Novel Approach to Lactate Sensing Diabetes Pre-screening Tool

Novel Approach to Lactate SensingDiabetes Pre-screening Tool Christine Zhang, Stephanie Wu, Joseph Sun, WernOng, Toby Li

Problem Statement No Type II Diabetes Pre-screening device exists in the market To address this need, we will create a hydrogel based lactate sensor where lactate level predicts probability of Diabetes II onset

Diabetes Chronic illness characterized by high blood sugar Type II diabetes is caused by insufficient insulin levels, most often because the body has become resistant to insulin Insulin is a hormone produced by the pancreas to control blood sugar

Indicators/Complications • Heart Disease/Stroke • High Blood Pressure • Blindness • Kidney Disease • Nervous System Disease (Neuropathy) • Amputation • Age • Ethnicity • Weight • Family History • Other Symptoms • Infections • Vision • Slow to heal

Current Testing Methods • 3 pre-diabetes tests • A1C test • Fasting plasma glucose test • Oral glucose tolerance test • Lactate Sensor • Simple • More accessible

Diabetes (I & II) • Prevalence • 25.8 million people (8.3%) U.S. population • 18.8 million people diagnosed • 7.0 million people undiagnosed • 170 million people worldwide • 79 million Pre-diabetes (U.S.) • 1.9 million cases of diabetes diagnosed in 2010 (U.S.) • 300 million people by year 2025

Market Potential • 174 Billion: Total Costs of Diagnosed Diabetes (2007) • 116 Billion: Direct Medical Costs • 58 Billion: Indirect Costs • Medical expenditure of diabetics 2.3X higher than non-diabetics

Performance Criteria • Sense over a large range of lactate levels • 0.15 – 0.3 mmol • Work in a timely manner • <24 hrs. • FPG  32 hrs • OGTT  10 hrs • Low cost • < $1 dollar • Glucose Monitors  $10 • Roche diagnostics  $190 • Accuracy • 60%

Primary Objective • Develop lactate sensitive screening device for pre-diabetes screening • Using lactate sensitive hydrogels • Measure volumetric change (directional swelling) • Correlate volume change to saliva lactate Levels • Predict probability of developing type II diabetes

Solution Description Tube filled with lactate sensitive hydrogel polymer Exposure to saliva lactate causes directional swelling of hydrogel polymer Volumetric change to saliva lactate concentration correlated to blood lactate levels Correlation of lactate concentration to development of type-2 diabetes

Volume Change Hydrogel

Supporting Figures Probability curve

Goals • Hygienic • Non-Invasive • Disposable • Uniform • Cheap < $10 • Easy To Use • Accurate

Factors • Polymer Ratio (More DMAEMA = more pH sensitive) • Number of Tubes per batch • Concentration of Lactate Oxidase • [Lactate] • Capillary diameter

System and Environment Clinical Setting Temperature Self Testing Lifestyle Change Lactate Conc. Volumetric Change Saliva Sample Lactate Sensor Diabetes Prediction Water Blood Test pH See Physician Proteins

Experiment Block Diagram

Performance

Performance (Cont.)

Conclusion Hygienic Non-Invasive Disposable Uniform Cheap $0.23/tube

Informal Observations Hard to measure volume change Hard to control directional swelling Hydrogel polymer not very sensitive to small lactate concentrations Gradual volumetric change not immediate (hrs) Air bubbles Un-uniform distribution of lactate oxidase

Recommendations Colorimetric Assay – Gradient of color change for more specific lactate readings Digital Readout – More accurate saliva lactate readings Testing in a public health application – test viability in large clinical settings (ie. Schools, businesses, clinics)

References http://www.who.int/diabetes/publications/en/screening_mnc03.pdf

Novel Approach to Lactate Sensing Diabetes Pre-screening Tool