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Wang G, Yang C, Shan M, Jia H, Zhang S, Chen X, Liu W, Liu X, Chen J, Wang X. Synergistic Poly(lactic acid) Antibacterial Surface Combining Superhydrophobicity for Antiadhesion and Chlorophyll for Photodynamic Therapy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:8987-8998. [PMID: 35839422 DOI: 10.1021/acs.langmuir.2c01377] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The problem of nosocomial infections caused by bacterial growth on material surfaces is an urgent threat to public health. Although numerous materials and methods have been explored to fight against infections, the methods are complicated and the materials are slightly toxic. It is highly desirable to develop an antibacterial strategy that kills bacteria effectively without drug resistance and cytotoxicity. Herein, we present a synergistic antibacterial polylactic acid (PLA) surface with superhydrophobic antibacterial adhesion and photodynamic bactericidal activity. Initially, the surface displayed low-adhesion superhydrophobicity and resisted most bacterial adhesion. Furthermore, completely non-toxic chlorophyll possessed excellent photodynamic bactericidal properties under non-toxic visible light, which was incorporated into micro-/nanoscale PLA surfaces. We achieved efficient antibacterial activity using completely non-toxic materials and a facile non-solvent-induced phase separation process. This non-toxic, simple, good biocompatible, and no drug-resistant strategy has great advantages in combating bacterial infections.
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Affiliation(s)
- Gege Wang
- School of Materials Science and Engineering, the Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China
| | - Cao Yang
- School of Materials Science and Engineering, the Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China
| | - Mengyao Shan
- School of Materials Science and Engineering, the Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China
| | - Hanyu Jia
- School of Materials Science and Engineering, the Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China
| | - Shike Zhang
- School of Materials Science and Engineering, the Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China
| | - Xin Chen
- College of Food Science and Engineering, National Engineering Laboratory for Wheat & Corn Further Processing, Henan University of Technology, Zhengzhou 450001, China
| | - Wentao Liu
- School of Materials Science and Engineering, the Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China
| | - Xuying Liu
- School of Materials Science and Engineering, the Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China
| | - Jinzhou Chen
- School of Materials Science and Engineering, the Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China
| | - Xianghong Wang
- School of Materials Science and Engineering, the Key Laboratory of Material Processing and Mold of Ministry of Education, Henan Key Laboratory of Advanced Nylon Materials and Application, Zhengzhou University, Zhengzhou 450001, China
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Babu S, Dousti B, Lee GS, Lee JB. Conversion of Polymer Surfaces into Nonwetting Substrates for Liquid Metal Applications. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:8139-8147. [PMID: 34180680 DOI: 10.1021/acs.langmuir.1c00689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Liquid metal-based applications are limited by the wetting nature of polymers toward surface-oxidized gallium-based liquid metals. This work demonstrates that a 120 s CF4/O2 plasma treatment of polymer surfaces-such as poly(dimethylsiloxane) (PDMS), SU8, S1813, and polyimide-converts these previously wetting surfaces to nonwetting surfaces for gallium-based liquid metals. Static and advancing contact angles of all plasma-treated surfaces are >150°, and receding contact angles are >140°, with contact angle hysteresis in the range of 8.2-10.7°, collectively indicating lyophobic behavior. This lyophobic behavior is attributed to the plasma simultaneously fluorinating the surface while creating sub-micron scale roughness. X-ray photoelectron spectroscopy (XPS) results show a large presence of fluorine at the surface, indicating fluorination of surface methyl groups, while atomic force microscopy (AFM) results show that plasma-treated surfaces have an order of magnitude greater surface roughness than pristine surfaces, indicating a Cassie-Baxter state, which suggests that surface roughness is the primary cause of the nonwetting property, with surface chemistry making a smaller contribution. Solid surface free energy values for all plasma-treated surfaces were found to be generally lower than the pristine surfaces, indicating that this process can be used to make similar classes of polymers nonwetting to gallium-based liquid metals.
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Affiliation(s)
- Sachin Babu
- Department of Electrical and Computer Engineering, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, United States
| | - Behnoush Dousti
- Department of Electrical and Computer Engineering, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, United States
| | - Gil Sik Lee
- Department of Electrical and Computer Engineering, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, United States
| | - Jeong-Bong Lee
- Department of Electrical and Computer Engineering, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, United States
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Biocompatibility of SU-8 and Its Biomedical Device Applications. MICROMACHINES 2021; 12:mi12070794. [PMID: 34357204 PMCID: PMC8304786 DOI: 10.3390/mi12070794] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/01/2021] [Accepted: 07/02/2021] [Indexed: 11/16/2022]
Abstract
SU-8 is an epoxy-based, negative-tone photoresist that has been extensively utilized to fabricate myriads of devices including biomedical devices in the recent years. This paper first reviews the biocompatibility of SU-8 for in vitro and in vivo applications. Surface modification techniques as well as various biomedical applications based on SU-8 are also discussed. Although SU-8 might not be completely biocompatible, existing surface modification techniques, such as O2 plasma treatment or grafting of biocompatible polymers, might be sufficient to minimize biofouling caused by SU-8. As a result, a great deal of effort has been directed to the development of SU-8-based functional devices for biomedical applications. This review includes biomedical applications such as platforms for cell culture and cell encapsulation, immunosensing, neural probes, and implantable pressure sensors. Proper treatments of SU-8 and slight modification of surfaces have enabled the SU-8 as one of the unique choices of materials in the fabrication of biomedical devices. Due to the versatility of SU-8 and comparative advantages in terms of improved Young’s modulus and yield strength, we believe that SU-8-based biomedical devices would gain wider proliferation among the biomedical community in the future.
