3D thermoplastic elastomer microfluidic devices for biological probe immobilization

Brassard, D.; Clime, Liviu; Li, Kebin; Geißler, Matthias; Miville-Godin, Caroline; Roy, Emmanuel; Veres, Teodor

doi:10.1039/c1lc20714h

Cited by 40 publications

(33 citation statements)

References 61 publications

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“…In principle, open through-hole membranes can be produced from other elastomers such as poly(dimethylsiloxane) (PDMS), which to this end constitutes the prime material for soft microfabrication and patterning (35,36). However, the method described herein provides several advantages with respect to fabrication and handling of the membranes (37). For example, Versaflex CL30 provides off-the-shelf availability as it can be stored (e.g., as an extruded sheet) over extended periods of time, whereas PDMS as a thermoset polymer necessitates timely preparation.…”

Section: Resultsmentioning

confidence: 99%

“…Due to their tendency to grow in colonies, HeLa-R cells are preferably seeded on a Zeonor substrate from which the membrane was removed upon oxygen plasma treatment. Regardless of the option used, formation of OPS benefits from the ability of the elastomeric membrane to achieve intimate, yet reversible contact with the substrate (37). OPS ranging from 200 to 400 μm in diameter enable cell growth in defined, well-populated islands, whereas 50-μm OPS (either circular or rectangular) result in groups with a limited number (e.g., 2-9 cells) for both HeLa and HeLa-R cell lines.…”

Section: Resultsmentioning

confidence: 99%

“…We use an open through-hole membrane fabricated from an elastomeric blockcopolymer (e.g., Versaflex CL30, GLS Corp.) (37) (see SI Text for details) in combination with oxygen plasma treatment to achieve live cell patterns on an insulating plastic substrate (e.g., Zeonor 1060R, Zeon Chemicals). Versaflex CL30 is a meltprocessable styrenic ethylene/butylene block-copolymer (38,39) which has recently been shown to promote the fabrication of thin-film membranes with small-scale openings in a single step using hot embossing lithography (HEL) (37). In principle, open through-hole membranes can be produced from other elastomers such as poly(dimethylsiloxane) (PDMS), which to this end constitutes the prime material for soft microfabrication and patterning (35,36).…”

Section: Resultsmentioning

confidence: 99%

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Assessment of multidrug resistance on cell coculture patterns using scanning electrochemical microscopy

Kuss

Polcari

Geißler

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

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The emergence of resistance to multiple unrelated chemotherapeutic drugs impedes the treatment of several cancers. Although the involvement of ATP-binding cassette transporters has long been known, there is no in situ method capable of tracking this transporter-related resistance at the single-cell level without interfering with the cell's environment or metabolism. Here, we demonstrate that scanning electrochemical microscopy (SECM) can quantitatively and noninvasively track multidrug resistance-related protein 1-dependent multidrug resistance in patterned adenocarcinoma cervical cancer cells. Nonresistant human cancer cells and their multidrug resistant variants are arranged in a side-by-side format using a stencil-based patterning scheme, allowing for precise positioning of target cells underneath the SECM sensor. SECM measurements of the patterned cells, performed with ferrocenemethanol and [Ru(NH 3 ) 6 ] 3+ serving as electrochemical indicators, are used to establish a kinetic "map" of constant-height SECM scans, free of topography contributions. The concept underlying the work described herein may help evaluate the effectiveness of treatment administration strategies targeting reduced drug efflux.ancer cells, such as lung cancer or leukemia, acquire resistance to multiple unrelated drugs in response to treatment with chemotherapeutic agents (1, 2). Resistance impedes therapeutic effectiveness, which in turn, reduces the long-term survival rate of cancer patients (2). The emergence of multidrug resistance (MDR) involves the overexpression of transmembrane proteins P-glycoprotein (P-gp) and MDR-related protein 1 (MRP1), which both belong to the family of 5′-triphosphatebinding cassette transporters (known as ABC transporters). P-gp and MRP1 act as molecular "pumps," actively removing therapeutic agents from the cancer cells, thereby preventing the drug from inducing the desired effect on the cell nucleus or cytoplasm. MDR based on P-gp is relatively well understood and involves binding of hyaluronan to the cell surface glycoprotein CD44. The resulting up-regulation of the transcriptional cofactor p300 expression and therefore the NFkappaB-specific transcriptional up-regulation lead to the production of P-gp, and with that chemoresistance in cells (3). However, the mechanism that causes MRP1-mediated MDR remains unclear.Currently, quantification of MDR relies on immunohistochemical analyses, such as real-time PCR, focusing mostly on P-gp or other members of ABC transporters (4-9). Fluorescent MRP1-specific studies were also conducted, revealing that resistant and nonresistant cancer cells have differential intracellular content of glutathione and GST, which affect their cell death mechanism during hyperthermia (10). Microvoltammetry was also used to measure the efflux of chemotherapeutic drugs from normal and MDR cancer cells on the single-cell level, with detection limits in the nanomolar range (11). Finally, flow cytometry has routinely been used to quantify and compare expression levels and activity of dif...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Assessment of multidrug resistance on cell coculture patterns using scanning electrochemical microscopy

Kuss

Polcari

Geißler

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

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“…The novelty of the work relies on the simplified strategy to create region specific anchoring of oligonucleotides on a wide variety of substrates (silicon, glass, gold), respect to current procedures 7,[13][14][15][16][17] : for the first time a spin-on ZrO 2 photosensitive material that can be directly patterned and easily integrated in microfluidic platforms is converted to crystalline ZrO 2 interface with maximized affinity to oligonucleotides anchoring in a straightforward procedure.…”

