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Separable bilayer microfiltration device for viable label-free enrichment of circulating tumour cells.

Zhou MD, Hao S, Williams AJ, Harouaka RA, Schrand B, Rawal S, Ao Z, Brenneman R, Gilboa E, Lu B, Wang S, Zhu J, Datar R, Cote R, Tai YC, Zheng SY - Sci Rep (2014)

Bottom Line: Addressing this challenge, we present a separable bilayer (SB) microfilter for viable size-based CTC capture.Unlike other single-layer CTC microfilters, the precise gap between the two layers and the architecture of pore alignment result in drastic reduction in mechanical stress on CTCs, capturing them viably.In a metastatic mouse model, SB microfilters successfully enriched viable mouse CTCs from 0.4-0.6 mL whole mouse blood samples and established in vitro cultures for further genetic and functional analysis.

View Article: PubMed Central - PubMed

Affiliation: Micro &Nano Integrated Biosystem (MINIBio) Laboratory, Department of Biomedical Engineering and Materials Research Institute, Pennsylvania State University, University Park, PA 16802, U.S.A.

ABSTRACT
The analysis of circulating tumour cells (CTCs) in cancer patients could provide important information for therapeutic management. Enrichment of viable CTCs could permit performance of functional analyses on CTCs to broaden understanding of metastatic disease. However, this has not been widely accomplished. Addressing this challenge, we present a separable bilayer (SB) microfilter for viable size-based CTC capture. Unlike other single-layer CTC microfilters, the precise gap between the two layers and the architecture of pore alignment result in drastic reduction in mechanical stress on CTCs, capturing them viably. Using multiple cancer cell lines spiked in healthy donor blood, the SB microfilter demonstrated high capture efficiency (78-83%), high retention of cell viability (71-74%), high tumour cell enrichment against leukocytes (1.7-2 × 10(3)), and widespread ability to establish cultures post-capture (100% of cell lines tested). In a metastatic mouse model, SB microfilters successfully enriched viable mouse CTCs from 0.4-0.6 mL whole mouse blood samples and established in vitro cultures for further genetic and functional analysis. Our preliminary studies reflect the efficacy of the SB microfilter device to efficiently and reliably enrich viable CTCs in animal model studies, constituting an exciting technology for new insights in cancer research.

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Related in: MedlinePlus

Process flow of SB microfilter device fabrication.(a) Deposition and patterning of bottom layer parylene-C; (b) Patterning of sacrificial photoresist; (c) Deposition and patterning of top layer parylene-C; (d) Removal of residual aluminum film and sacrificial photoresist; (e) Release of device from the substrate.
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f7: Process flow of SB microfilter device fabrication.(a) Deposition and patterning of bottom layer parylene-C; (b) Patterning of sacrificial photoresist; (c) Deposition and patterning of top layer parylene-C; (d) Removal of residual aluminum film and sacrificial photoresist; (e) Release of device from the substrate.

Mentions: Figure 7 illustrates the process flow of the device fabrication. It began with surface treatment of a single side 6-inch wafer with oxygen plasma. The first layer of 10 μm-thick parylene-C was deposited subsequently. A thin layer of aluminum was thermally evaporated and patterned with lithography and aluminum etchant type D. Parylene-C was etched with oxygen plasma with the aluminum as the mask. A 5.5 μm-thick SPR 955 photoresist was spin-coated after dissolving the aluminum mask with aluminum etchant. The photoresist was patterned with photolithography and serves as the sacrificial layer, which defined the gap between the top and the bottom parylene-C layers. A second layer of 10 μm-thick parylene-C was deposited. Prior to the deposition for the second layer of parylene-C, the exposed area of the first layer parylene-C was treated with oxygen plasma. Another layer of aluminum was thermally deposited and patterned with photolithography and aluminum etchant. The top parylene-C was patterned with oxygen plasma, after which the aluminum mask was dissolved again with aluminum etchant. The sacrificial photoresist was dissolved with acetone and rinsed with isopropyl alcohol and deionized water. Finally the device was released from the substrate.