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Pattison TG, Spanu A, Friz AM, Fu Q, Miller RD, Qiao GG. Growing Patterned, Cross-linked Nanoscale Polymer Films from Organic and Inorganic Surfaces Using Ring-Opening Metathesis Polymerization. ACS APPLIED MATERIALS & INTERFACES 2020; 12:4041-4051. [PMID: 31741381 DOI: 10.1021/acsami.9b15852] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The ability to modify substrates with thin polymer films allows for the tailoring of surface properties, and through combination of patterning finds use in a large variety of applications such as electronics and lab-on-chip devices. Although many techniques can be used to afford polymer-modified surfaces such as surface-initiated polymerization or layer-by-layer methodologies, their stability in a wide range of environments as well as their ability to target specific chemistry are critical factors to enable their successful application. In this paper, we report a facile technique in creating nanoscale polymer thin films using solid-state continuous assembly of polymers via ring-opening metathesis polymerization (ssCAPROMP) directly from surfaces functionalized through silanization. Using a polymeric precursor that includes norbornene moieties, a highly dense cross-linked network of polymer can be grown in a bottom-up fashion to afford thin films from an olefin-terminated silanized planar surface. Such nanotechnology affords films retaining the desirable qualities of previously reported methods while, at the same time, being covalently bound to the substrate: they are virtually pinhole free and can be reinitiated multiple times. By combining this process with microcontact printing, patterned films can be created by either the patterned deposition of a catalyst or by controlling the surface silanization chemistry and placement of olefin-terminated and nonreactive silanes. Additionally, patterned ssCAPROMP films were grown from SU-8 by selectively functionalizing the surface through masking and lift-off processes after the silanization step, thereby spatially controlling the surface-initiation, and subsequent polymer film formation. These patterned films expand the capabilities of the CAPROMP process and offer advantages over other film formation techniques in processes where patterned substrates and modified but robust surface chemistries are utilized.
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Affiliation(s)
- Thomas G Pattison
- Polymer Science Group, Department of Chemical Engineering , The University of Melbourne , Parkville , Victoria 3010 , Australia
- International Business Machines-Almaden Research Center , 650 Harry Road , San Jose , California 95110 , United States
| | - Andrea Spanu
- Department of Electrical and Electronic Engineering , University of Cagliari , via Marengo , 09123 Cagliari , Italy
| | - Alexander M Friz
- International Business Machines-Almaden Research Center , 650 Harry Road , San Jose , California 95110 , United States
| | - Qiang Fu
- Polymer Science Group, Department of Chemical Engineering , The University of Melbourne , Parkville , Victoria 3010 , Australia
- The Centre for Technology in Water and Wastewater (CTWW), School of Civil and Environmental Engineering , University of Technology Sydney , Ultimo , NSW 2007 Australia
| | - Robert D Miller
- International Business Machines-Almaden Research Center , 650 Harry Road , San Jose , California 95110 , United States
| | - Greg G Qiao
- Polymer Science Group, Department of Chemical Engineering , The University of Melbourne , Parkville , Victoria 3010 , Australia
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Pan Q, Cao Y, Xue W, Zhu D, Liu W. Picosecond Laser-Textured Stainless Steel Superhydrophobic Surface with an Antibacterial Adhesion Property. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11414-11421. [PMID: 31397568 DOI: 10.1021/acs.langmuir.9b01333] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The pursuit of antibacterial properties on the surfaces of food container, medical equipment, and pharmaceutical tanks has been a compelling challenge for decades. Inspired by the biomimetic superhydrophobic surfaces that have self-cleaning, antifog, antisnow, and reduced bacterial adhesion properties, we use a simple and effective technology of a picosecond laser texturing for the fabrication of a superhydrophobic antibacterial surface on AISI 420 martensitic stainless steel plates. The laser-textured surface with micropapillae patterns with superimposed nanostructures exhibits outstanding in-air superhydrophobic and superaerophilicity underwater, which under the oscillation state resists an adhesion of 99% Escherichia coli and 93% Staphylococcus aureus and has hardly any bacterial adhesion under a stationary state. The comparative experiments verify that the robust air layer and hierarchical micro-nanostructures have come together to comprise the antibacterial mechanism. The laser-textured superhydrophobic surface also exhibits superior anticorrosion and antidestructive abilities with excellent antibacterial durability especially if deep cleaning is carried out after each dipping time in the bacterial suspension, promoting its leading-edge applications in medical, food, and pharmaceutical fields.
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Affiliation(s)
- Qiaofei Pan
- Zhejiang Key Laboratory of Laser Processing Robot, College of Mechanical & Electrical Engineering , Wenzhou University , Wenzhou 325035 , China
| | - Yu Cao
- Institute of Laser and Optoelectronic Intelligent Manufacturing , Wenzhou University , Wenzhou 320000 , China
| | - Wei Xue
- Zhejiang Key Laboratory of Laser Processing Robot, College of Mechanical & Electrical Engineering , Wenzhou University , Wenzhou 325035 , China
| | - Dehua Zhu
- Institute of Laser and Optoelectronic Intelligent Manufacturing , Wenzhou University , Wenzhou 320000 , China
| | - Wenwen Liu
- Zhejiang Key Laboratory of Laser Processing Robot, College of Mechanical & Electrical Engineering , Wenzhou University , Wenzhou 325035 , China
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Beckwith KS, Cooil SP, Wells JW, Sikorski P. Tunable high aspect ratio polymer nanostructures for cell interfaces. NANOSCALE 2015; 7:8438-50. [PMID: 25891641 DOI: 10.1039/c5nr00674k] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Nanoscale topographies and chemical patterns can be used as synthetic cell interfaces with a range of applications including the study and control of cellular processes. Herein, we describe the fabrication of high aspect ratio nanostructures using electron beam lithography in the epoxy-based polymer SU-8. We show how nanostructure geometry, position and fluorescence properties can be tuned, allowing flexible device design. Further, thiol-epoxide reactions were developed to give effective and specific modification of SU-8 surface chemistry. SU-8 nanostructures were made directly on glass cover slips, enabling the use of high resolution optical techniques such as live-cell confocal, total internal reflection and 3D structured illumination microscopy to investigate cell interactions with the nanostructures. Details of cell adherence and spreading, plasma membrane conformation and actin organization in response to high aspect ratio nanopillars and nanolines were investigated. The versatile structural and chemical properties combined with the high resolution cell imaging capabilities of this system are an important step towards the better understanding and control of cell interactions with nanomaterials.