Section: Introductionmentioning

confidence: 99%

Straightforward Micropatterning of Oligonucleotides in Microfluidics by Novel Spin-On ZrO₂ Surfaces

Giustina

Zambon

Lamberti

et al. 2015

ACS Appl. Mater. Interfaces

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DNA biochip assays often require immobilization of bioactive molecules on solid surfaces. A simple biofunctionalization protocol and precise spatial binding represent the two major challenges in order to obtain localized region specific biopatterns into lab-on-a-chip (LOC) systems. In this work, a simple strategy to anchor oligonucleotides on microstructured areas and integrate the biomolecules patterns within microfluidic channels is reported. A photosensitive ZrO2 system is proposed as an advanced platform and versatile interface for specific positioning and oriented immobilization of phosphorylated DNA. ZrO2 sol-gel structures were easily produced on fused silica by direct UV lithography, allowing a simple and fast patterning process with different geometries. A thermal treatment at 800 °C was performed to crystallize the structures and maximize the affinity of DNA to ZrO2. Fluorescent DNA strands were selectively immobilized on the crystalline patterns inside polydimethylsiloxane (PDMS) microchannels, allowing high specificity and rapid hybridization kinetics. Hybridization tests confirmed the correct probe anchoring and the bioactivity retention, while denaturation experiments demonstrated the possibility of regenerating the surface.

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“…13 Alternative elastomers for microfluidics include off-stoichiometric thiol-ene (OSTE) 14 and thermoplastic elastomers. 15 Compared with PDMS, these materials allow a wider range of property tailoring (e.g., stiffness and permeability) and potentially faster processing.…”

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confidence: 99%

A practical guide for the fabrication of microfluidic devices using glass and silicon

Iliescu¹,

Taylor²,

Avram³

et al. 2012

Biomicrofluidics

310

207

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This paper describes the main protocols that are used for fabricating microfluidic devices from glass and silicon. Methods for micropatterning glass and silicon are surveyed, and their limitations are discussed. Bonding methods that can be used for joining these materials are summarized and key process parameters are indicated. The paper also outlines techniques for forming electrical connections between microfluidic devices and external circuits. A framework is proposed for the synthesis of a complete glass/silicon device fabrication flow. I. WHY USE SILICON AND GLASS IN MICRO-AND NANO-FLUIDIC APPLICATIONS?Micro-and nano-fluidic technology continues to be embraced by biologists, 1-3 chemists, 4 and engineers throughout academia and industry. As its applications have expanded, there has been an explosion in the range of materials and processes used to fabricate these devices. The earliest microfluidic devices (e.g., gas 5 and liquid 6 chromatography devices) were made from silicon and glass and borrowed processes directly from semiconductor and microelectromechanical systems (MEMS) manufacturing. 7 Now, however, many researchers have moved away from silicon and glass, and instead use cast elastomers such as polydimethylsiloxane (PDMS)-which is ideal for swift prototyping-or thermoplastic polymers, which can be hot-embossed or injection-molded and are well suited to inexpensive manufacturing. Yet, there remain many applications where glass and silicon offer advantages over polymeric materials. In this paper, we highlight these advantages and offer a framework for selecting fabrication processes when using silicon and glass. A. The dominance of soft lithographyOver the last decade, PDMS has become virtually the default material for forming microfluidic devices, 8 because of the sheer ease with which it can be cast on to a micro-scale mould and then strongly bonded to glass. 9 The elastomeric nature of the material has been exploited to integrate fluidic valves and pumps on-chip and has simplified the production of multi-layer devices because the soft layers readily conform to each other. 10,11 Yet, the low stiffness (usually <1 MPa) of PDMS relative to amorphous thermoplastics, silicon, and glass has its own a) Authors to whom correspondence should be addressed. Electronic addresses: ciliescu@ibn.a-star.edu.sg and hkt@ntu.edu.sg. 6, 016505 (2012) drawbacks. High aspect-ratio channels are notoriously difficult to fabricate in PDMS because of their propensity to collapse. 12 Moreover, difficulties in automating the handling of such a soft material have hampered efforts to scale up PDMS device manufacturing. Meanwhile, PDMS's high oxygen and water permeabilities have proved both a blessing and a curse in different applications.The hydrophobic nature of PDMS can be an important consideration for some biological applications. In drug screening applications, for example, hydrophobic drugs as well as metabolites (urea or albumin) can be absorbed into the device's material due to hydrophobic--hydrophobic interaction...

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3D thermoplastic elastomer microfluidic devices for biological probe immobilization

Cited by 40 publications

References 61 publications

Assessment of multidrug resistance on cell coculture patterns using scanning electrochemical microscopy

Assessment of multidrug resistance on cell coculture patterns using scanning electrochemical microscopy

Straightforward Micropatterning of Oligonucleotides in Microfluidics by Novel Spin-On ZrO₂ Surfaces

A practical guide for the fabrication of microfluidic devices using glass and silicon

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3D thermoplastic elastomer microfluidic devices for biological probe immobilization

Cited by 40 publications

References 61 publications

Assessment of multidrug resistance on cell coculture patterns using scanning electrochemical microscopy

Assessment of multidrug resistance on cell coculture patterns using scanning electrochemical microscopy

Straightforward Micropatterning of Oligonucleotides in Microfluidics by Novel Spin-On ZrO2 Surfaces

A practical guide for the fabrication of microfluidic devices using glass and silicon

Contact Info

Product

Resources

About

Straightforward Micropatterning of Oligonucleotides in Microfluidics by Novel Spin-On ZrO₂ Surfaces