Separable bilayer microfiltration device for viable label-free enrichment of circulating tumour cells.

Zhou MD, Hao S, Williams AJ, Harouaka RA, Schrand B, Rawal S, Ao Z, Brenneman R, Gilboa E, Lu B, Wang S, Zhu J, Datar R, Cote R, Tai YC, Zheng SY - Sci Rep (2014)

Process flow of SB microfilter device fabrication.(a) Deposition and patterning of bottom layer parylene-C; (b) Patterning of sacrificial photoresist; (c) Deposition and patterning of top layer parylene-C; (d) Removal of residual aluminum film and sacrificial photoresist; (e) Release of device from the substrate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4260227&req=5

f7: Process flow of SB microfilter device fabrication.(a) Deposition and patterning of bottom layer parylene-C; (b) Patterning of sacrificial photoresist; (c) Deposition and patterning of top layer parylene-C; (d) Removal of residual aluminum film and sacrificial photoresist; (e) Release of device from the substrate.
Mentions: Figure 7 illustrates the process flow of the device fabrication. It began with surface treatment of a single side 6-inch wafer with oxygen plasma. The first layer of 10 μm-thick parylene-C was deposited subsequently. A thin layer of aluminum was thermally evaporated and patterned with lithography and aluminum etchant type D. Parylene-C was etched with oxygen plasma with the aluminum as the mask. A 5.5 μm-thick SPR 955 photoresist was spin-coated after dissolving the aluminum mask with aluminum etchant. The photoresist was patterned with photolithography and serves as the sacrificial layer, which defined the gap between the top and the bottom parylene-C layers. A second layer of 10 μm-thick parylene-C was deposited. Prior to the deposition for the second layer of parylene-C, the exposed area of the first layer parylene-C was treated with oxygen plasma. Another layer of aluminum was thermally deposited and patterned with photolithography and aluminum etchant. The top parylene-C was patterned with oxygen plasma, after which the aluminum mask was dissolved again with aluminum etchant. The sacrificial photoresist was dissolved with acetone and rinsed with isopropyl alcohol and deionized water. Finally the device was released from the substrate.

Bottom Line: Addressing this challenge, we present a separable bilayer (SB) microfilter for viable size-based CTC capture.Unlike other single-layer CTC microfilters, the precise gap between the two layers and the architecture of pore alignment result in drastic reduction in mechanical stress on CTCs, capturing them viably.In a metastatic mouse model, SB microfilters successfully enriched viable mouse CTCs from 0.4-0.6 mL whole mouse blood samples and established in vitro cultures for further genetic and functional analysis.

View Article: PubMed Central - PubMed

Affiliation: Micro &Nano Integrated Biosystem (MINIBio) Laboratory, Department of Biomedical Engineering and Materials Research Institute, Pennsylvania State University, University Park, PA 16802, U.S.A.

ABSTRACT
The analysis of circulating tumour cells (CTCs) in cancer patients could provide important information for therapeutic management. Enrichment of viable CTCs could permit performance of functional analyses on CTCs to broaden understanding of metastatic disease. However, this has not been widely accomplished. Addressing this challenge, we present a separable bilayer (SB) microfilter for viable size-based CTC capture. Unlike other single-layer CTC microfilters, the precise gap between the two layers and the architecture of pore alignment result in drastic reduction in mechanical stress on CTCs, capturing them viably. Using multiple cancer cell lines spiked in healthy donor blood, the SB microfilter demonstrated high capture efficiency (78-83%), high retention of cell viability (71-74%), high tumour cell enrichment against leukocytes (1.7-2 × 10(3)), and widespread ability to establish cultures post-capture (100% of cell lines tested). In a metastatic mouse model, SB microfilters successfully enriched viable mouse CTCs from 0.4-0.6 mL whole mouse blood samples and established in vitro cultures for further genetic and functional analysis. Our preliminary studies reflect the efficacy of the SB microfilter device to efficiently and reliably enrich viable CTCs in animal model studies, constituting an exciting technology for new insights in cancer research.

Show MeSH
Related in: MedlinePlus