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Affiliation(s)
- Kai Sandvold Beckwith
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway.
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Oh S, Ahn JH, Lee S, Ko H, Seo JM, Goo YS, Cho DID. Light-Controlled Biphasic Current Stimulator IC Using CMOS Image Sensors for High-Resolution Retinal Prosthesis and In Vitro Experimental Results With rd1 Mouse. IEEE Trans Biomed Eng 2015; 62:70-9. [DOI: 10.1109/tbme.2014.2336799] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Yang L, Xin L, Gu W, Tian J, Liao S, Du P, Tong Y, Zhang Y, Lv R, Wang J, Liu X. A new carboxyl-copper-organic framework and its excellent selective absorbability for proteins. J SOLID STATE CHEM 2014. [DOI: 10.1016/j.jssc.2014.05.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Nagaiyanallur VV, Kumar D, Rossi A, Zürcher S, Spencer ND. Tailoring SU-8 surfaces: covalent attachment of polymers by means of nitrene insertion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:10107-10111. [PMID: 25100297 DOI: 10.1021/la501306n] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The photoresist material SU-8 has found a variety of applications in microfabricated systems, such as microelectromechanical (MEMS) and lab-on-a-chip devices. Although the bulk properties of SU-8 are appropriate for many such applications, tailoring its surface-chemical properties has, until now, proven to be challenging but is essential in order to carry out any subsequent self-assembly steps. We have demonstrated that the SU-8 surface can be functionalized by the covalent grafting of a wide variety of polymers by means of nitrene insertion. This is readily achieved with poly(allylamine)-graft-perfluorophenyl azide (PAAm-g-PFPA) or poly(ethyleneimine)-graft-PFPA (PEI-g-PFPA), which can form covalent bonds to both the SU-8 surface and a functionalizing polymer. As examples, poly(diallyl-dimethylammonium chloride) (PDDA) and poly(styrenesulfonate) (PSS) have been covalently linked to a SU-8 substrate, yielding positively and negatively charged surfaces, respectively. The grafted polymers were characterized by means of X-ray photoelectron spectroscopy, and their charge characteristics were confirmed via charged-particle adsorption.
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Affiliation(s)
- Venkataraman V Nagaiyanallur
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich , Wolfgang-Pauli-Strasse 10, CH-8093 Zurich, Switzerland
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Oliver-Calixte NJ, Uba FI, Battle KN, Weerakoon-Ratnayake KM, Soper SA. Immobilization of lambda exonuclease onto polymer micropillar arrays for the solid-phase digestion of dsDNAs. Anal Chem 2014; 86:4447-54. [PMID: 24628008 PMCID: PMC4018173 DOI: 10.1021/ac5002965] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
![]()
The
process of immobilizing enzymes onto solid supports for bioreactions
has some compelling advantages compared to their solution-based counterpart
including the facile separation of enzyme from products, elimination
of enzyme autodigestion, and increased enzyme stability and activity.
We report the immobilization of λ-exonuclease onto poly(methylmethacrylate)
(PMMA) micropillars populated within a microfluidic device for the
on-chip digestion of double-stranded DNA. Enzyme immobilization was
successfully accomplished using 3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling to carboxylic acid
functionalized PMMA micropillars. Our results suggest that the efficiency
for the catalysis of dsDNA digestion using λ-exonuclease, including
its processivity and reaction rate, were higher when the enzyme was
attached to a solid support compared to the free solution digestion.
We obtained a clipping rate of 1.0 × 103 nucleotides
s–1 for the digestion of λ-DNA (48.5 kbp)
by λ-exonuclease. The kinetic behavior of the solid-phase reactor
could be described by a fractal Michaelis–Menten model with
a catalytic efficiency nearly 17% better than the homogeneous solution-phase
reaction. The results from this work will have important ramifications
in new single-molecule DNA sequencing strategies that employ free
mononucleotide identification.
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Affiliation(s)
- Nyoté J Oliver-Calixte
- Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States
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Xue P, Bao J, Chuah YJ, Menon NV, Zhang Y, Kang Y. Protein covalently conjugated SU-8 surface for the enhancement of mesenchymal stem cell adhesion and proliferation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3110-3117. [PMID: 24597829 DOI: 10.1021/la500048z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Cell growing behavior is significantly dependent on the surface chemistry of materials. SU-8 as an epoxy-based negative photoresist is commonly used for fabricating patterned layers in lab-on-a-chip devices. As a hydrophobic material, SU-8 substrate is not favorable for cell culture, and cell attachment on native SU-8 is limited attributed to poor surface biocompatibility. Although physical adsorption of proteins could enhance the cell adhesion, the effect is not durable. In this work, SU-8 surface chemistry is modified by immobilizing fibronectin (FN) and collagen type I (COL I) covalently using (3-aminopropyl)triethoxysilane (APTES) and cross-linker glutaraldehyde (GA) to increase surface biofunctionality. The effectiveness of this surface treatment to improve the adhesion and viability of mesenchymal stem cells (MSCs) is investigated. It is found that the wettability of SU-8 surface can be significantly increased by this chemical modification. In addition, the spreading area of MSCs increases on the SU-8 surfaces with covalently conjugated matrix proteins, as compared to other unmodified SU-8 surface or those coated with proteins simply by physical adsorption. Furthermore, cell proliferation is dramatically enhanced on the SU-8 surfaces modified under the proposed scheme. Therefore, SU-8 surface modification with covalently bound matrix proteins assisted by APTES+GA provides a highly biocompatible interface for the enhanced adhesion, spreading, and proliferation of MSCs.
