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Kimura R, Noda D, Liu Z, Shi W, Akutsu R, Tagaya M. Biological Surface Layer Formation on Bioceramic Particles for Protein Adsorption. Biomimetics (Basel) 2024; 9:347. [PMID: 38921227 PMCID: PMC11201679 DOI: 10.3390/biomimetics9060347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 05/28/2024] [Accepted: 06/05/2024] [Indexed: 06/27/2024] Open
Abstract
In the biomedical fields of bone regenerative therapy, the immobilization of proteins on the bioceramic particles to maintain their highly ordered structures is significantly important. In this review, we comprehensively discussed the importance of the specific surface layer, which can be called "non-apatitic layer", affecting the immobilization of proteins on particles such as hydroxyapatite and amorphous silica. It was suggested that the water molecules and ions contained in the non-apatitic layer can determine and control the protein immobilization states. In amorphous silica particles, the direct interactions between proteins and silanol groups make it difficult to immobilize the proteins and maintain their highly ordered structures. Thus, the importance of the formation of a surface layer consisting of water molecules and ions (i.e., a non-apatitic layer) on the particle surfaces for immobilizing proteins and maintaining their highly ordered structures was suggested and described. In particular, chlorine-containing amorphous silica particles were also described, which can effectively form the surface layer of protein immobilization carriers. The design of the bio-interactive and bio-compatible surfaces for protein immobilization while maintaining the highly ordered structures will improve cell adhesion and tissue formation, thereby contributing to the construction of social infrastructures to support super-aged society.
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Affiliation(s)
| | | | | | | | | | - Motohiro Tagaya
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka 940-2188, Japan
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Kimura R, Chatani S, Inui M, Motozuka S, Liu Z, Tagaya M. Control of Biological Surface States on Chlorine-Doped Amorphous Silica Particles and Their Effective Absorptive Ability for Antibody Protein. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:8939-8949. [PMID: 38635896 DOI: 10.1021/acs.langmuir.4c00114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Amorphous silica particles (ASPs) have low biotoxicity and are used in foodstuffs; however, the adsorption states of proteins on their surfaces have not yet been clarified. If the adsorption states can be clarified and controlled, then a wide range of biological and medical applications can be expected. The conventional amorphous silica particles have the problem of protein adsorption due to the strong interaction with their dense silanol groups and denaturation. In this study, the surfaces of amorphous silica particles with a lower silanol group density were modified with a small amount of chlorine during the synthesis process to form a specific surface layer by adsorbing water molecules and ions in the biological fluid, thereby controlling the protein adsorption state. Specifically, the hydration state on the surface of the amorphous silica particles containing trace amounts of chlorine was evaluated, and the surface layer (especially the hydration state) for the adsorption of antibody proteins while maintaining their steric structures was evaluated and discussed. The results showed that the inclusion of trace amounts of chlorine increased the silanol groups and Si-Cl bonds in the topmost surface layer of the particles, thereby inducing the adsorption of ions and water molecules in the biological fluid. Then, it was found that a novel surface layer was formed by the effective adsorption of Na and phosphate ions, which would change the proportion of the components in the hydration layer. In particular, the proportion of the free water component increased by 21% with the doping of chlorine. Antibody proteins were effectively adsorbed on the particles doped with trace amounts of chlorine, and their steric adsorption states were evaluated. It was found that the proteins were clearly adsorbed and maintained the steric state of their secondary structure. In the immunoreactivity tests using streptavidin and biotin, biotin bound to the chlorine-doped particles showed efficient reactivity. In conclusion, this study is the first to discover the surface layer of the amorphous silica particles to maintain the steric structures of adsorbed proteins, which is expected to be used as a carrier particle for antibody test kits and immunochromatography.
