Nanotechnology for point of care diagnostics Shana O. Kelley University of Toronto
Nanotechnology what is it and why is it relevant to medicine? Existing molecular diagnostic technologies strengths and weaknesses Development of a nanotechnology-enabledenabled platform for biomarker detection Application of platform in infectious disease
Working at the nanoscale Head of a pin: 1,000,000 nm Human hair: 60,000 nm DNA: 2 nm
Nanotechnology for biology and medicine Semiconductor quantum dots (2-20 nm) Medical imaging Nanowires (2-20 nm x 100-1000 nm) Biosensing Metallic nanoparticles (2-20 nm) Biosensing Therapeutics Carbon nanotubes (2-20 nm x 100-1000 nm) Biosensing Drug delivery Polymer nanoparticles (10-200 nm) Drug delivery
Nanotechnology for biology and medicine nanomaterials Biomolecules/disease biomarkers Biomolecules are nanoscale Nanomaterials have dimensions on right size scale for sensitive detection of their presence From Weiss et al, Science (2005) 307, 539.
Development of new nanobiosensors and bioelectronics Kelley research group: University of Toronto Detection of DNA, RNA, protein analytes Identification of diseased cells
Diagnostics used for infectious disease diagnosis PCR Faster, but expensive Culture cheap & accurate but slow heat cool X 40 10-9 M Becton Dickinson/Cepheid Leaders in MDx for infectious disease
Chip-based diagnostics for infectious disease diagnosis The goal: create a highly accurate, highly sensitive chip-based platform for inexpensive testing Low-cost Highly sensitive Multiplexed Standardized Small footprint/handheld Low power requirements Automated sample processing
SK1 Electronic/electrochemical sensors Glucose + glucose oxidase electrical current Compactness and simplicity of electrochemical sensors = low cost Free sensing units distributed to patient, pay for consumables
Slide 9 SK1 My resaerch group at U. Toronto Shana Kelley, 27/10/2008
Electronic/electrochemical DNA & RNA sensors reporter group target DNA/RNA sequence Immobilized probe sequence e - Electrical and electrochemical readout
Design of a nanomaterialsnanomaterials-based platform for biomolecular detection 500 nm opening in SiO2 Gold lead (5 µ) electroless deposition Collaboration with Prof. Ted Sargent, U. Toronto (ECE) electrodeposition Nanostructured microelectrode (NME)
Nanoscale sensing elements Feature size 100 nm 4 µm Feature size 5000 nm Feature size 20 nm L. Soleymani, Z. Fang, E.H. Sargent, S.O. Kelley, Nature Nanotechnology, 2009, in press, DOI: 10.1038/nnano.2009.276.
Nanoscale sensing elements
Nanoscale sensing elements + RNA - RNA As few as 100 molecules detected on-chip Proof-of-principle applications Prostate cancer biomarker analysis (Fang et al, ACS Nano, 2009) Micro RNA expression profiling (Yang et al, Angew. Chem., 2009)
Sensitivity controlled by nanostructuring of sensing elements 1 um 2 um 200 nm Limit of detection: 100,000,000 molecules Limit of detection: 1,000,000 molecules Limit of detection: 100 molecules L. Soleymani, Z. Fang, E.H. Sargent, S.O. Kelley, Nature Nanotechnology, 2009, in press, DOI: 10.1038/nnano.2009.276.
Next steps: instrument development USB/battery-powered chip reader software interface microfluidic sample handling
Design of specific probes for TB detection Several mycobacteriumspecific regions have been identified M: intra-species variable region M (166-219) A-E: primarily inter-species variable regions A (220-238) B (590-609) C (614-633) D (989-1008) E (1027-1046) EarI SmlI XhoI MslI PmlI NsiI Ppu10I Eco47III HaeII NaeI NgoMIV BtsI SspI Ecl136II PshAI SnaBI AccIII BsiHKAI SacI BsiEI Eco52I ScaI PstI SfcI ApoI EcoRI BsmI FspI EcoRV SgrAI AgeI AlwNI BbvCI BseRI EcoO109I ApaI BamHI XhoII BseSI PspOMI M A BC D E EciI VspI MluI XbaI BspMI BstAPI HincII AatII AhdI TfiI XmnI SmaI XmaI BsrGI BtrI BspHI Tth111I Also: devr, IS6110
Detection of antibiotic-resistant bacteria
Summary: Chip-based diagnostics for infectious disease A microchip platform with very high sensitivity has been developed low cost of fabrication makes technology suitable for patient screening A handheld chip reader is under development for testing in resource-limited settings A fully automated, rapid screening test for TB testing is one of the applications under development
Acknowledgments Kelley group Chip-based diagnostics Zhichao Fang Leyla Soleymani Van Tram Lisa Vasilveya Hooman Zamani Dr. Hong Yang Dr. George Pampalakis Dr. Heather Lord Collaborators Dr. Jeremy Squire (Queen s) Dr. Ted Sargent (U of T) Dr. Fei-Fei Liu (PMH) Financial Support OICR CIHR NSERC Prostate Cancer Foundation of Canada Genome Canada Ontario Centres of Excellence