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Affiliation(s)
- Peng Xue
- School of Chemical and Biomedical Engineering, Nanyang Technological University , 62 Nanyang Drive, 637459 Singapore
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Liu J, Wyatt Shields C, Omofoye O, Lopez GP. Programmable Anisotropic Microparticles for Self-Assembly Applications. ACTA ACUST UNITED AC 2014. [DOI: 10.1557/opl.2014.38] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractColloids with anisotropic shape and properties can enable the assembly of advanced materials otherwise not attainable by microfabrication. In this study, we present a convenient method using common microfabrication tools to generate a diverse array of non-spherical microparticles with well-defined shapes, sizes, electromagnetic properties for self-assembly applications. Projection photolithography onto SU-8 photoresist enabled the production of large aspect ratio microparticles such as cubes, cuboids, cylinders, hexagonal prisms, and parallelepipeds. We characterized these particles to confirm their anisotropic shape and size monodispersity. Fluorescent stains (e.g., Nile red) were mixed into the photoresist prepolymer to enhance the visualization of particle orientation. Particles designed for passive self-assembly were prepared by conventional photolithographic techniques. Particles designed for active assembly were then decorated with metallic patches in precise locations along the surface (e.g., top, side or multiple sides) using electron beam metal evaporation. This metal deposition process can enable orientational control of particles during their assembly in directed fields. After fabrication, large particles (e.g., 1,000 µm3) were released from the substrate via gentle sheer forces, whereas small particles (e.g., 10 µm3) were released by the dissolution of a sacrificial layer underneath the SU-8. Suspending the particles in water with surfactant (or other suitable solvents) provided amenable conditions for their assembly in static or dynamic systems. These conventional methods have the potential to catalyze new research in the fabrication and assembly of anisotropic patchy particles with controllable properties for the hierarchical development of self-assembled micromirrors, biosensors, and photonic crystals as examples.
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Jackson JM, Witek MA, Hupert ML, Brady C, Pullagurla S, Kamande J, Aufforth RD, Tignanelli CJ, Torphy RJ, Yeh JJ, Soper SA. UV activation of polymeric high aspect ratio microstructures: ramifications in antibody surface loading for circulating tumor cell selection. LAB ON A CHIP 2014; 14:106-17. [PMID: 23900277 PMCID: PMC4182936 DOI: 10.1039/c3lc50618e] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The need to activate thermoplastic surfaces using robust and efficient methods has been driven by the fact that replication techniques can be used to produce microfluidic devices in a high production mode and at low cost, making polymer microfluidics invaluable for in vitro diagnostics, such as circulating tumor cell (CTC) analysis, where device disposability is critical to mitigate artifacts associated with sample carryover. Modifying the surface chemistry of thermoplastic devices through activation techniques can be used to increase the wettability of the surface or to produce functional scaffolds to allow for the covalent attachment of biologics, such as antibodies for CTC recognition. Extensive surface characterization tools were used to investigate UV activation of various surfaces to produce uniform and high surface coverage of functional groups, such as carboxylic acids in microchannels of different aspect ratios. We found that the efficiency of the UV activation process is highly dependent on the microchannel aspect ratio and the identity of the thermoplastic substrate. Colorimetric assays and fluorescence imaging of UV-activated microchannels following EDC/NHS coupling of Cy3-labeled oligonucleotides indicated that UV-activation of a PMMA microchannel with an aspect ratio of ~3 was significantly less efficient toward the bottom of the channel compared to the upper sections. This effect was a consequence of the bulk polymer's damping of the modifying UV radiation due to absorption artifacts. In contrast, this effect was less pronounced for COC. Moreover, we observed that after thermal fusion bonding of the device's cover plate to the substrate, many of the generated functional groups buried into the bulk rendering them inaccessible. The propensity of this surface reorganization was found to be higher for PMMA compared to COC. As an example of the effects of material and microchannel aspect ratios on device functionality, thermoplastic devices for the selection of CTCs from whole blood were evaluated, which required the immobilization of monoclonal antibodies to channel walls. From our results, we concluded the CTC yield and purity of isolated CTCs were dependent on the substrate material with COC producing the highest clinical yields for CTCs as well as better purities compared to PMMA.
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SU-8 photolithography on reactive plasma thin-films: coated microwells for peptide display. Colloids Surf B Biointerfaces 2013; 108:313-21. [DOI: 10.1016/j.colsurfb.2013.03.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Revised: 03/03/2013] [Accepted: 03/05/2013] [Indexed: 11/18/2022]
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Bhimji A, Zaragoza AA, Live LS, Kelley SO. Electrochemical enzyme-linked immunosorbent assay featuring proximal reagent generation: detection of human immunodeficiency virus antibodies in clinical samples. Anal Chem 2013; 85:6813-9. [PMID: 23758505 DOI: 10.1021/ac4009429] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe a simple electrochemical immunoassay for human immunodeficiency virus (HIV) antibody detection that localizes capture and detection reagents in close proximity to a microelectrode. Antigenic peptides from HIV-1 gp41 or HIV-2 gp36 were covalently attached to a SU-8 substrate that also presented a template for the deposition of three-dimensional microelectrodes. The detection of HIV antibodies was achieved with an electrochemical immunoassay where an alkaline phosphatase conjugated secondary antibody reacts with p-aminophenyl phosphate (pAPP) to produce a redox-active product, p-aminophenol. The current derived from the oxidation of the reporter group increased linearly over a wide antibody concentration range (0.001-1 μg mL(-1)), with a detection limit of 1 ng mL(-1) (6.7 pM) for both HIV-1 and HIV-2. This level of sensitivity is clinically relevant, and the feasibility of this approach for clinical sample testing was also evaluated with HIV clinical patient samples, with excellent performance observed compared against a commercially available gold standard. This approach was used to develop the first electrochemical enzyme-linked immunosorbent assay (ELISA) to detect HIV in clinical samples, and excellent performance relative to a gold standard test was achieved.