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Affiliation(s)
- Reo Kimura
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka 940-2188, Japan
| | - Sunao Chatani
- Production Department, Ohara Quartz, Minato 1850, Wakayama, Wakayama 640-8404, Japan
| | - Masahiko Inui
- Production Department, Ohara Quartz, Minato 1850, Wakayama, Wakayama 640-8404, Japan
| | - Satoshi Motozuka
- Department of Materials Science and Engineering, Kyushu Institute of Technology, Sensuicho 1-1, Tobata-ku, Kitakyushu 804-8550, Japan
| | - Zizhen Liu
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka 940-2188, Japan
| | - Motohiro Tagaya
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka 940-2188, Japan
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Pasquardini L, Vanzetti L, Canteri R, Cennamo N, Arcadio F, Perri C, D'Agostino G, Pitruzzella R, Rovida R, Chiodi A, Zeni L. Optimization of the immunorecognition layer towards Brucella sp. on gold surface for SPR platform. Colloids Surf B Biointerfaces 2023; 231:113577. [PMID: 37797466 DOI: 10.1016/j.colsurfb.2023.113577] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 08/08/2023] [Accepted: 09/30/2023] [Indexed: 10/07/2023]
Abstract
A successful immunosensor is characterized by a proper antibody immobilization and orientation in order to enhance the antigen recognition. In this work, a thorough characterization of the antibody functionalized gold surface is performed to set up the best conditions to implement in an optical platform for the detection of Brucella sp. Two different strategies are evaluated, based on a random immobilization and on an oriented one: a direct antibody immobilization on carboxylic mixed polyethylene (PEG) self-assembled monolayer (SAM) or only carboxylic PEG SAM interface is compared to an oriented immobilization on a layer of protein G on the same PEG SAM interfaces. X-ray Photoelectron Spectroscopy (XPS), Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and contact angle (CA) are used to chemically characterize the gold functionalized surface and ToF-SIMS is also used to confirm the right antibody orientation. Optical characterization is applied to monitor the functionalization steps and fluorescence measurements are used to set up the proper experimental conditions and also to detect Brucella bacteria on the surface. Best results are obtained with a 10 ng/μl incubation solution of antibody immobilized, in an oriented way, on a mixed PEG SAM interface.
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Affiliation(s)
| | - Lia Vanzetti
- Fondazione Bruno Kessler (FBK), Micro Nano Facility (MNF), Via Sommarive 18, 38123 Trento, Italy
| | - Roberto Canteri
- Fondazione Bruno Kessler (FBK), Micro Nano Facility (MNF), Via Sommarive 18, 38123 Trento, Italy
| | - Nunzio Cennamo
- Department of Engineering, University of Campania "L. Vanvitelli", Via Roma 29, 81031 Aversa, Italy
| | - Francesco Arcadio
- Department of Engineering, University of Campania "L. Vanvitelli", Via Roma 29, 81031 Aversa, Italy
| | - Chiara Perri
- Moresense srl, Filarete Foundation, Viale Ortles 22/4, 20139 Milano, Italy
| | | | - Rosalba Pitruzzella
- Department of Engineering, University of Campania "L. Vanvitelli", Via Roma 29, 81031 Aversa, Italy
| | - Riccardo Rovida
- Department of Engineering, University of Campania "L. Vanvitelli", Via Roma 29, 81031 Aversa, Italy
| | - Alessandro Chiodi
- Moresense srl, Filarete Foundation, Viale Ortles 22/4, 20139 Milano, Italy
| | - Luigi Zeni
- Department of Engineering, University of Campania "L. Vanvitelli", Via Roma 29, 81031 Aversa, Italy.
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Atomistic simulations for investigation of substrate effects on lipid in-source fragmentation in secondary ion mass spectrometry. Biointerphases 2023; 18:011003. [PMID: 36759318 DOI: 10.1116/6.0002298] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
In beam-based ionization methods, the substrate plays an important role on the desorption mechanism of molecules from surfaces. Both the specific orientation that a molecule adopts at a surface and the strength of the molecule-surface interaction can greatly influence desorption processes, which in turn will affect the ion yield and the degree of in-source fragmentation of a molecule. In the beam-based method of secondary ion mass spectrometry (SIMS), in-source fragmentation can be significant and molecule specific due to the hard ionization method of using a primary ion beam for molecule desorption. To investigate the role of the substrate on orientation and in-source fragmentation, we have used atomistic simulations-molecular dynamics in combination with density functional theory calculations-to explore the desorption of a sphingolipid (palmitoylsphingomyelin) from a model surface (gold). We then compare SIMS data from this model system to our modeling findings. Using this approach, we found that the combined adsorption and binding energy of certain bonds associated with the headgroup fragments (C3H8N+, C5H12N+, C5H14NO+, and C5H15PNO4 +) was a good predictor for fragment intensities (as indicated by relative ion yields). This is the first example where atomistic simulations have been applied in beam-based ionization of lipids, and it presents a new approach to study biointerfacial lipid ordering effects on SIMS imaging.
