A new issue of this journal has just been published. To see abstracts of the papers it contains (with links through to the full papers) click here:
Selected papers from the latest issue:
An Enzymatic Immunoassay Microfluidics Integrated with Membrane Valves for Microsphere Retention and Reagent Mixing
25 February 2012, 21:52:54
Publication year: 2012
Source: Biosensors and Bioelectronics, Available online 25 February 2012
Li Ren, Jian-Chun Wang, Wenming Liu, Qin Tu, Rui Liu, ...
The present study presents a new microfluidic device integrated with pneumatic microvalves and a membrane mixer for enzyme-based immunoassay of acute myocardial infarction biomarkers, namely, myoglobin, and heart-type fatty acid binding protein (H-FABP). Superparamagnetic microspheres with carboxyl groups on their surfaces were used as antibody solid carriers. A membrane mixer consisting of four ψ-type membrane valves was assembled under the reaction chamber for on-chip performing microsphere trapping and reagent mixing. The entire immunoassay process, including microsphere capture, reagent input, mixing, and subsequent reaction, was accomplished on the device either automatically or manually. The post-reaction substrate resultant was analyzed using a microplate reader. The results show that the average absorbance value is correlated with the concentration of cardiac markers, in agreement with the results obtained using a conventional microsphere-based immunoassay; this indicated that the proposed on-chip immunoassay protocol could be used to detect both myoglobin and H-FABP. The minimum detectable concentration is 5 ng/mL for myoglobin and 1 ng/mL for H-FABP.
Source: Biosensors and Bioelectronics, Available online 25 February 2012
Li Ren, Jian-Chun Wang, Wenming Liu, Qin Tu, Rui Liu, ...
The present study presents a new microfluidic device integrated with pneumatic microvalves and a membrane mixer for enzyme-based immunoassay of acute myocardial infarction biomarkers, namely, myoglobin, and heart-type fatty acid binding protein (H-FABP). Superparamagnetic microspheres with carboxyl groups on their surfaces were used as antibody solid carriers. A membrane mixer consisting of four ψ-type membrane valves was assembled under the reaction chamber for on-chip performing microsphere trapping and reagent mixing. The entire immunoassay process, including microsphere capture, reagent input, mixing, and subsequent reaction, was accomplished on the device either automatically or manually. The post-reaction substrate resultant was analyzed using a microplate reader. The results show that the average absorbance value is correlated with the concentration of cardiac markers, in agreement with the results obtained using a conventional microsphere-based immunoassay; this indicated that the proposed on-chip immunoassay protocol could be used to detect both myoglobin and H-FABP. The minimum detectable concentration is 5 ng/mL for myoglobin and 1 ng/mL for H-FABP.
Highlights
► A new and integrated microfluidics for microsphere-based enzymatic immunoassay was described. ► Microsphere retention and reagent mixing were realized via membrane microvalves and a mixer. ► The entire immunoassay process could be accomplished either automatically or manually. ► Two acute myocardial infarction-related early biomarkers were analyzed as case studies.Label-free reflectometric interference microchip biosensor based on nanoporous alumina for detection of circulating tumour cells
25 February 2012, 21:52:54
Publication year: 2012
Source: Biosensors and Bioelectronics, Available online 25 February 2012
Tushar Kumeria, Mahaveer D. Kurkuri, Kerrilyn R. Diener, Luke Parkinson, Dusan Losic
In this report, a label-free reflectometric interference spectroscopy (RIfS) based microchip biosensor for the detection of circulating tumour cells (CTCs) is demonstrated. Highly ordered nanoporous anodic aluminium oxide (AAO) fabricated by electrochemical anodization of aluminium foil was used as the RIfS sensing platform. Biotinylated anti-EpCAM antibody that specifically binds to human cancer cells of epithelial origin such as pancreatic cancer cells (PANC-1) was covalently attached to the AAO surface through multiple surface functionalization steps. Whole blood or phosphate buffer saline spiked with low numbers of pancreatic cancer cells were successfully detected by specially designed microfluidic device incorporating an AAO RIfS sensor, without labour intensive fluorescence labelling and/or pre-enhancement process. Our results show that the developed device is capable of selectively detecting of cancer cells, within a concentrations range of 1,000 to 100,000 cells/mL, with a detection limit of < 1000 cells/mL, a response time of <5 minutes and sample volume of 50 μL of. The presented RIfS method shows considerable promise for translation to a rapid and cost-effective point-of-care diagnostic device for the detection of CTCs in patients with metastatic cancer.