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Affiliation(s)
- Alyajahan Bhimji
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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Ortega FJ, Bañuls MJ, Sanza FJ, Laguna MF, Holgado M, Casquel R, Barrios CA, López-Romero D, Maquieira Á, Puchades R. Development of a versatile biotinylated material based on SU-8. J Mater Chem B 2013; 1:2750-2756. [DOI: 10.1039/c3tb20323a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Aekbote BL, Jacak J, Schütz GJ, Csányi E, Szegletes Z, Ormos P, Kelemen L. Aminosilane-based functionalization of two-photon polymerized 3D SU-8 microstructures. Eur Polym J 2012. [DOI: 10.1016/j.eurpolymj.2012.06.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Ortega FJ, Bañuls MJ, Sanza FJ, Casquel R, Laguna MF, Holgado M, López-Romero D, Barrios CA, Maquieira Á, Puchades R. Biomolecular Interaction Analysis of Gestrinone-anti-Gestrinone Using Arrays of High Aspect Ratio SU-8 Nanopillars. BIOSENSORS-BASEL 2012; 2:291-304. [PMID: 25585931 PMCID: PMC4263551 DOI: 10.3390/bios2030291] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 08/02/2012] [Accepted: 08/13/2012] [Indexed: 01/25/2023]
Abstract
In this paper, label-free biosensing for antibody screening by periodic lattices of high-aspect ratio SU-8 nano-pillars (BICELLs) is presented. As a demonstration, the determination of anti-gestrinone antibodies from whole rabbit serum is carried out, and for the first time, the dissociation constant (KD = 6 nM) of antigen-antibody recognition process is calculated using this sensing system. After gestrinone antigen immobilization on the BICELLs, the immunorecognition was performed. The cells were interrogated vertically by using micron spot size Fourier transform visible and IR spectrometry (FT-VIS-IR), and the dip wavenumber shift was monitored. The biosensing assay exhibited good reproducibility and sensitivity (LOD = 0.75 ng/mL).
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Affiliation(s)
- Francisco J Ortega
- Centro de Reconocimiento Molecular y Desarrollo Tecnológico, Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, Valencia 46022, Spain.
| | - María-José Bañuls
- Centro de Reconocimiento Molecular y Desarrollo Tecnológico, Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, Valencia 46022, Spain.
| | - Francisco J Sanza
- Centro Láser, Universidad Politécnica de Madrid, Campus Sur, Madrid 28031, Spain.
| | - Rafael Casquel
- Centro Láser, Universidad Politécnica de Madrid, Campus Sur, Madrid 28031, Spain.
| | - María Fe Laguna
- Centro Láser, Universidad Politécnica de Madrid, Campus Sur, Madrid 28031, Spain.
| | - Miguel Holgado
- Centro Láser, Universidad Politécnica de Madrid, Campus Sur, Madrid 28031, Spain.
| | - David López-Romero
- Instituto de Sistemas Optoelectrónicos y Microtecnología, Universidad Politécnica de Madrid, ETSI de Telecomunicación, Ciudad Universitaria s/n, Madrid 28040, Spain.
| | - Carlos A Barrios
- Instituto de Sistemas Optoelectrónicos y Microtecnología, Universidad Politécnica de Madrid, ETSI de Telecomunicación, Ciudad Universitaria s/n, Madrid 28040, Spain.
| | - Ángel Maquieira
- Centro de Reconocimiento Molecular y Desarrollo Tecnológico, Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, Valencia 46022, Spain.
| | - Rosa Puchades
- Centro de Reconocimiento Molecular y Desarrollo Tecnológico, Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, Valencia 46022, Spain.
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Yu BY, Hu SW, Sun YM, Lee YT, Young TH. Modulating the Activities of Human Mesenchymal Stem Cells (hMSCs) and C3A/HepG2 Hepatoma Cells by Modifying the Surface Characteristics of Poly(3-hydroxybutyrate-co-3-hydroxyhexnoate) (PHBHHx). JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 20:1275-93. [DOI: 10.1163/156856209x452999] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Bo-Yi Yu
- a Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan 100, Republic of China; Department of Chemical Engineering and Materials Science, Yuan Ze University Chung-Li, Taoyuan, Taiwan 320, Republic of China
| | - Si-Wei Hu
- b Department of Chemical Engineering and Materials Science, Yuan Ze University Chung-Li, Taoyuan, Taiwan 320, Republic of China
| | - Yi-Ming Sun
- c Department of Chemical Engineering and Materials Science, Yuan Ze University Chung-Li, Taoyuan, Taiwan 320, Republic of China; Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Chung-Li, Taoyuan, Taiwan 320, Republic of China; R&D Center for Membrane Technology, Chung Yuan University, Chung-Li, Taoyuan, Taiwan 320, Republic of China
| | - Yu-Tsang Lee
- d Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan 100, Republic of China; Department of Orthopedic Surgery, Min-Sheng General Hospital, Taoyuan, Taiwan 330, Republic of China
| | - Tai-Horng Young
- e Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan 100, Republic of China
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Jain T, Papas A, Jadhav A, McBride R, Saez E. In situ electroporation of surface-bound siRNAs in microwell arrays. LAB ON A CHIP 2012; 12:939-47. [PMID: 22245984 PMCID: PMC3392120 DOI: 10.1039/c2lc20931d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Gene silencing using RNA interference (RNAi) has become a prominent biological tool for gene annotation, pathway analysis, and target discovery in mammalian cells. High-throughput screens conducted using whole-genome siRNA libraries have uncovered rich sets of new genes involved in a variety of biological processes and cellular models of disease. However, high-throughput RNAi screening is not yet a mainstream tool in life science research because current screening platforms are expensive and onerous. Miniaturizing the RNAi screening platform to reduce cost and increase throughput will enable its widespread use and harness its potential for rapid genome annotation. With this aim, we have combined semi-conductor microfabrication and nanolitre dispensing techniques to develop miniaturized electroporation-ready microwell arrays loaded with siRNA molecules in which multiplexed gene knockdown can be achieved. Arrays of microwells are created using high-aspect ratio biocompatible photoresists on optically transparent and conductive Indium-Tin Oxide (ITO) substrates with integrated micro-electrodes to enable in situ electroporation. Non-contact inkjet microarraying allows precise dispensing of nanolitre volumes into the microwell structures. We have achieved parallel electroporation of multiple mammalian cells cultured in these microwell arrays and observed efficient knockdown of genes with surface-bound, printed siRNAs. Further integration of microfabrication and non-contact nanolitre dispensing techniques described here may enable single-substrate whole-genome siRNA screening in mammalian cells.