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Popov A, Lisyte V, Kausaite-Minkstimiene A, Bernotiene E, Ramanaviciene A. Experimental Evaluation of Quantum Dots and Antibodies Conjugation by Surface Plasmon Resonance Spectroscopy. Int J Mol Sci 2022; 23:ijms232012626. [PMID: 36293491 PMCID: PMC9603974 DOI: 10.3390/ijms232012626] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Revised: 10/15/2022] [Accepted: 10/18/2022] [Indexed: 11/16/2022] Open
Abstract
The application of antibody-functionalized quantum dots (QDs) in different areas has been widely described in the literature. However, a standard routine method for obtaining information on the conjugation efficiency of QDs with antibodies in terms of the interaction of the functionalized QDs with a specific antigen is still lacking. Herein, surface plasmon resonance (SPR) spectroscopy is proposed for this purpose. Gold-coated SPR sensor disks were modified with a self-assembled monolayer of 11-mercaptoundecanoic acid, and carbodiimide cross-linker chemistry was used to covalently immobilize the CD44 biomarker on the premodified surface (Au/CD44). Meanwhile, QDs functionalized with amine-derivatized polyethylene glycol (PEG) (QDs-NH2) were chosen for conjugation with antibodies because of their low non-specific adsorption on the Au/CD44 surface. Prior to conjugation, the surface binding capacity (Bmax) and equilibrium dissociation constant (KD) of the specific antibodies against CD44 (anti-CD44) were found to be 263.32 ± 2.44 m° and 1.00 × 10−7 ± 2.29 × 10−9 M, respectively. QDs-NH2 and anti-CD44 were conjugated at their initial molar ratios of 1:3, 1:5, 1:10 and 1:12. SPR measurements showed that the conjugates (QDs-anti-CD44) prepared using 1:10 and 1:12 molar ratios interacted comparably with immobilized CD44 biomarkers. The equilibrium angles in the case of 10- and 12-fold concentrations of anti-CD44 were calculated to be 60.43 ± 4.51 and 61.36 ± 4.40 m°, respectively. This could be explained by the QDs-NH2 and anti-CD44 having a similar surface loading (about four molecules per QDs-NH2) and similar hydrodynamic diameters, which were 46.63 ± 3.86 and 42.42 ± 0.80 nm for the 1:10 and 1:12 ratios, respectively. An initial QDs-NH2: anti-CD44 molar ratio of 1:10 was chosen as being optimal. SPR spectroscopy proved to be the right choice for QDs-anti-CD44 conjugation optimization, and can be used for the evaluation of conjugation efficiency for other nanostructures with various bio-recognition molecules.
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Affiliation(s)
- Anton Popov
- Department of Immunology, State Research Institute Centre for Innovative Medicine, Santariskiu Str. 5, LT-08406 Vilnius, Lithuania
- NanoTechnas—Center of Nanotechnology and Materials Science, Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania
- Correspondence: (A.P.); (A.R.)
| | - Viktorija Lisyte
- NanoTechnas—Center of Nanotechnology and Materials Science, Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania
| | - Asta Kausaite-Minkstimiene
- Department of Immunology, State Research Institute Centre for Innovative Medicine, Santariskiu Str. 5, LT-08406 Vilnius, Lithuania
- NanoTechnas—Center of Nanotechnology and Materials Science, Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania
| | - Eiva Bernotiene
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, Santariskiu Str. 5, LT-08406 Vilnius, Lithuania
- Department of Chemistry and Bioengineering, The Faculty of Fundamental Sciences, Vilnius Gediminas Technical University, Vilnius-Tech, LT-10223 Vilnius, Lithuania
| | - Almira Ramanaviciene
- Department of Immunology, State Research Institute Centre for Innovative Medicine, Santariskiu Str. 5, LT-08406 Vilnius, Lithuania
- NanoTechnas—Center of Nanotechnology and Materials Science, Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania
- Correspondence: (A.P.); (A.R.)
