(a) Schematic of the tube preparation: (i) activation of PDMS tube surface; (ii) amine functionalized tube surface; (iii) antibody conjugation.

<p>(b) Photomicrograph of the tube, were functionalized with human anti-EpCAM (Scale bar in mm). (c & d) PC-3 cells were placed in an unmodified tube (without EpCAM coating), as control experiments, demonstrating absence of any captured cells in the cavity of the tube. (d) (e) Fluorescence microscopic images of captured PC-3 cells on anti-EpCAM immobilized tube and (f) phase contrast image of the same PC-3 cells.</p

Schematic of the proposed device in operation.

<p>Photosensitizer-antibody conjugate is injected prior to PDT procedure. Blood circulation was guided by medical tubing with a peristaltic pump. Extracorporeal PDT is performed as the blood flows through the tube inside a reflective chamber. The treated blood is returned to body. All procedures are accomplished in a constant flow mode.</p

The quantitative analysis of PDT outcome for PC-3 cells in tube.

<p>(mean ± SEM) <i>**P<0</i>.<i>001 PDT treated vs</i>. <i>no conjugate control and no light control using t-test</i>. <i>N = 3</i>.</p

Cell count estimation by flow cytometry.

<p>The values are of mean ± standard error of the mean (n = 3). <i>P<</i> 0.01 of control vs. immobilized tube <i>t-test</i>.</p

Results of photodynamic therapy in a tube after2 min illumination.

<p>The tube’s diameter is 1.02 mm, which is within the range of penetration depth of light given that the tube is illuminated from all directions, for this reason there is accelerated cell death compared to the results in media, as shown in the left hand side “PDT in blood” column.</p

Quantitative analysis of cell capture from hemocytometry.

<p>Three independent experiments exhibited an average of 44.7% capture efficiency in PC-3 cell spiked whole blood system. <i>P<</i> 0.01 <i>initial vs</i>. <i>final</i>, <i>t-test</i>.</p

Cell count estimation by hemocytometry.

<p>The values are of mean ± standard error of the mean (n = 3). P<0.001 of control vs. immobilized tube <i>t-test</i>.</p

(a) Fluorescence microscopy images for captured PC-3 cells on anti-EpCAM immoibized tubes in the presence of whole blood.

<p>The PC-3 cells were pre-stained by Calcein AM and Na-citrate was used as an anticoagulant for the blood sample. (b) and (c) are representative images PC-3 cells from the hemocytometry counting using Calcein AM fluorescence. Initial (b) showed significantly more cells than final (c), indicating reduction of cell density by capture.</p

Results of photodynamic therapy after 2 minutes illumination on a TC plate of PC-3 cells.

<p>The cells were stained with Calcein AM. The left hand column “PDT in blood” demonstrates diminished cell death with increasing light exposure as compared to the right hand “no blood” column due to light absorption effects by components present in blood. The negative controls do not exhibit any cell death.</p

Representative flow cytometry dot plots.

<p>The figures in the two upper panel rows clearly demonstrated the reduction in cell count by anti-EpCAM immobilized tubes, while the figures in the two lower panel rows showed minor difference between initial and final count by unmodified tube used as a control.</p