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Zhang Y, Ren L, Tu Q, Wang X, Liu R, Li L, Wang JC, Liu W, Xu J, Wang J. Fabrication of Reversible Poly(dimethylsiloxane) Surfaces via Host–Guest Chemistry and Their Repeated Utilization in Cardiac Biomarker Analysis. Anal Chem 2011; 83:9651-9. [DOI: 10.1021/ac202517x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yanrong Zhang
- Colleges of Science and Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China
| | - Li Ren
- Colleges of Science and Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China
| | - Qin Tu
- Colleges of Science and Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China
| | - Xueqin Wang
- Colleges of Science and Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China
| | - Rui Liu
- Colleges of Science and Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China
| | - Li Li
- Colleges of Science and Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China
| | - Jian-Chun Wang
- Colleges of Science and Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China
| | - Wenming Liu
- Colleges of Science and Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China
| | - Juan Xu
- Colleges of Science and Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China
| | - Jinyi Wang
- Colleges of Science and Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China
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Walther F, Drobek T, Gigler AM, Hennemeyer M, Kaiser M, Herberg H, Shimitsu T, Morfill GE, Stark RW. Surface hydrophilization of SU-8 by plasma and wet chemical processes. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3515] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Gunn NM, Bachman M, Li GP, Nelson EL. Fabrication and biological evaluation of uniform extracellular matrix coatings on discontinuous photolithography generated micropallet arrays. J Biomed Mater Res A 2010; 95:401-12. [PMID: 20648537 PMCID: PMC2981065 DOI: 10.1002/jbm.a.32854] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The recent identification of rare cell populations within tissues that are associated with specific biological behaviors, for example, progenitor cells, has illuminated a limitation of current technologies to study such adherent cells directly from primary tissues. The micropallet array is a recently developed technology designed to address this limitation by virtue of its capacity to isolate and recover single adherent cells on individual micropallets. The capacity to apply this technology to primary tissues and cells with restricted growth characteristics, particularly adhesion requirements, is critically dependent on the capacity to generate functional extracellular matrix (ECM) coatings. The discontinuous nature of the micropallet array surface provides specific constraints on the processes for generating the desired ECM coatings that are necessary to achieve the full functional capacity of the micropallet array. We have developed strategies, reported herein, to generate functional coatings with various ECM protein components: fibronectin, EHS tumor basement membrane extract, collagen, and laminin-5; confirmed by evaluation for rapid cellular adherence of four dissimilar cell types: fibroblast, breast epithelial, pancreatic epithelial, and myeloma. These findings are important for the dissemination and expanded use of micropallet arrays and similar microtechnologies requiring the integrated use of ECM protein coatings to promote cellular adherence.
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Affiliation(s)
- Nicholas M. Gunn
- School of Engineering, Department of Biomedical Engineering, University of California at Irvine, Irvine, CA 92697
| | - Mark Bachman
- School of Engineering, Department of Electrical and Computer Science, University of California at Irvine, Irvine, CA 92697
- School of Engineering, Integrated Nanosystems Research Facility, University of California at Irvine, Irvine, CA 92697
- School of Engineering, California Institute for Telecommunications and Information Technology (CalIT), University of California at Irvine, Irvine, CA 92697
| | - Guann-Pyng Li
- School of Engineering, Department of Electrical and Computer Science, University of California at Irvine, Irvine, CA 92697
- School of Engineering, Integrated Nanosystems Research Facility, University of California at Irvine, Irvine, CA 92697
- School of Engineering, California Institute for Telecommunications and Information Technology (CalIT), University of California at Irvine, Irvine, CA 92697
| | - Edward L. Nelson
- School of Medicine, Department of Medicine, Division of Hematology/Oncology, University of California at Irvine, Irvine, CA 92697
- Institute for Immunology, University of California at Irvine, Irvine, CA 92697
- School of Biological Sciences, Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, CA 92697
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25
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Yang L, Li L, Tu Q, Ren L, Zhang Y, Wang X, Zhang Z, Liu W, Xin L, Wang J. Photocatalyzed Surface Modification of Poly(dimethylsiloxane) with Polysaccharides and Assay of Their Protein Adsorption and Cytocompatibility. Anal Chem 2010; 82:6430-9. [DOI: 10.1021/ac100544x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Linyan Yang
- Colleges of Science, Life Science, and Animal Medicine and Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, People’s Republic of China
| | - Li Li
- Colleges of Science, Life Science, and Animal Medicine and Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, People’s Republic of China
| | - Qin Tu
- Colleges of Science, Life Science, and Animal Medicine and Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, People’s Republic of China
| | - Li Ren
- Colleges of Science, Life Science, and Animal Medicine and Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, People’s Republic of China
| | - Yanrong Zhang
- Colleges of Science, Life Science, and Animal Medicine and Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, People’s Republic of China
| | - Xueqin Wang
- Colleges of Science, Life Science, and Animal Medicine and Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, People’s Republic of China
| | - Zhiyun Zhang
- Colleges of Science, Life Science, and Animal Medicine and Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, People’s Republic of China
| | - Wenming Liu
- Colleges of Science, Life Science, and Animal Medicine and Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, People’s Republic of China
| | - Liangliang Xin
- Colleges of Science, Life Science, and Animal Medicine and Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, People’s Republic of China
| | - Jinyi Wang
- Colleges of Science, Life Science, and Animal Medicine and Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, People’s Republic of China
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26
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Contact printing of arrayed microstructures. Anal Bioanal Chem 2010; 397:3377-85. [PMID: 20425106 DOI: 10.1007/s00216-010-3728-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 04/06/2010] [Accepted: 04/06/2010] [Indexed: 12/16/2022]
Abstract
A novel contact printing method utilizing a sacrificial layer of polyacrylic acid (PAA) was developed to selectively modify the upper surfaces of arrayed microstructures. The method was characterized by printing polystyrene onto SU-8 microstructures to create an improved substrate for a cell-based microarray platform. Experiments measuring cell growth on SU-8 arrays modified with polystyrene and fibronectin demonstrated improved growth of NIH 3T3 (93% vs. 38%), HeLa (97% vs. 77%), and HT1080 (76% vs. 20%) cells relative to that for the previously used coating method. In addition, use of the PAA sacrificial layer permitted the printing of functionalized polystyrene, carboxylate polystyrene nanospheres, and silica nanospheres onto the arrays in a facile manner. Finally, a high concentration of extracellular matrix materials (ECM), such as collagen (5 mg/mL) and gelatin (0.1%), was contact-printed onto the array structures using as little as 5 microL of the ECM reagent and without the formation of a continuous film bridge across the microstructures. Murine embryonic stem cells cultured on arrays printed with this gelatin hydrogel remained in an undifferentiated state indicating an adequate surface gelatin layer to maintain these cells over time.