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Wu CC, Chiang YH, Chiang HY. A Label-Free Electrochemical Impedimetric Immunosensor with Biotinylated-Antibody for SARS-CoV-2 Nucleoprotein Detection in Saliva. BIOSENSORS 2022; 12:bios12050265. [PMID: 35624566 PMCID: PMC9138907 DOI: 10.3390/bios12050265] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/16/2022] [Accepted: 04/20/2022] [Indexed: 05/05/2023]
Abstract
The timely detecting of SARS-CoV-2 coronavirus antigens for infection validation is an urgent request for COVID-19 pandemic control. This study constructed label-free electrochemical impedance spectroscopy (EIS)-based immunosensors based on gold nanostructured screen-printed carbon electrodes (AuNS/SPCEs) to detect the SARS-CoV-2 nucleocapsid protein (N-protein) in saliva. Using short-chain 3-mercaptopropionic acid (MPA) as a linker to covalently bond streptavidin (SA) and bovine serum albumin (BSA) for controlling the oriented immobilization of the biotinylated anti-N-protein antibody (BioAb) can offer a greater sensitivity, a lower limit of detection (LOD), and better reproducibility of immunosensors (defined as BioAb/SA-BSA/MPA/AuNS/SPCEs) than the antibody randomly immobilized immunosensors and the long-chain 11-mercaptoundecanoic acid (MUA)-modified immunosensors (BioAb/SA-BSA/MUA/AuNS/SPCEs). The BioAb/SA-BSA/MPA/AuNS/SPCE-based immunosensors presented good linearity from 0.01 ng/mL to 100 ng/mL and a low LOD of 6 pg/mL in a phosphate buffer solution (PBS) and PBS-diluted saliva. Moreover, the immunosensor exhibited little cross-activity with other viral antigens such as MERS-CoV N-protein, influenza A N-protein, influenza B N-protein, and SARS-CoV-2 spike protein, indicating the high specificity of the immunosensors. The disposable label-free EIS-based immunosensors have promising potential in facilitating the rapid and sensitive tests of saliva-based COVID-19 diagnostics.
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Affiliation(s)
- Ching-Chou Wu
- Department of Bio-industrial Mechatronics Engineering, National Chung Hsing University, Taichung 402, Taiwan;
- Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung 402, Taiwan
- Correspondence: ; Tel.: +886-4-2285-1268
| | - Yu-Huan Chiang
- Department of Bio-industrial Mechatronics Engineering, National Chung Hsing University, Taichung 402, Taiwan;
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Ruiz G, Tripathi K, Okyem S, Driskell JD. pH Impacts the Orientation of Antibody Adsorbed onto Gold Nanoparticles. Bioconjug Chem 2019; 30:1182-1191. [DOI: 10.1021/acs.bioconjchem.9b00123] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Guadalupe Ruiz
- Department of Chemistry, Illinois State University, Normal, Illinois 61790, United States
| | - Kiran Tripathi
- Department of Chemistry, Illinois State University, Normal, Illinois 61790, United States
| | - Samuel Okyem
- Department of Chemistry, Illinois State University, Normal, Illinois 61790, United States
| | - Jeremy D. Driskell
- Department of Chemistry, Illinois State University, Normal, Illinois 61790, United States
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8
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Awsiuk K, Petrou P, Thanassoulas A, Raczkowska J. Orientation of Biotin-Binding Sites in Streptavidin Adsorbed onto the Surface of Polythiophene Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3058-3066. [PMID: 30696244 DOI: 10.1021/acs.langmuir.8b03509] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The orientation of biotin-binding sites of streptavidin adsorbed to thin films of three polythiophenes (PTs), namely, regioregular poly(3-hexylthiophene) (RP3HT), regiorandom poly(3-butylthiophene) (P3BT), and poly(3,3‴-didodecylquaterthiophene) (PQT12), has been investigated. Polymer films were examined prior to and after protein adsorption with atomic force microscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Principal component analysis (PCA) applied to ToF-SIMS data revealed subtle changes in surface chemistry of polymer films and orientation of adsorbed streptavidin. PCA resolved the surface alignment of alkyl side chains and differentiated the ToF-SIMS data for PQT12, RP3HT, and P3BT, verifying an amorphous morphology for P3BT and a semicrystalline one for PQT12 and RP3HT. After the characterization of the polymeric films, streptavidin adsorption from solutions with different protein concentrations (up to 300 μg/mL) has been conducted. The PCA results distinguished between amino acids characteristic for external regions of streptavidin molecules adsorbed to different PTs suggest that streptavidin adsorbed to PQT12 exposes molecular regions rich in tryptophan and tyrosine, which are components of the biotin-binding sites. The latter results were confirmed using biotin-labeled horse radish peroxidase to estimate the exposed binding sites of streptavidin adsorbed onto the different PT films. The analysis of streptavidin structure suggests that interaction between polythiophene film and dipole moment of streptavidin subunit is responsible for orientation of biotin-binding sites.
