Portable Breast Cancer Screener
The Department of Surgery is collaborating with the Departments of Material Science and Engineering, Pathology and Laboratory Sciences, and the School of Biomedical Engineering in the development of a low-cost portable breast cancer screening device. Breast cancers are stiffer than normal breast tissues and the differences in stiffness between cancer and normal tissues can be exploited for early detection. We have developed a piezoelectric-based tissue stiffness measurement/detecting system which we have named the Piezoelectric Finger (PEF). The PEF can measure both the elastic modulus (E) (the stiffness of tissue under compression) and shear modulus (G) (the stiffness of tissue under shear) with great precision. Using our prototype device and ex vivo breast samples we showed that the contrast between the E or G of abnormal breast tissues such as carcinoma in situ (CIS) and invasive carcinoma (IC) versus that of normal breast tissues consisting of glands and fat was 3-5 fold for women of all age groups. This technology is targeted for developing countries which do not have the resources to implement programs similar to the mammography based screening program available in the United States.
Participating faculty:
Wan Shih, Ph.D shihwy@drexel.edu
Wei-Heng Shih, Ph.D. shihwh@drexel.edu
Ari Brooks, M.D. ari.brooks@drexelmed.edu
Vanlila Swami, M.D. vanlila.swami@drexelmed.edu
Additional information is available at http://sensor.materials.drexel.edu/
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Quantum Dots for Tumor Margin Detection
Breast cancer is increasingly being diagnosed at an early stage allowing treatment with breast conserving surgery. After excision of the tumor it is important to determine that the tumor margin is clear of any cancer cells. If tests determine that the margin is not clear, the patient must return for re-excision. Currently there is no reliable method to assess margins intra-operatively.
The development of a reliable intra-operative test that allows the surgeon to test for residual cancer cells rapidly after the initial excision can allow the re-excision to occur immediately during the initial surgery reducing overall treatment costs and pain and inconvenience to the patient. Quantum Dots (QDs) are nanocrystals that fluoresce over a long period of time without photobleaching. QDs are brighter and therefore more sensitive than traditional fluorescent molecules, permitting imaging of far fewer cells. Dr. Wei-Heng Shih and Dr. Wan Shih have developed an approach for making highly luminescent aqueous QDs using an environmentally friendly aqueous process from which QDs can be directly conjugated for bioimaging. Through conjugation with appropriate antibodies these QDs can be used to image cancerous cells in excised tissues to allow timely examination of margin clearance. The intensity of the photoluminescence (PL) will indicate if cancer cells are on the excised tissue surface.
Participating faculty:
Wan Shih, Ph.D shihwy@drexel.edu
Wei-Heng Shih, Ph.D. shihwh@drexel.edu
Ari Brooks, M.D. ari.brooks@drexelmed.edu
Vanlila Swami, M.D. vanlila.swami@drexelmed.edu
Additional information is available at http://sensor.materials.drexel.edu/
Wound monitoring, therapy, and regenerative medicine
Dr. Michael Weingarten is medical director of the Drexel Comprehensive Wound Healing Program and is involved with several research projects related to wound care.
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Near Infrared Wound Monitor
Wound assessment is highly subjective and can be misleading. The predominant metric to assess wound healing is a decrease in wound size. However, it has be shown in the scientific literature that shrinkage in wound size only has a 58% correlation to actual healing. Optical properties of wound tissue and surrounding environment reflect metabolic activity and correlate with wound healing. Using a Near Infrared Spectroscopy (NIRS) developed by the Drexel University School of Biomedical Engineering, we have discovered that the time course of the absolute amount of oxygenated hemoglobin in tissue is a strong indicator of wound healing progress. Based on measurements of the oxygenated and deoxygenated hemoglobin using the NIRS device, a wound healing index is computed which provides the physician with the status of healing in the wound. This device is currently undergoing human subject testing and technical refinement.
Participating faculty:
Elizabeth Papazoglou, Ph.D. esp25@drexel.edu
Michael Weingarten, M.D. michael.weingarten@drexelmed.edu
Bioactive Alimentary Protein-based Scaffolds (APS) for Wound Healing and Regenerative Medicine
There is an unmet clinical need for simple, first-response bioactive wound dressings that would help reduce the morbidity and mortality from severe injury to the skin. Our long-term goal is to develop and commercialize a novel bioactive engineered acellular wound dressing, "Alimentary Protein Based Scaffolds" (APS), which will have multiple applications for wound healing treatments and regenerative medicine. Our scaffold is produced by electrospinning of a soybean protein base. Our initial experiments involve demonstrating that the APS will accelerate wound healing in an animal model. We envisage that APS, packaged as an acellular scaffold, will be sterile, portable, and readily available, with an extended shelf life.
