Stimulation, Recording Potential and Antimicrobial Medical Catheter Coatings

Biocompatibility of electrodes for stimulation are difficult to maintain homeostasis. Noble metal stimulating electrodes which are normally biocompatible on keratinized tissue become very non-biocompatible when they are interfaced with nonkeratinized tissue in an area such as the oral cavity. Composite electrodes have been made biocompatible in the oral cavity even at current densities larger than 1 μA/mm2. Electrodes used in potential readings require that the anodic and cathodic polarization remain minimal. Silver-silver chloride electrodes are minimal. Silver-silver chloride electrodes are not always reversible. The range of pH, voltages and current densities when silver-silver chloride are not reversible are presented. Recently at Drexel University reliable silver coatings inside and outside of medical catheters have been fabricated to act as antimicrobial to a variety of bacteria. Noble and nonnoble metals have been combined in coatings with silver to enhance the antimicrobial action

Targeting in situ and imaging multiple inflammatory biomarkers with quantum dots in DSS model of colitis

Poster presented at Biomedical Technology Showcase 2006, Philadelphia, PA. Retrieved 18 Aug 2006 from http://www.biomed.drexel.edu/new04/Content/Biomed_Tech_Showcase/Poster_Presentations/Papazoglou_6.pdf.Inflammatory Bowel Disease affects nearly 1.5 million people. Currently, there are no efficient and reliable methods to quantify the degree of inflammation in these patients. The objective here was to image and quantify in an experimental model of colitis, MPO, IL1_ and TNF_ (proinflammatory cytokines) using Quantum Dots (QDs) conjugated with specific antibodies. The resulting fluorescence intensity was then used as a measure of concentration of MPO and in turn inflammation. The fluorescent images obtained from animals showed sequential increase in fluorescence intensity of MPO correlating (R = 0.96) with clinical disease. Fluorescent images also showed co-localization of all the three markers in both acute as well as chronic inflammation. These observations suggest that QD bioconjugates can be used nanotools to image biomarkers of inflammation

Portable anthrax detection system (PADS)

Poster presented at Biomedical Technology Showcase 2006, Philadelphia, PA. Retrieved 18 Aug 2006 from http://www.biomed.drexel.edu/new04/Content/Biomed_Tech_Showcase/Poster_Presentations/Lec_6.pdf.Biosensors such as the Quartz Crystal Microbalance (QCM) and micro cantilever (MC) are becoming increasingly popular in homeland security applications due to their high sensitivity. Furthermore, they can be functionalized for specific pathogens such as bacillus anthracis (anthrax) to give high selectivity. These sensing platforms are currently available, but expensive laboratory equipment is required for sample preparation, measurement and analysis. The ideal device will give accurate and repeatable results on a real-time basis using a single system that completes the entire process for use in the laboratory or field. The Portable Anthrax Detection System (PADS) has been developed to meet these requirements. It utilizes a cartridge that contains either a QCM or MC sensor. The system introduces a sample to the sensor, then measures and analyzes it for bacillus anthracis. Sensor results are quantified based on a specific algorithm for the pathogen. The PADS is user friendly, inexpensive, compact, flexible, and is currently undergoing reliability testing

A Rapid Method to Regenerate Piezoelectric Microcantilever Sensors (PEMS)

Piezoelectric microcantilever sensors (PEMS) can be sensitive tools for the detection of proteins and cells in biological fluids. However, currently available PEMS can only be used a single time or must be completely stripped and refunctionalized prior to subsequent uses. Here we report the successful use of an alternative regeneration protocol employing high salt concentrations to remove the target, leaving the functional probe immobilized on the microcantilever surface. Our model system employed the extracellular domain (ECD) of recombinant human Epidermal Growth Factor Receptor (EGFR) as the probe and anti-human EGFR polyclonal antibodies as the target. We report that high concentrations of MgCl2 dissociated polyclonal antibodies specifically bound to EGFR ECD immobilized on the sensor surface without affecting its bioactivity. This simple regeneration protocol both minimized the time required to re-conjugate the probe and preserved the density of probe immobilized on PEMS surface, yielding identical biosensor sensitivity over a series of assays

Opportunities and barriers to translating the hibernation phenotype for neurocritical care

Targeted temperature management (TTM) is standard of care for neonatal hypoxic ischemic encephalopathy (HIE). Prevention of fever, not excluding cooling core body temperature to 33°C, is standard of care for brain injury post cardiac arrest. Although TTM is beneficial, HIE and cardiac arrest still carry significant risk of death and severe disability. Mammalian hibernation is a gold standard of neuroprotective metabolic suppression, that if better understood might make TTM more accessible, improve efficacy of TTM and identify adjunctive therapies to protect and regenerate neurons after hypoxic ischemia brain injury. Hibernating species tolerate cerebral ischemia/reperfusion better than humans and better than other models of cerebral ischemia tolerance. Such tolerance limits risk of transitions into and out of hibernation torpor and suggests that a barrier to translate hibernation torpor may be human vulnerability to these transitions. At the same time, understanding how hibernating mammals protect their brains is an opportunity to identify adjunctive therapies for TTM. Here we summarize what is known about the hemodynamics of hibernation and how the hibernating brain resists injury to identify opportunities to translate these mechanisms for neurocritical care

Function brain imaging using near-infrared technology - assessing cognitive activity in real-life situations

Ieee Engineering in Medicine and Biology Magazine, 26(4), 38-46

Optical diagnosis and treatment optimization in chronic diabetic wound

Progress report presented at Biomedical Technology Showcase 2006, Philadelphia, PA. Retrieved 18 Aug 2006 from http://www.biomed.drexel.edu/new04/Content/Biomed_Tech_Showcase/ProgrReport_Presentations/Papazoglou_NIR_Wounds.pdf