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Affiliation(s)
- Kamil Awsiuk
- M. Smoluchowski Institute of Physics , Jagiellonian University , Łojasiewicza 11 , 30-348 Kraków , Poland
- Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety , NCSR Demokritos , 15310 Agia Paraskevi , Greece
| | - Panagiota Petrou
- Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety , NCSR Demokritos , 15310 Agia Paraskevi , Greece
| | - Angelos Thanassoulas
- Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety , NCSR Demokritos , 15310 Agia Paraskevi , Greece
| | - Joanna Raczkowska
- M. Smoluchowski Institute of Physics , Jagiellonian University , Łojasiewicza 11 , 30-348 Kraków , Poland
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Feng C, Liu Y, Ren CL. Temperature-regulated protein adsorption on a PNIPAm layer. SOFT MATTER 2018; 14:6521-6529. [PMID: 30051118 DOI: 10.1039/c8sm01024b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In immunosensors, antibody orientation is a key factor that determines the sensitivity of a device. To date much effort has been devoted to exploring strategies for the direct control of the orientation of antibodies immobilized on a bioactive surface, but less attention has been paid to controlling the orientation of intermediate proteins (though usually used when immobilizing antibodies), which may greatly limit the sensitivity of immunological activities. Therefore, it is of great significance to seek novel methods for controlling protein orientation. Here, we design a new strategy for controlling protein orientation. The main idea is to bind proteins to a ligand-functionalized poly(N-isopropylacrylamide) (PNIPAm) layer, and then the protein orientation can be mediated by environmental temperature. The theory predicts that the protein orientation can show unexpected triple-thermo-responsive behavior. Based on the fraction of ligand adsorbed by the protein, the reponsive behavior can be either complete adsorption or partial adsorption, which is determind by the polymer's surface coverage and the protein's properties. We expect that the present strategy can enrich the methods for controlling intermediate protein orientation and can guide the design of novel immunosensors with superior sensitivity.
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Affiliation(s)
- Chao Feng
- State Key Laboratory of Metastable Materials Science & Technology and Hebei Key Laboratory of Microstructural Material Physics, School of Science, Yanshan University, Qinhuangdao, 066004, China.
| | - Yong Liu
- State Key Laboratory of Metastable Materials Science & Technology and Hebei Key Laboratory of Microstructural Material Physics, School of Science, Yanshan University, Qinhuangdao, 066004, China.
| | - Chun-Lai Ren
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, 210093, China. and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
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Tripathi K, Driskell JD. Quantifying Bound and Active Antibodies Conjugated to Gold Nanoparticles: A Comprehensive and Robust Approach To Evaluate Immobilization Chemistry. ACS OMEGA 2018; 3:8253-8259. [PMID: 30087938 PMCID: PMC6072236 DOI: 10.1021/acsomega.8b00591] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 07/12/2018] [Indexed: 05/10/2023]
Abstract
Gold nanoparticles (AuNPs) functionalized with antibodies have the potential to improve biosensing technology because of the unique optical properties of AuNPs and the specificity of antibody-antigen interactions. Critical to the development and optimization of these AuNP-enabled sensing technologies is the immobilization of the antibody onto the AuNP. The development of novel immobilization strategies that optimize antibody loading and orientation in an effort to enhance antibody activity, and therefore assay performance, has been the focus of many recent studies. However, few analytical methods exist to accurately quantify the activity of conjugated antibodies and reliably compare different immobilization strategies. Herein, we describe an enzyme-mediated assay to quantify the fraction of the immobilized antibodies that is accessible for antigen binding. Anti-horseradish peroxidase (anti-HRP) antibody is mixed with AuNPs to allow for conjugation, and the unbound, excess antibody is quantified with a modified Bradford assay to determine antibody loading onto AuNPs. The conjugates are then mixed with excess HRP to saturate all accessible binding sites, and bound HRP is quantified based on enzymatic reaction rate. This analytical scheme was used to compare two common immobilization strategies, nonspecific adsorption and protein A-mediated immobilization. We found that the antibody surface coverage is greater for direct adsorption than protein A-mediated binding; however, 23 ± 6% of the directly adsorbed antibodies were active, whereas 91 ± 19% of the antibodies bound through protein A were active. In addition to establishing this method as quantitatively precise and accurate, our results emphasize the need to quantify both antibody loading and antibody activity upon conjugation to gain greater insight into differences in immobilization chemistries and identify optimum protein conjugation strategies to maximize immunoassay performance.