Participating faculty:
Peter Lelkes, Ph.D. pilelkes@drexel.edu
Elizabeth Papazoglou ,Ph.D. esp25@drexel.edu
Michael Weingarten, M.D. michael.weingarten@drexelmed.edu
Additional information is available at http://www.biomed.drexel.edu/faculty_pages/lelkes/index.html
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Acousto-optic Theragnostic Approach for Chronic Wound Management
The long-term objective of our proposed program is to develop a non-invasive chronic wound treatment that combines optic and acoustic modalities in a synergistic way. This theragnostic, i.e., thera(peutic) and (dia)gnostic technology, merging a non-invasive ultrasound therapy with Near Infrared (NIR) diagnostic monitoring, will allow a wound care provider to prescribe low frequency ultrasound therapy through a “Band-Aid®”-like wearable patch, assess the status of wound healing with digital imaging and NIR, and adjust the ultrasound parameters as necessary. The treatment considered here involves exposure of the wound to non-invasive low (20-100 kHz) frequency ultrasound energy with periodic real-time digital and near infrared (NIR) monitoring of tissue optical properties related to wound healing parameters. Thus, in vivo acquired diagnostic information provided by an optic sensor will be combined with therapy and used to direct and optimize wound healing treatment. Our ultimate goal is to develop a sterile, patient-friendly patch containing an ultrasound applicator and associated electronic controls that could be directly applied by a patient to the wound. This wearable patch will allow for frequent (daily or even multiple exposures per day) application of the ultrasound therapy without a return of the patient to the clinic and will significantly increase patient compliance with the therapy. In order to accomplish this goal, we will establish the optimal ultrasound exposure parameters that will serve as the basis for the prototype “Band-Aid®”-like wearable ultrasound applicator.
Participating faculty:
Peter Lewin, Phd.D. lewin@ece.drexel.edu
Elizabeth Papazoglou, Ph.D. esp25@drexel.edu
Michael Weingarten, M.D. michael.weingarten@drexelmed.edu
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Directed Drug Delivery
Surgical procedures that require anastomosis of small lumen structures such as the common bile duct, ureters, and small blood vessels have not benefited from the reliability and ease of surgical stapling. Use of surgical staples for small structures is limited by small structure size and susceptibility to ill effects from scarring at the tissue joint.
We are working to create a new tissue-joining device that will improve on existing staples, including a smaller version for use with small structures. This new staple will be composed of two parts: a rivet with a hollow lumen for flow of bodily fluids and a ring to secure the approximated tissues. Our current research is focusing on the ring. We are developing a biocompatible ring that will degrade and simultaneously deliver drugs.
Improving the speed, accuracy, and effectiveness of procedures, while lowering the morbidity and mortality rates of surgical interventions, is the overall goal of our laboratory. The objective of this project is to develop a new staple for small lumen structures fabricated from an FDA-approved biocompatible, biodegradable polymer that delivers bioactive agents to improve healing. A miniaturized surgical staple that allows delicate structures to be joined safely while maintaining vessel patency will have broad applications in surgery.
More information about directed drug delivery research is available here.
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Magnetizable Stents for Drug Delivery
Dr. Boris Polyak (Surgery/School of Biomedical Engineering), Dr. Gary Friedman (Electrical and Computer Engineering), Dr. Kenneth Barbee (School of Biomedical Engineering), and Dr. Benjamin Yellen (Duke University Department of Mechanical Engineering and Materials), are developing a minimally invasive, targeted drug-delivery system that uses magnetic implants and magnetic nanoparticles to administer repeatable, patient-specific dosages of therapeutic agents to specific sites in the human body. In vivo trials are conducted under the supervision of Dr. Ari Brooks, M.D. (Surgery). Numerous graduate students and residents from the laboratories of Polyak, Friedman, Barbee, Yellen, and Brooks are participating in different aspects of the project. The researchers on the team specialize in the fields of magnetism, fluids, cardiovascular biomechanics, oncology, and surgery
In many cases, currently available drug delivery vehicles (polymer spheres, liposomes, or hydrogels, for instance) do not have a mechanism for localization that allows delivery of high concentrations of drugs with minimally invasive techniques. This is especially true when repeat dosing is required. Ultrasound-mediated delivery shows promise for regional drug delivery, but lacks the pin point accuracy needed for delivery to vascular walls and isolated tumors. The magnetic drug delivery system proposed herein overcomes many of these difficulties and provides a method for concentrating drugs at selected sites in the body with minimal stress on the patient, with much higher dosages than could be accomplished via systemic drug administration, and without the fear of toxicity. The first objective of this project is the prevention of coronary restenosis by adapting this system for use in coronary stents, but if successful, the technology can be expanded to numerous applications ranging from cancer therapy to stem cell delivery. In addition, the incorporation of magnetism into the delivery of the various carriers mentioned above may increase their efficacy and expedite their clinical implementation.
Our central hypothesis is that when implanted in vivo, an intra-vascular stent plated with small magnetic features or composed of a weakly magnetic alloy can attract large numbers of injected superparamagnetic particles under the application of a modest external magnetic field. This procedure is minimally invasive and allows repeat dosing. Furthermore, the therapeutic agent and/or the delivery vehicle can be varied. Concurrent ex vivo and in vivo studies have examined a method for targeted drug delivery by applying high magnetic field gradients within the body to an injected superparamagnetic colloidal fluid carrying a drug, with the aid of modest uniform magnetic field. The design is ideally suited for endovascular implants, such as coronary stents, or other implants with primary functions independent of local drug delivery.
We encourage interested post-doctoral candidates, residents, and faculty to contact us to share input, inquire about opportunities for collaboration, as well opportunities to join our team.
 
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