Source: Biosensors and Bioelectronics, Available online 25 February 2012
Tushar Kumeria, Mahaveer D. Kurkuri, Kerrilyn R. Diener, Luke Parkinson, Dusan Losic
In this report, a label-free reflectometric interference spectroscopy (RIfS) based microchip biosensor for the detection of circulating tumour cells (CTCs) is demonstrated. Highly ordered nanoporous anodic aluminium oxide (AAO) fabricated by electrochemical anodization of aluminium foil was used as the RIfS sensing platform. Biotinylated anti-EpCAM antibody that specifically binds to human cancer cells of epithelial origin such as pancreatic cancer cells (PANC-1) was covalently attached to the AAO surface through multiple surface functionalization steps. Whole blood or phosphate buffer saline spiked with low numbers of pancreatic cancer cells were successfully detected by specially designed microfluidic device incorporating an AAO RIfS sensor, without labour intensive fluorescence labelling and/or pre-enhancement process. Our results show that the developed device is capable of selectively detecting of cancer cells, within a concentrations range of 1,000 to 100,000 cells/mL, with a detection limit of < 1000 cells/mL, a response time of <5 minutes and sample volume of 50 μL of. The presented RIfS method shows considerable promise for translation to a rapid and cost-effective point-of-care diagnostic device for the detection of CTCs in patients with metastatic cancer.
Highlights
► We develop a label-free reflectometric interference spectroscopy (RIfS) microchip biosensor for the detection of circulating tumour cells (CTCs) ► A nanoporous alumina functionlized with biotinylated human anti-EpCAM antibodies is used as a sensing platform ► The measurement of CTCs with concentrations of 1,000 to 200,000 cells/mL in buffer and whole blood is demonstrated. ► The device is highly selective to CTCs, has response time of <5 minutes and requires less than 50 μL of sample.TiO2/MWNTs Nanocomposites-Based Electrochemical Strategy for Label-Free Assay of Casein Kinase II Activity and Inhibition
25 February 2012, 21:52:54
Publication year: 2012
Source: Biosensors and Bioelectronics, Available online 25 February 2012
Xiaoxiao He, Zhifeng Chen, Yonghong Wang, Kemin Wang, Jing Su, ...
In this paper, a novel label-free electrochemical strategy has been developed for assay of casein kinase II (CK2) activity and inhibition using TiO2/MWNTs nanocomposites. This detection system takes advantage of specific binding of the phosphate groups with TiO2nanoparticles and fast electron transfer rate of MWNTs. In this strategy, the synthesized TiO2/MWNTs nanocomposite was firstly deposited on the surface of a glassy carbon electrode (GCE). The presence of MWNTs not only increased the surface area of the electrode but also promoted electron-transfer reaction. In the presence of CK2, the kinase reaction resulted in the phosphorylation of peptide substrates. The phosphorylated peptides were subsequently captured to the surface of GCE modified with TiO2/MWNTs nanocomposite through specific binding of the phosphate groups with TiO2nanoparticles. Then the access of redox probe [Fe(CN)6]to electrode surface was blocked. As a result, the decrease peak currents were related to the concentrations of the CK2, providing a sensing mechanism for monitoring peptides phosphorylation. The electrochemical strategy can be employed to assay CK2 activity with a low detection limit of 0.07 U/mL. The linear range of the assay for CK2 was 0 U/mL to 0.5 U/mL. Furthermore, the interferences experiments of PKA and inhibition of CK2 have been also studied by using this strategy.
Source: Biosensors and Bioelectronics, Available online 25 February 2012
Xiaoxiao He, Zhifeng Chen, Yonghong Wang, Kemin Wang, Jing Su, ...
In this paper, a novel label-free electrochemical strategy has been developed for assay of casein kinase II (CK2) activity and inhibition using TiO2/MWNTs nanocomposites. This detection system takes advantage of specific binding of the phosphate groups with TiO2nanoparticles and fast electron transfer rate of MWNTs. In this strategy, the synthesized TiO2/MWNTs nanocomposite was firstly deposited on the surface of a glassy carbon electrode (GCE). The presence of MWNTs not only increased the surface area of the electrode but also promoted electron-transfer reaction. In the presence of CK2, the kinase reaction resulted in the phosphorylation of peptide substrates. The phosphorylated peptides were subsequently captured to the surface of GCE modified with TiO2/MWNTs nanocomposite through specific binding of the phosphate groups with TiO2nanoparticles. Then the access of redox probe [Fe(CN)6]to electrode surface was blocked. As a result, the decrease peak currents were related to the concentrations of the CK2, providing a sensing mechanism for monitoring peptides phosphorylation. The electrochemical strategy can be employed to assay CK2 activity with a low detection limit of 0.07 U/mL. The linear range of the assay for CK2 was 0 U/mL to 0.5 U/mL. Furthermore, the interferences experiments of PKA and inhibition of CK2 have been also studied by using this strategy.