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Zhang S, Geryak R, Geldmeier J, Kim S, Tsukruk VV. Synthesis, Assembly, and Applications of Hybrid Nanostructures for Biosensing. Chem Rev 2017; 117:12942-13038. [DOI: 10.1021/acs.chemrev.7b00088] [Citation(s) in RCA: 206] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Shuaidi Zhang
- School of Materials Science
and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, United States
| | - Ren Geryak
- School of Materials Science
and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, United States
| | - Jeffrey Geldmeier
- School of Materials Science
and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, United States
| | - Sunghan Kim
- School of Materials Science
and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, United States
| | - Vladimir V. Tsukruk
- School of Materials Science
and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, United States
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12
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Surface immobilized antibody orientation determined using ToF-SIMS and multivariate analysis. Acta Biomater 2017; 55:172-182. [PMID: 28359858 DOI: 10.1016/j.actbio.2017.03.038] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 03/21/2017] [Accepted: 03/24/2017] [Indexed: 01/06/2023]
Abstract
Antibody orientation at solid phase interfaces plays a critical role in the sensitive detection of biomolecules during immunoassays. Correctly oriented antibodies with solution-facing antigen binding regions have improved antigen capture as compared to their randomly oriented counterparts. Direct characterization of oriented proteins with surface analysis methods still remains a challenge however surface sensitive techniques such as Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) provide information-rich data that can be used to probe antibody orientation. Diethylene glycol dimethyl ether plasma polymers (DGpp) functionalized with chromium (DGpp+Cr) have improved immunoassay performance that is indicative of preferential antibody orientation. Herein, ToF-SIMS data from proteolytic fragments of anti-EGFR antibody bound to DGpp and DGpp+Cr are used to construct artificial neural network (ANN) and principal component analysis (PCA) models indicative of correctly oriented systems. Whole antibody samples (IgG) test against each of the models indicated preferential antibody orientation on DGpp+Cr. Cross-reference between ANN and PCA models yield 20 mass fragments associated with F(ab')2 region representing correct orientation, and 23 mass fragments associated with the Fc region representing incorrect orientation. Mass fragments were then compared to amino acid fragments and amino acid composition in F(ab')2 and Fc regions. A ratio of the sum of the ToF-SIMS ion intensities from the F(ab')2 fragments to the Fc fragments demonstrated a 50% increase in intensity for IgG on DGpp+Cr as compared to DGpp. The systematic data analysis methodology employed herein offers a new approach for the investigation of antibody orientation applicable to a range of substrates. STATEMENT OF SIGNIFICANCE Controlled orientation of antibodies at solid phases is critical for maximizing antigen detection in biosensors and immunoassays. Surface-sensitive techniques (such as ToF-SIMS), capable of direct characterization of surface immobilized and oriented antibodies, are under-utilized in current practice. Selection of a small number of mass fragments for analysis, typically pertaining to amino acids, is commonplace in literature, leaving the majority of the information-rich spectra unanalyzed. The novelty of this work is the utilization of a comprehensive, unbiased mass fragment list and the employment of principal component analysis (PCA) and artificial neural network (ANN) models in a unique methodology to prove antibody orientation. This methodology is of significant and broad interest to the scientific community as it is applicable to a range of substrates and allows for direct, label-free characterization of surface bound proteins.
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13
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Orientation and characterization of immobilized antibodies for improved immunoassays (Review). Biointerphases 2017; 12:02D301. [DOI: 10.1116/1.4978435] [Citation(s) in RCA: 202] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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14
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Shen M, Rusling J, Dixit CK. Site-selective orientated immobilization of antibodies and conjugates for immunodiagnostics development. Methods 2017; 116:95-111. [PMID: 27876681 PMCID: PMC5374010 DOI: 10.1016/j.ymeth.2016.11.010] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/16/2016] [Accepted: 11/17/2016] [Indexed: 01/11/2023] Open
Abstract
Immobilized antibody systems are the key to develop efficient diagnostics and separations tools. In the last decade, developments in the field of biomolecular engineering and crosslinker chemistry have greatly influenced the development of this field. With all these new approaches at our disposal, several new immobilization methods have been created to address the main challenges associated with immobilized antibodies. Few of these challenges that we have discussed in this review are mainly associated to the site-specific immobilization, appropriate orientation, and activity retention. We have discussed the effect of antibody immobilization approaches on the parameters on the performance of an immunoassay.
