The objective of this STTR proposal is to develop a 2-D diffusion point-of-care assay (POC) for B-type natriuretic peptide (BNP). The primary goal of the proposed work is to create a test format that will allow patients with chronic heart failure to quantitatively self-monitor serum levels of BNP. Determination of baseline level of BNP and changes in this level over time have prognostic utility in patients presenting with acute coronary syndromes and acute heart failure, and data suggest that monitoring levels over time may be a useful adjunct to traditional clinical evaluation by chronic monitoring of volume status in heart failure patients and potentially in guiding their treatment. While the applications of point-of-car testing of BNP in the outpatient clinic setting are obvious, quantitative devices remain cumbersome and are not well suited to patient engagement in their own monitoring and care. In this proposal, we exploit technological advances that simplify real-time testing and data transmission in order to place testing in the hands of patients. This will be accomplished through the use of the 2-D diffusion assay platform, which consists of a nanoscale """"""""nonfouling"""""""" poly(oligoethylene glycol methacrylate) brush coated glass chip that contains two types of printed microspots: """"""""stable"""""""" microspots of capture antibodies and """"""""soluble"""""""" microspots of detection reagents. A finger stick of blood is applied to the chip, and the protein analytes in the blood diffuse across the non-fouling brush and bind to stable spots of capture antibodies embedded within the brush. Simultaneously, the blood dissolves the soluble spots of fluorescently labeled detection antibodies, so that the detection antibodies can diffuse and label any analyte bound by the stable spots of capture antibodies. Detection is via a custom fluorescence detector that attaches to an Android smart phone and uses the phone's camera to record an image of the fluorescent microspots. Fluorescent spot intensities are converted to analyte concentration by a built in phone app. Images are automatically uploaded to a secure central server that allows a second analysis of the image to take place before automatically updating the patient's electronic health record. The assay incorporates a built in calibration scheme capable of minimizing many of the sampling variables inherent in POC testing. In addition, the microarray can be viewed through the custom detector by the naked eye and visually compared side-by-side with calibration spots when a smartphone is not available.

Public Health Relevance

The proposed research will develop a new point-of-care clinical test -the 2-D diffusion assay- for quantifying serum biomarker levels. In this assay, adding a drop of blood to the surface of a nanoscale polymer film allows a marker that is present in the patient's blood to bind to stable spots of capture antibodies. Simultaneously, the blood dissolves optically labeled detection antibodies that are printed as soluble spots, so that the detection antibodies can diffuse to the marker bound to stable spots of capture antibodies and complete the assay. A custom detector provides the ability to image spots with a smartphone camera and/or view the spots with the naked eye.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Small Business Technology Transfer (STTR) Grants - Phase I (R41)
Project #
1R41HL123871-01
Application #
8758457
Study Section
Special Emphasis Panel (ZHL1-CSR-S (M2))
Program Officer
Desvigne-Nickens, Patrice
Project Start
2014-09-19
Project End
2015-06-30
Budget Start
2014-09-19
Budget End
2015-06-30
Support Year
1
Fiscal Year
2014
Total Cost
$177,631
Indirect Cost
Name
Sentilus
Department
Type
DUNS #
078423830
City
Durham
State
NC
Country
United States
Zip Code
27705
Joh, Daniel Y; Hucknall, Angus M; Wei, Qingshan et al. (2017) Inkjet-printed point-of-care immunoassay on a nanoscale polymer brush enables subpicomolar detection of analytes in blood. Proc Natl Acad Sci U S A 114:E7054-E7062