A HIGH-PERFORMANCE MICROSYSTEM FOR ISOLATING VIABLE CIRCULATING TUMOR CELLS Xiangjun Zheng1, Siu-Lun Cheung1, Joyce A Schroeder2,3, Linan Jiang1,4, and Yitshak Zohar1,3,5 1Dept.

Aerospace and Mechanical Engineering, 2Dept. Molecular and Cellular Biology, Cancer Center, 4College of Optical Sciences, 5Dept. Biomedical Engineering,

3Arizona

The University of Arizona, Tucson, Arizona, USA

Methodology -

Attachment Set-ups Buffer Inlet

Inlet

Outlet

Flow L1

1 cm

R1

1 cm

L1

R2

Cell Capture Attachment Rate αA

R1

MDA-MB-231

+

++

BT-20

+++

-

R2

MDA-MB-231:BT-20 = 1:1000 (in anti-cadherin-11 M/Cs) • cell suspension 100μ m

0.6 0.4

0.0 1 1.5 2 2.5 3 Flow Rate Q [μl/min]

3.5

Attachment Rate αA

• in anti-cadherin-11 M/Cs 1.0

• captured cells

MDA-MB-231 BT-20

0.8

Sensitivity & Specificity

0.5

100μ m

0.6 0.4 0.2 0.0 0

0.5

1 1.5 2 2.5 3 Flow Rate Q [μl/min]

0.6 0.4 MDA-MB-231 BT-20

0.2

0.0

0.4 0.8 1.2 1.6 2.0 Steady-state Flow Rate Q [ml/min]

1.0

SN SP

0.8 0.6 0.4

Sensitivity Specificity

0.2 0.0

-4

100μ m

0.8

Retained cells after detachment

0.6 0.4 MDA-MB-231 BT-20

0.2

0.0

-3

-2

10 10 0.1 11 10 0.001 0.01 0.1 10 MDA-MB-231:BT-20 Cell Concentration Ratio

1.0

0.0

0.0

TN TN + FP

MDA-MB-231:BT-20 = 1:1000 (in anti-cadherin-11 M/Cs)

• in anti-adherin-11 M/Cs Detachment Rate αD

Detachment Rate αD

0.8

Specificity: S P =

Detachment of Bound Cells

(Homogenous Suspensions) 1.0

TP TP + FN

10 0.0001

3.5

Detachment of Bound Cells • in anti-EpCAM M/Cs

Sensitivity: S N =

TP : # captured target cells FN : # escaped target cells TN : # disposed non-target cells FP : # bound non-target cells

0.2

0

EpCAM cadherin-11

Target Cell Capture from Mixtures

MDA-MB-231 BT-20

0.8

Blocked

Flow

(Homogeneous Suspensions) • in anti-EpCAM M/Cs 1.0

Cell lines and receptors Receptor expression

0.4 0.8 1.2 1.6 2.0 Steady-state Flow Rate Q [ml/min]

Sensitivity & Specificity

Cell Sample Inlet

Outlet

Detachment Set-ups

1.0

Sensitivity

Specificity

0.9 0.8 0.7 0.6 0.5

1

Before Detachment

2 After Detachment

CONCLUSIONS ¾ Circulating tumor cells, MDA-MB-231 and BT-20, are captured in microchannels functionalized with specific antibodies, either anti-EpCAM or anti-cadherin-11. ¾ Target cells are captured from binary mixtures with sensitivity close to 100% and specificity of about 85%. ¾ A two-step flow control combining attachment and detachment steps improves the capture specificity of target cells to about 95% with close to 100% sensitivity.

1