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Affiliation(s)
- Min Shen
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060
| | - James Rusling
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060
- Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269-3136
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut 060
- School of Chemistry, National University of Ireland at Galway, Galway, Ireland
| | - Chandra K Dixit
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060
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15
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Scaffolds for oriented and close-packed immobilization of immunoglobulins. Biosens Bioelectron 2017; 89:810-821. [DOI: 10.1016/j.bios.2016.10.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/27/2016] [Accepted: 10/03/2016] [Indexed: 02/07/2023]
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16
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Welch NG, Madiona RMT, Scoble JA, Muir BW, Pigram PJ. ToF-SIMS and Principal Component Analysis Investigation of Denatured, Surface-Adsorbed Antibodies. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10824-10834. [PMID: 27715065 DOI: 10.1021/acs.langmuir.6b02754] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Antibody denaturation at solid-liquid interfaces plays an important role in the sensitivity of protein assays such as enzyme-linked immunosorbent assays (ELISAs). Surface immobilized antibodies must maintain their native state, with their antigen binding (Fab) region intact, to capture antigens from biological samples and permit disease detection. In this work, two identical sample sets were prepared with whole antibody IgG, F(ab')2 and Fc fragments, immobilized to either a silicon wafer or a diethylene glycol dimethyl ether plasma polymer surface. Analysis was conducted on one sample set at day 0, and the second sample set after 14 days in vacuum, with time-of-flight secondary ion mass spectrometry (ToF-SIMS) for molecular species representative of denaturation. A 1003 mass fragment peak list was compiled from ToF-SIMS data and compared to a 35 amino acid mass fragment peak list using principal component analysis. Several ToF-SIMS secondary ions, pertaining to disulfide and thiol species, were identified in the 14 day (presumably denatured) samples. A substrate and primary ion independent marker for denaturation (aging) was then produced using a ratio of mass peak intensities according to denaturation ratio: [I61.9534 + I62.9846 + I122.9547 + I84.9609 + I120.9461]/[I30.9979 + I42.9991 + I73.0660 + I147.0780]. The ratio successfully identifies denaturation on both the silicon and plasma polymer substrates and for spectra generated with Mn+, Bi+, and Bi3+ primary ions. We believe this ratio could be employed to as a marker of denaturation of antibodies on a plethora of substrates.
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Affiliation(s)
- Nicholas G Welch
- Centre for Materials and Surface Science and Department of Chemistry and Physics, School of Molecular Sciences, La Trobe University , Melbourne, VIC 3086, Australia
- CSIRO Manufacturing , Clayton, VIC 3168, Australia
| | - Robert M T Madiona
- Centre for Materials and Surface Science and Department of Chemistry and Physics, School of Molecular Sciences, La Trobe University , Melbourne, VIC 3086, Australia
- CSIRO Manufacturing , Clayton, VIC 3168, Australia
| | | | | | - Paul J Pigram
- Centre for Materials and Surface Science and Department of Chemistry and Physics, School of Molecular Sciences, La Trobe University , Melbourne, VIC 3086, Australia
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17
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Funari R, Della Ventura B, Altucci C, Offenhäusser A, Mayer D, Velotta R. Single Molecule Characterization of UV-Activated Antibodies on Gold by Atomic Force Microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:8084-91. [PMID: 27444884 DOI: 10.1021/acs.langmuir.6b02218] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The interaction between proteins and solid surfaces can influence their conformation and therefore also their activity and affinity. These interactions are highly specific for the respective combination of proteins and solids. Consequently, it is desirable to investigate the conformation of proteins on technical surfaces, ideally at single molecule level, and to correlate the results with their activity. This is in particular true for biosensors where the conformation-dependent target affinity of an immobilized receptor determines the sensitivity of the sensor. Here, we investigate for the first time the immobilization and orientation of antibodies (Abs) photoactivated by a photonic immobilization technique (PIT), which has previously demonstrated to enhance binding capabilities of antibody receptors. The photoactivated immunoglobulins are immobilized on ultrasmooth template stripped gold films and investigated by atomic force microscopy (AFM) at the level of individual molecules. The observed protein orientations are compared with results of nonactivated antibodies adsorbed on similar gold films and mica reference samples. We find that the behavior of Abs is similar for mica and gold when the protein are not treated (physisorption), whereas smaller contact area and larger heights are measured when Abs are treated (PIT). This is explained by assuming that the activated antibodies tend to be more upright compared with nonirradiated ones, thereby providing a better exposure of the binding sites. This finding matches the observed enhancement of Abs binding efficiency when PIT is used to functionalize gold surface of QCM-based biosensors.