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A photoimmobilizable sulfobetaine-based polymer for a nonbiofouling surface. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2010; 30:316-322. [DOI: 10.1016/j.msec.2009.11.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 11/10/2009] [Accepted: 11/13/2009] [Indexed: 10/20/2022]
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28
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Wong I, Ho CM. Surface molecular property modifications for poly(dimethylsiloxane) (PDMS) based microfluidic devices. MICROFLUIDICS AND NANOFLUIDICS 2009; 7:291-306. [PMID: 20357909 PMCID: PMC2847407 DOI: 10.1007/s10404-009-0443-4] [Citation(s) in RCA: 281] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2008] [Accepted: 03/31/2009] [Indexed: 05/02/2023]
Abstract
Fast advancements of microfabrication processes in past two decades have reached to a fairly matured stage that we can manufacture a wide range of microfluidic devices. At present, the main challenge is the control of nanoscale properties on the surface of lab-on-a-chip to satisfy the need for biomedical applications. For example, poly(dimethylsiloxane) (PDMS) is a commonly used material for microfluidic circuitry, yet the hydrophobic nature of PDMS surface suffers serious nonspecific protein adsorption. Thus the current major efforts are focused on surface molecular property treatments for satisfying specific needs in handling macro functional molecules. Reviewing surface modifications of all types of materials used in microfluidics will be too broad. This review will only summarize recent advances in nonbiofouling PDMS surface modification strategies applicable to microfluidic technology and classify them into two main categories: (1) physical approach including physisorption of charged or amphiphilic polymers and copolymers, as well as (2) chemical approach including self assembled monolayer and thick polymer coating. Pros and cons of a collection of available yet fully exploited surface modification methods are briefly compared among subcategories.
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Affiliation(s)
- Ieong Wong
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, USA,
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29
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Ainslie KM, Desai TA. Microfabricated implants for applications in therapeutic delivery, tissue engineering, and biosensing. LAB ON A CHIP 2008; 8:1864-78. [PMID: 18941687 PMCID: PMC2970504 DOI: 10.1039/b806446f] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
By adapting microfabrication techniques originally developed in the microelectronics industry novel devices for drug delivery, tissue engineering and biosensing have been engineered for in vivo use. Implant microfabrication uses a broad range of techniques including photolithography, and micromachining to create devices with features ranging from 0.1 to hundreds of microns with high aspect ratios and precise features. Microfabrication offers device feature scale that is relevant to the tissues and cells to which they are applied, as well as offering ease of en masse fabrication, small device size, and facile incorporation of integrated circuit technology. Utilizing these methods, drug delivery applications have been developed for in vivo use through many delivery routes including intravenous, oral, and transdermal. Additionally, novel microfabricated tissue engineering approaches propose therapies for the cardiovascular, orthopedic, and ocular systems, among others. Biosensing devices have been designed to detect a variety of analytes and conditions in vivo through both enzymatic-electrochemical reactions and sensor displacement through mechanical loading. Overall, the impact of microfabricated devices has had an impact over a broad range of therapies and tissues. This review addresses many of these devices and highlights their fabrication as well as discusses materials relevant to microfabrication techniques.
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Affiliation(s)
- Kristy M. Ainslie
- Department of Bioengineering and Therapeutic Sciences; Department of Physiology University of California, San Francisco
| | - Tejal A. Desai
- Department of Bioengineering and Therapeutic Sciences; Department of Physiology University of California, San Francisco
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Blagoi G, Keller S, Persson F, Boisen A, Jakobsen MH. Photochemical modification and patterning of SU-8 using anthraquinone photolinkers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:9929-9932. [PMID: 18710270 DOI: 10.1021/la800948w] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Bioactive protein patterns and microarrays achieved by selective localization of biomolecules find various applications in biosensors, bio-microelectromechanical systems (bio-MEMS), and in basic protein studies. In this paper we describe simple photochemical methods to fabricate two-dimensional patterns on a Novolac A derivative polymer (SU-8) and, subsequently, their functionalization with biomolecules. Anthraquinone (AQ) derivatives are used to chemically modify and pattern SU-8 surfaces. Features as small as 20 mum are obtained when using uncollimated light. The X-Y spatial resolution of micropatterned AQ molecules is improved to 1.5 mum when a collimated light source is used. This micropatterning process will be important for the functionalization of MEMS-based biosensors. The method saves several processing steps and can be integrated in cleanroom fabrication thus avoiding contamination of the sensor surfaces.
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Affiliation(s)
- Gabriela Blagoi
- Department of Micro and Nanotechnology, Technical University of Denmark, DTU Nanotech, Kongens Lyngby, Denmark.
