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Ahmed MAM, Jurczak KM, Lynn NS, Mulder JPSH, Verpoorte EMJ, Nagelkerke A. Rapid prototyping of PMMA-based microfluidic spheroid-on-a-chip models using micromilling and vapour-assisted thermal bonding. Sci Rep 2024; 14:2831. [PMID: 38310102 PMCID: PMC10838337 DOI: 10.1038/s41598-024-53266-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 01/30/2024] [Indexed: 02/05/2024] Open
Abstract
The application of microfluidic devices as next-generation cell and tissue culture systems has increased impressively in the last decades. With that, a plethora of materials as well as fabrication methods for these devices have emerged. Here, we describe the rapid prototyping of microfluidic devices, using micromilling and vapour-assisted thermal bonding of polymethyl methacrylate (PMMA), to create a spheroid-on-a-chip culture system. Surface roughness of the micromilled structures was assessed using scanning electron microscopy (SEM) and atomic force microscopy (AFM), showing that the fabrication procedure can impact the surface quality of micromilled substrates with milling tracks that can be readily observed in micromilled channels. A roughness of approximately 153 nm was created. Chloroform vapour-assisted bonding was used for simultaneous surface smoothing and bonding. A 30-s treatment with chloroform-vapour was able to reduce the surface roughness and smooth it to approximately 39 nm roughness. Subsequent bonding of multilayer PMMA-based microfluidic chips created a durable assembly, as shown by tensile testing. MDA-MB-231 breast cancer cells were cultured as multicellular tumour spheroids in the device and their characteristics evaluated using immunofluorescence staining. Spheroids could be successfully maintained for at least three weeks. They consisted of a characteristic hypoxic core, along with expression of the quiescence marker, p27kip1. This core was surrounded by a ring of Ki67-positive, proliferative cells. Overall, the method described represents a versatile approach to generate microfluidic devices compatible with biological applications.
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Affiliation(s)
- Monieb A M Ahmed
- Pharmaceutical Analysis, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Klaudia M Jurczak
- W.J. Kolff Institute for Biomedical Engineering and Materials Science, University Medical Center Groningen, Groningen, The Netherlands
- Department of Surgery, University Medical Center Groningen, Groningen, The Netherlands
| | - N Scott Lynn
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - Jean-Paul S H Mulder
- Pharmaceutical Analysis, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Elisabeth M J Verpoorte
- Pharmaceutical Analysis, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Anika Nagelkerke
- Pharmaceutical Analysis, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands.
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Ueno R, Kuninori M, Sumi T, Sadeghian RB, Takata Y, Iguchi A, Tsuda M, Yamashita F, Ichikawa K, Yokokawa R. Relationship between Adsorption and Toxicity of Nephrotoxic Drugs in Microphysiological Systems (MPS). MICROMACHINES 2023; 14:761. [PMID: 37420994 DOI: 10.3390/mi14040761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/27/2023] [Accepted: 03/28/2023] [Indexed: 07/09/2023]
Abstract
Microphysiological systems (MPS) are an emerging technology for next-generation drug screening in non-clinical tests. Microphysiological systems are microfluidic devices that reconstitute the physiological functions of a human organ using a three-dimensional in vivo-mimicking microenvironment. In the future, MPSs are expected to reduce the number of animal experiments, improve prediction methods for drug efficacy in clinical settings, and reduce the costs of drug discovery. However, drug adsorption onto the polymers used in an MPS is a critical issue for assessment because it changes the concentration of the drug. Polydimethylsiloxane (PDMS), a basic material used for the fabrication of MPS, strongly adsorbs hydrophobic drugs. As a substitute for PDMS, cyclo-olefin polymer (COP) has emerged as an attractive material for low-adsorption MPS. However, it has difficulty bonding with different materials and, therefore, is not commonly used. In this study, we assessed the drug adsorption properties of each material constituting an MPS and subsequent changes in drug toxicity for the development of a low-adsorption MPSs using COP. The hydrophobic drug cyclosporine A showed an affinity for PDMS and induced lower cytotoxicity in PDMS-MPS but not in COP-MPS, whereas adhesive tapes used for bonding adsorbed a significant quantity of drugs, lowering their availability, and was cytotoxic. Therefore, easily-adsorbed hydrophobic drugs and bonding materials having lower cytotoxicity should be used with a low-adsorption polymer such as COP.