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Affiliation(s)
- R Funari
- Department of Physics Ettore Pancini, Università di Napoli Federico II , via Cintia, I-80126 Napoli, Italy
| | - B Della Ventura
- Department of Physics Ettore Pancini, Università di Napoli Federico II , via Cintia, I-80126 Napoli, Italy
| | - C Altucci
- Department of Physics Ettore Pancini, Università di Napoli Federico II , via Cintia, I-80126 Napoli, Italy
| | - A Offenhäusser
- Peter Grünberg Institute (PGI-8) and Institute of Complex Systems (ICS-8), Forschungszentrum Jülich GmbH , 52428 Jülich, Germany
| | - D Mayer
- Peter Grünberg Institute (PGI-8) and Institute of Complex Systems (ICS-8), Forschungszentrum Jülich GmbH , 52428 Jülich, Germany
| | - R Velotta
- Department of Physics Ettore Pancini, Università di Napoli Federico II , via Cintia, I-80126 Napoli, Italy
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18
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Crivianu-Gaita V, Thompson M. Immobilization of Fab’ fragments onto substrate surfaces: A survey of methods and applications. Biosens Bioelectron 2015; 70:167-80. [DOI: 10.1016/j.bios.2015.03.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 03/10/2015] [Accepted: 03/16/2015] [Indexed: 10/23/2022]
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19
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Hosseinidoust Z, Olsson AL, Tufenkji N. Going viral: Designing bioactive surfaces with bacteriophage. Colloids Surf B Biointerfaces 2014; 124:2-16. [DOI: 10.1016/j.colsurfb.2014.05.036] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 05/25/2014] [Accepted: 05/26/2014] [Indexed: 12/22/2022]
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20
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Tsai CW, Jheng SL, Chen WY, Ruaan RC. Strategy of Fc-Recognizable Peptide Ligand Design for Oriented Immobilization of Antibody. Anal Chem 2014; 86:2931-8. [DOI: 10.1021/ac4029467] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Ching-Wei Tsai
- Department
of Chemical and Materials Engineering, National Central University, Chung-Li City, Taoyuan 32001, Taiwan
| | - Siang-Long Jheng
- Department
of Chemical and Materials Engineering, National Central University, Chung-Li City, Taoyuan 32001, Taiwan
| | - Wen-Yih Chen
- Department
of Chemical and Materials Engineering, National Central University, Chung-Li City, Taoyuan 32001, Taiwan
- Institute
of Biomedical Engineering, National Central University, Chung-Li City, Taoyuan 32001, Taiwan
| | - Ruoh-Chyu Ruaan
- Department
of Chemical and Materials Engineering, National Central University, Chung-Li City, Taoyuan 32001, Taiwan
- Institute
of Biomedical Engineering, National Central University, Chung-Li City, Taoyuan 32001, Taiwan
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21
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Awsiuk K, Budkowski A, Psarouli A, Petrou P, Bernasik A, Kakabakos S, Rysz J, Raptis I. Protein adsorption and covalent bonding to silicon nitride surfaces modified with organo-silanes: Comparison using AFM, angle-resolved XPS and multivariate ToF-SIMS analysis. Colloids Surf B Biointerfaces 2013; 110:217-24. [DOI: 10.1016/j.colsurfb.2013.04.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 04/15/2013] [Accepted: 04/17/2013] [Indexed: 01/08/2023]
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22
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Trilling AK, Harmsen MM, Ruigrok VJ, Zuilhof H, Beekwilder J. The effect of uniform capture molecule orientation on biosensor sensitivity: Dependence on analyte properties. Biosens Bioelectron 2013; 40:219-26. [DOI: 10.1016/j.bios.2012.07.027] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 06/28/2012] [Accepted: 07/13/2012] [Indexed: 01/25/2023]
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23
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Trilling AK, Beekwilder J, Zuilhof H. Antibody orientation on biosensor surfaces: a minireview. Analyst 2013; 138:1619-27. [DOI: 10.1039/c2an36787d] [Citation(s) in RCA: 301] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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