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Ainslie KM, Kraning CM, Desai TA. Microfabrication of an asymmetric, multi-layered microdevice for controlled release of orally delivered therapeutics. LAB ON A CHIP 2008; 8:1042-7. [PMID: 18584077 PMCID: PMC2969854 DOI: 10.1039/b800604k] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The creation of an oral drug delivery platform to administer chemotherapeutic agents effectively can not only increase patient compliance, but also potentially diminish drug toxicity. A microfabricated device offers advantages over conventional drug delivery technology. Here we describe the development of a multi-layered polymeric drug-loaded microfabricated device (microdevice) for the oral delivery of therapeutics, which offers unidirectional release of multiple therapeutics. The imaging and release of therapeutics from the multi-layered device was performed with three different fluorescently labeled albumins. The release of insulin and chemotherapeutic camptothecin was also observed to be released in a controlled manner over the course of 180 min in vitro. Furthermore, asymmetric delivery was shown to concentrate drug at the device/cell interface, wherein 10 times more drug permeated an intestinal epithelial cell monolayer, compared to unprotected drug-loaded hydrogels. The bioactivity of the released chemotherapeutic was shown with cytostasis of colorectal adenocarcinoma cells. Cytostasis of drug loaded hydrogels was significantly higher than control empty hydrogel laden microdevices. Our results conclude that microfabrication of a hydrogel laden microdevice leads to a viable oral delivery platform for chemotherapeutics.
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Affiliation(s)
- Kristy M. Ainslie
- Department of Bioengineering and Therapeutic Sciences; Department of Physiology University of California, San Francisco; San Francisco, CA 64158-2330 (USA)
| | - Casey M. Kraning
- National Science Foundation Research Experience for Undergraduates; Summer Research Training Program; University of California, San Francisco; San Francisco, CA; 94158 (USA) Chemistry Department; Butler University; Indianapolis, IN; 46208 (USA)
| | - Tejal A. Desai
- Department of Bioengineering and Therapeutic Sciences; Department of Physiology University of California, San Francisco; San Francisco, CA 64158-2330 (USA)
- Corresponding Author: Tejal A. Desai, Department of Physiology University of California, San Francisco, San Francisco, CA 64158-2330, Box 2520, Byers Hall Rm 203C,
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Suspension arrays of hydrogel microparticles prepared by photopatterning for multiplexed protein-based bioassays. Biomed Microdevices 2008; 10:813-822. [DOI: 10.1007/s10544-008-9196-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Goda T, Matsuno R, Konno T, Takai M, Ishihara K. Photografting of 2-methacryloyloxyethyl phosphorylcholine from polydimethylsiloxane: Tunable protein repellency and lubrication property. Colloids Surf B Biointerfaces 2008; 63:64-72. [DOI: 10.1016/j.colsurfb.2007.11.014] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Revised: 11/08/2007] [Accepted: 11/11/2007] [Indexed: 11/30/2022]
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34
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Tao SL, Popat KC, Norman JJ, Desai TA. Surface modification of SU-8 for enhanced biofunctionality and nonfouling properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:2631-2636. [PMID: 18275232 DOI: 10.1021/la703066z] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
SU-8 is a chemically amplified, epoxy-based negative photoresist typically used for producing ultrathick resist layers during device manufacturing in the semiconductor industry. As a simple resist, SU-8 has garnered attention as a possible material for a variety of biomedical applications, including tissue engineering, drug delivery, as well as cell-based screening and sensing. However, as a hydrophobic material, the use of SU-8 is limited due to a high degree of nonspecific adsorption of biomolecules, as well as limited cell attachment. In this work, surface chemistry is utilized to modify the SU-8 surface by covalently attaching poly(ethylene glycol) (PEG) to increase biofunctionality and improve its nonfouling properties. Different molecular weights and concentrations of PEG were used to form films of various grafting densities on SU-8 surfaces. X-ray photoelectron spectroscopy (XPS) was used to verify the presence of PEG moieties on the SU-8 surface. High-resolution C1s spectra show that, with an increase in concentration and immobilization time, the grafting density of PEG also increases. Further, a standard overlayer model was used to calculate the thickness of the PEG films formed. The effect of PEG-modified SU-8 was examined in terms of protein adsorption on the surface and fibroblast-surface interactions.
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Affiliation(s)
- Sarah L Tao
- Department of Physiology, Division of Bioengineering, University of California-San Francisco, San Francisco, California 94158, USA
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Pai JH, Wang Y, Salazar GT, Sims CE, Bachman M, Li GP, Allbritton NL. Photoresist with low fluorescence for bioanalytical applications. Anal Chem 2007; 79:8774-80. [PMID: 17949059 DOI: 10.1021/ac071528q] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The negative photoresist SU-8 has found widespread use as a material in the fabrication of microelectrical-mechanical systems (MEMS). Although SU-8 has been utilized as a structural material for biological MEMS, a number of SU-8 properties limit its application in these bioanalytical devices. These attributes include its brittleness, nonspecific adsorption of biomolecules, and high fluorescence in the visible wavelengths. In addition, native SU-8 is a poor substrate for cellular adhesion. Photoresists composed of resins with epoxide side groups and photoacids were screened for their ability to serve as a low-fluorescence photoresist with sufficient resolution to generate microstructures with dimensions of 5-10 microm. The fluorescence of structures formed from 1002F photoresist (1002F resin combined with triarylsulfonium hexafluoroantimonate salts) was as much as 10 times less fluorescent than similar SU-8 microstructures. The absorbance of 1002F in the visible wavelengths was also substantially lower than that of SU-8. Microstructures or pallets with an aspect ratio as high as 4:1 could be formed permitting 1002F to be used as a structural material in the fabrication of arrays of pallets for sorting adherent cells. Several different cell types were able to adhere to native 1002F surfaces, and the viability of these cells was excellent. As with SU-8, 1002F has a weak adhesion to glass, a favorable attribute when the pallet arrays are used to sort adherent cells. A threshold, laser pulse energy of 3.5 microJ was required to release individual 50 microm, 1002F pallets from an array. Relative to SU-8, 1002F photoresist offers substantial improvements as a substrate in bioanalytical devices and is likely to find widespread use in BioMEMS.
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Affiliation(s)
- Jeng-Hao Pai
- Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697, USA
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