Transdermal H2S Sensing Device for Monitoring Peripheral Artery Disease

Project Summary Abstract Peripheral artery diseasePADand small vessel diseaseSVDare the consequences of damage to the endothelial cells that line all vesselsboth leading to inadequate skin perfusion and end organ and limb damageIt is prevalent in diabetic patient population in which nearlysuffers from PAD and SVDThe proposed effort addresses an unmet need for early diagnosis of PAD and SVD in this high risk groupA number of studies describe the difficulties in diagnosing arterial disease in diabetic patientsincluding the high risk of vascular calcificationwhich leads to overestimates of limb blood flow by ABI measurements and missed diagnosis of partial occlusionsDespite the important role of skin perfusionit is seldom detected or even tested for in its early stages due to the lack of routine screening protocols and the requirement for expensive diagnostic equipment and trained techniciansThis highlights the significant opportunity for development of a simpleinexpensive protocol to routinely screen subjects with skin perfusion risk factors early enough that would allow more effective treatment options for diabetic retinopathyneuropathylimb ischemiacerebral vascular diseasecoronary vascular disease and nephropathyCreating a way to detect vascular disease at a point where changes are reversible willimprove patient quality of life by delaying or preventing the development of end organ damageanddecrease patient care costsThe proposed protocol utilizes hydrogen sulfideH Sa newly described endothelium derived vasodilator that decreases with the onset of endothelial diseasethe underlying cause of most PAD and SVD casesFurthermorenormal levels of H S are beneficial for preventing endothelial dysfunctionfor improving recovery from muscle ischemia and in mitigating damage from myocardial infarctionThere is currently no non invasive method to accurately measure plasma H S and the few existing techniques require specialized equipment and skilled techniciansOur proposed technologythe transdermal gasotransmitter sensorTAGSemploys an innovative gas phase detector which noninvasively measures plasma levels of H SIn the STTR Phase I feasibility studythe Exhalix and University of New Mexico team developed and used a laboratory version of TAGS to perform preliminary animal studies in which physiologically relevant normal and reduced plasma levels of H S were transdermally detected in male Sprague Dawley ratsDuring the proposed SBIR Phase II renewal studieswe intend to continue the development of advanced prototypes of TAGSThese prototypes will be verified and validated across a broad cross section of subjectsincluding healthy and diabetic animal and human subjects of both sexesin collaboration with experienced physician scientists at the School of Medicine and the Center for Translational and Clinical SciencesWe anticipate that successful development and validation of TAGS during Phase II will lead to Phase IIB clinical studies and commercialization of the technology Project Narrative Peripheral artery diseasePADand small vessel diseaseSVDare vascular disorders caused by endothelial dysfunction which affect more thanmillion Americans over the age ofEarly diagnosis and treatment of PAD and SVDparticularly targeting the diabetic patient populationcan save limbslivesand billions of dollars in healthcare costs and improve quality of life for these patientsThis proposal addresses the need for development of a more accessibleuser friendlyand inexpensive skin perfusion assessment technique for early detection of PAD and SVD