will be used to characterize the tear. The project also involves development of various computer algorithms to analyze tear images automatically.