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Affiliation(s)
- Ryohei Ueno
- Department of Micro Engineering, Kyoto University, Kyoto 615-8540, Japan
- Toyo Seikan Group Holdings, Ltd., Yokohama 240-0062, Japan
| | | | - Takumi Sumi
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | | | - Yuji Takata
- Department of Micro Engineering, Kyoto University, Kyoto 615-8540, Japan
| | - Azusa Iguchi
- Toyo Seikan Group Holdings, Ltd., Yokohama 240-0062, Japan
| | - Masahiro Tsuda
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Fumiyoshi Yamashita
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | | | - Ryuji Yokokawa
- Department of Micro Engineering, Kyoto University, Kyoto 615-8540, Japan
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Trinh KTL, Thai DA, Lee NY. Bonding Strategies for Thermoplastics Applicable for Bioanalysis and Diagnostics. MICROMACHINES 2022; 13:1503. [PMID: 36144126 PMCID: PMC9501821 DOI: 10.3390/mi13091503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/05/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
Microfluidics is a multidisciplinary science that includes physics, chemistry, engineering, and biotechnology. Such microscale systems are receiving growing interest in applications such as analysis, diagnostics, and biomedical research. Thermoplastic polymers have emerged as one of the most attractive materials for microfluidic device fabrication owing to advantages such as being optically transparent, biocompatible, cost-effective, and mass producible. However, thermoplastic bonding is a key challenge for sealing microfluidic devices. Given the wide range of bonding methods, the appropriate bonding approach should be carefully selected depending on the thermoplastic material and functional requirements. In this review, we aim to provide a comprehensive overview of thermoplastic fabricating and bonding approaches, presenting their advantages and disadvantages, to assist in finding suitable microfluidic device bonding methods. In addition, we highlight current applications of thermoplastic microfluidics to analyses and diagnostics and introduce future perspectives on thermoplastic bonding strategies.
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Affiliation(s)
- Kieu The Loan Trinh
- Department of Industrial Environmental Engineering, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam-si 13120, Korea
| | - Duc Anh Thai
- Department of BioNano Technology, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam-si 13120, Korea
| | - Nae Yoon Lee
- Department of BioNano Technology, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam-si 13120, Korea
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Hammami S, Oseev A, Bargiel S, Zeggari R, Elie-Caille C, Leblois T. Microfluidics for High Pressure: Integration on GaAs Acoustic Biosensors with a Leakage-Free PDMS Based on Bonding Technology. MICROMACHINES 2022; 13:mi13050755. [PMID: 35630222 PMCID: PMC9145980 DOI: 10.3390/mi13050755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/07/2022] [Accepted: 05/09/2022] [Indexed: 02/04/2023]
Abstract
Microfluidics integration of acoustic biosensors is an actively developing field. Despite significant progress in “passive” microfluidic technology, integration with microacoustic devices is still in its research state. The major challenge is bonding polymers with monocrystalline piezoelectrics to seal microfluidic biosensors. In this contribution, we specifically address the challenge of microfluidics integration on gallium arsenide (GaAs) acoustic biosensors. We have developed a robust plasma-assisted bonding technology, allowing strong connections between PDMS microfluidic chip and GaAs/SiO2 at low temperatures (70 °C). Mechanical and fluidic performances of fabricated device were studied. The bonding surfaces were characterized by water contact angle measurement and ATR-FTIR, AFM, and SEM analysis. The bonding strength was characterized using a tensile machine and pressure/leakage tests. The study showed that the sealed chips were able to achieve a limit of high bonding strength of 2.01 MPa. The adhesion of PDMS to GaAs was significantly improved by use of SiO2 intermediate layer, permitting the bonded chip to withstand at least 8.5 bar of burst pressure. The developed bonding approach can be a valuable solution for microfluidics integration in several types of MEMS devices.
