HANDHELD DIAGNOSTICS OF CANCER BIOMARKERS

IN EXHALED BREATH

PRESENTED BY: chinchu elezebeth

INTRODUCTION

Cancer refers to the proliferation of abnormal cells that grow beyond their normal boundaries, and invade adjacent tissues and spread to other organs.

The most common cancers are lung, breast, colon-rectum, stomach, prostrate and liver.

Cancer can be diagnosed by imaging, endoscopy, biopsy, radionuclide screening, ultrasonography etc.

BREATH ANALYSIS• Breath analysis was started after the discovery of

about 250 volatile organic compounds (VOC’s)in exhaled breath by Linus Pauling .

Exhaled breath is collection of potential biomarkers for various systemic and respiratory diseases.

Breath odour points to many illness – diabetes : acetone.

Exhaled breath- dead space and alveolar space.

Breath analysis has been recently utilized as a cancer screening tool.

Cancer is accompanied by increased oxidative stress, which in turn can be detected by increased excretion of volatile alkanes in breath.

Cancer biomarkers in breath includes pentane, benzene, heptane, toluene, octane, nonane, decane, undecane, dodacene, and tetradecane and also certain gases like nitric oxideand haem oxygenase.

The primary technique for the analysis of volatiles in breath is gas chromatography preceded with sample trapping/preconcentration.

ADVANTAGES OF BREATH ANALYSIS

Noninvasive and painless testing. Rapid results. Minimal biohazard waste. No special training. Continuous monitoring. Can be used on people of all ages

APPLICATIONS OF BREATH ANALYSIS Detection of alcohol in breath.

To detect conditions like cancer or tuberculosis. Hearts breath test to check organ rejection.

Clinical applications of breath biomarkers

Handheld cancer screening system

The VOC’s enter the device,collected by μPC.

VOC’s injected in a concentration pulse by thermal desorption into a micro column for chromatographic separation.

Detector.

HANDHELD BREATH ANALYZER-CURRENT STATE OF THE ART

Micro Gas Chromatography Systems

CAPTURE AND

INJECTIONSEPARATION

DETECTIONμPC

separation column- separation of chemical mixture. detector- single or array of detectors to resolve the eluted analytes. silicon micromachining technology.

PRECONCENTRATION

process of target analyte enrichment. increases analysis speed and detection performance. allows detection in concentration range of ppb and ppt. tube made of stainless steel or precision bore borosilicate

glass to hold the adsorbant. exhaustive and equilibrium μPC. exhaustive –microchannels packed with granular adsorbant. equilibrium-3D microstructures coated with sorbent

material. adsorbant used is TENAX-TA.

TENAX-TA

Tenax-TA is a porous polymer resin based on 2.6-diphenylene oxide.

Trap Volatiles from Air, Liquids and Solids. High Temperature Limit of 350 oc Low Affinity for Water. Tenax TA can be applied both as a column packing

material and for traps for organic volatile and semi-volatile compounds.

DESIGN

• 3D microstructures embedded within a micro cavity of silicon-glass bonded chip.

• AIM: increase the surface-to-volume ratio.• OD- 12mmx12mm

3D rendering of the silicon-glass μPC.

Square shaped pillars provide the largest surface area. Maltese cross design increases the area by 72%.

shape Footprint (mm2 ) Surface area (mm2 )

square 0.0025 0.070

Maltese-cross 0.0008 0.120

Pillar designs can of two types ordered and staggered. Staggered designs prevents stagnation regions.

SIMULATED FLOW VELOCITY PROFILE

Square Maltese cross

blue regions represents zero velocity

(a) Spinning of photoresist (PR9260), (b) Photolithography(c) Deep reactive-ion etching (DRIE) (d) Dispensing of adsorbentsolution droplets, (e) Anodic bonding.

FABRICATION

• Microstructures were coated with adsorbent material TENAX-TA.

• TENAX-TA in dichloromethane – conc: 10mg/ml.

• wafer dipped in TENAX-TA solution wafer dipped in methanol TENAX-TA precipitated from solution and deposited on the pillar surfaces.

SEM micrograph of precipitated Tenax-TA on the pillars

EXPERIMENTAL SETUP

• Performance of μPC’s are evaluated in terms of sample adsorption/ desorption.

• Carried out in commercial GC oven for isothermal condition.

• Sample adsorption/desorption and chromatographic seap measured by a flame ionization detector.

• High performance ceramic heater for thermal desorption.

• Thermocouple for manual temperature control and also a gas flow controller to supply nitrogen carrier gas.

• Testing setup consists of six -port zero-dead-volume valves and deactivated fused silica transfer lines.

TESTING SETUP

• (a)- sample injected into the GC injector.

The GC column kept offline. •(b)- GC column connected to PC.

μPC heated to 250 oc at 100 oc/s to inject sample into column.

pressure- 1 mL/min.•( c)- μPC offline.

Column heated to 150 oc from 35 oc at 30 oc/min.

valves set in the (a) loading position, (b) injection position, and (c) separation position.

NONANE PROBE

• Probe used for sample capacity determination- Nonane

• Nonane is a linear alkane hydrocarbon with the chemical formula C9H20.

• saturated at 40 oc • desorbed at 100 oc/s to 250 oc• REASON : low reactivity

RESULTS AND DISCUSSION

Nonane concentration for diff pillar design

Nonane conc. for ordered and staggered pillar arrangement

DILUTE SAMPLE PRECONCENTRATED SAMPLE

CONCLUSION

• Used for early cancer detection.• It is non invasive and painless .• MEMS technology- μPC development for

preconcentration of VOC’s to detectable levels.• Sensitive,acurate,reliable and easy to use screening

system at low cost.

BREATH ANALYZERS

REFERENCE Bassam Alfeeli and Mausoud Agah, Towards Handheld Diagnostics of Cancer Biomarkers in Breath: Micro Preconcentration of Trace Levels of Volatiles in Human Breath,IEEE Sensors Journal,Vol.11,No.11,November 2011,p.2756-2762.

Bassam Alfeeli and Mausoud Agah, Micro preconcentrator with Embedded 3D Pillars forBreath Analysis Applications,IEEE Sensors 2008 conference,p.736-739.

.

Paul S.Monks and Kerry A.Willis, Breath Analysis,Education in Chemistry,July 2010,p.110-118.

Bassam Alfeeli and Mausoud Agah, Micro Preconcentrator for Handheld Diagnostics of Cancer Biomarkers in Breath,IEEE Sensors 2010 Conference,p.2490-2493.

Michael Phillips, Renee N Cataneo, Christobel Saunders,Peter Hope, Peter Schmitt and JamesWai, Volatile biomarkers in the breath of women with breast cancer,Journal Of Breath Research,March 2010,p.1752-1759.

N M Grob, M Aytekin and R A Dweik, Biomarkers in exhaled breath condensate: a review of collection,processing and analysis, J Breath Res. September 2008,p.1-33

QUERIES

THANK YOU