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Affiliation(s)
- Saber Hammami
- FEMTO-ST Institute, CNRS UMR-6174, Université de Bourgogne Franche-Comté, 25030 Besançon, France; (A.O.); (S.B.); (C.E.-C.)
- Correspondence: (S.H.); (T.L.)
| | - Aleksandr Oseev
- FEMTO-ST Institute, CNRS UMR-6174, Université de Bourgogne Franche-Comté, 25030 Besançon, France; (A.O.); (S.B.); (C.E.-C.)
| | - Sylwester Bargiel
- FEMTO-ST Institute, CNRS UMR-6174, Université de Bourgogne Franche-Comté, 25030 Besançon, France; (A.O.); (S.B.); (C.E.-C.)
| | - Rabah Zeggari
- FEMTO-Engineering, 15B Avenue des Montboucons, 25030 Besançon, France;
| | - Céline Elie-Caille
- FEMTO-ST Institute, CNRS UMR-6174, Université de Bourgogne Franche-Comté, 25030 Besançon, France; (A.O.); (S.B.); (C.E.-C.)
| | - Thérèse Leblois
- FEMTO-ST Institute, CNRS UMR-6174, Université de Bourgogne Franche-Comté, 25030 Besançon, France; (A.O.); (S.B.); (C.E.-C.)
- Correspondence: (S.H.); (T.L.)
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Recent Advances in Thermoplastic Microfluidic Bonding. MICROMACHINES 2022; 13:mi13030486. [PMID: 35334777 PMCID: PMC8949906 DOI: 10.3390/mi13030486] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 01/27/2023]
Abstract
Microfluidics is a multidisciplinary technology with applications in various fields, such as biomedical, energy, chemicals and environment. Thermoplastic is one of the most prominent materials for polymer microfluidics. Properties such as good mechanical rigidity, organic solvent resistivity, acid/base resistivity, and low water absorbance make thermoplastics suitable for various microfluidic applications. However, bonding of thermoplastics has always been challenging because of a wide range of bonding methods and requirements. This review paper summarizes the current bonding processes being practiced for the fabrication of thermoplastic microfluidic devices, and provides a comparison between the different bonding strategies to assist researchers in finding appropriate bonding methods for microfluidic device assembly.
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Zhang Q, Peng B, Chu M, Wen P, Wang S, Xu J. Curved Film Microstructure Arrays Fabricated via Mechanical Stretching. MICROMACHINES 2021; 12:1281. [PMID: 34832694 PMCID: PMC8617774 DOI: 10.3390/mi12111281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 10/10/2021] [Accepted: 10/16/2021] [Indexed: 12/21/2022]
Abstract
We report on curved film microstructure arrays fabricated through polydimethylsiloxane (PDMS) film buckling induced by mechanical stretching. In the process of the microstructure preparation, a PDMA film is glued on a bidirectionally prestretched PDMS sheet that has a square distributed hole array on its surface. After releasing the prestrain, the film microstructure array is created spontaneously. The fabricated microstructures possess a spherical surface and demonstrate very good uniformity. The film microstructure arrays can serve as microlens arrays with a focal length of 1010 μm. The microstructure formation mechanism is investigated via theoretical analysis and numerical simulation. The simulation results agree well with the experimental results. The prestrain applied by mechanical stretching during the fabrication has an important effect on the shape of the resulting film microstructures. The microstructure geometry can be easily tuned through controlling the applied prestrain.
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Affiliation(s)
| | - Bei Peng
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China; (Q.Z.); (M.C.); (P.W.); (S.W.); (J.X.)
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