Highlights
► We develop a label-free electrochemical strategy for assay of CK2 and inhibition. ► The electrochemical assay is based on TiO2/MWNTs nanocomposites. ► Specific binding of the phosphate groups with TiO2nanoparticles. ► Fast electron transfer rate of MWNTs. ► Providing a general platform for monitoring the activity of other kinases.A novel approach to determining the affinity of protein-carbohydrate interactions employing adherent cancer cells grown on a biosensor surface
25 February 2012, 21:52:54
Publication year: 2012
Source: Biosensors and Bioelectronics, Available online 25 February 2012
Diluka Peiris, Anatoliy Markiv, G. Paul Curley, Miriam V. Dwek
The development of biological agents for the treatment of solid tumours is an area of considerable activity. We are pursuing carbohydrate-binding proteins (lectins) in a strategy aimed at targeting cancer-associated changes in glycosylation. To evaluate lectin-cancer cell interactions we developed a novel cell biosensor in which binding events take place at the cell surface, more closely mimicking anin vivosystem. Metastatic, SW620, and non-metastatic, SW480, colorectal cancer cells were grown on the surface of a tissue-culture compatible polystyrene coated biosensor chip and housed in a quartz crystal microbalance (QCM) apparatus, the kinetics of binding of a diverse range of lectins was evaluated. The lectinHelix pomatiaagglutinin (HPA) has been shown to bind aggressive metastatic cancer and was produced in recombinant form (His- and RFP-tagged). The affinity of HPA was in the nanomolar range to the metastatic SW620 cells but was only in the micromolar range to the non-metastatic SW480. Overall, the dissociation constant (KD) of the lectins tested in the new cell biosensor system was an order of magnitude lower (nanomolar range) than has generally been reported with systems such as QCM/SPR. This new cell-biosensor enables molecular interactions to be studied in a more relevant environment. An intrinsic problem with developing new biological therapies is the difficulty in determining the affinity with which proteins will interact with intact cell surfaces. This methodology will be of interest to researchers developing new biological approaches for targeting cell surfaces in a wide range of diseases, including cancer.
Source: Biosensors and Bioelectronics, Available online 25 February 2012
Diluka Peiris, Anatoliy Markiv, G. Paul Curley, Miriam V. Dwek
The development of biological agents for the treatment of solid tumours is an area of considerable activity. We are pursuing carbohydrate-binding proteins (lectins) in a strategy aimed at targeting cancer-associated changes in glycosylation. To evaluate lectin-cancer cell interactions we developed a novel cell biosensor in which binding events take place at the cell surface, more closely mimicking anin vivosystem. Metastatic, SW620, and non-metastatic, SW480, colorectal cancer cells were grown on the surface of a tissue-culture compatible polystyrene coated biosensor chip and housed in a quartz crystal microbalance (QCM) apparatus, the kinetics of binding of a diverse range of lectins was evaluated. The lectinHelix pomatiaagglutinin (HPA) has been shown to bind aggressive metastatic cancer and was produced in recombinant form (His- and RFP-tagged). The affinity of HPA was in the nanomolar range to the metastatic SW620 cells but was only in the micromolar range to the non-metastatic SW480. Overall, the dissociation constant (KD) of the lectins tested in the new cell biosensor system was an order of magnitude lower (nanomolar range) than has generally been reported with systems such as QCM/SPR. This new cell-biosensor enables molecular interactions to be studied in a more relevant environment. An intrinsic problem with developing new biological therapies is the difficulty in determining the affinity with which proteins will interact with intact cell surfaces. This methodology will be of interest to researchers developing new biological approaches for targeting cell surfaces in a wide range of diseases, including cancer.
Highlights
► A novel system in which cells are grown on a biosensor chip is described. ► Affinity measurements are made directly at the cell surface. ► The sensor surface is regenerated and can be used for up to 30 experiments. ► A new method for testing novel biological reagents that target the cell surface.A study of electrochemical biosensor for analysis of three-dimensional (3D) cell culture
25 February 2012, 21:52:54
Publication year: 2012
Source: Biosensors and Bioelectronics, Available online 25 February 2012
Se Hoon Jeong, Dong Woo Lee, Sanghyo Kim, Jhingook Kim, Bosung Ku
Cell culture has a fundamental role not only in regenerative medicine but also in biotechnology, pharmacology, impacting both drug discovery and manufacturing. Although cell culture has been generally developed for only two-dimensional (2D) culture systems, three-dimensional (3D) culture is being spotlighted as the means to mimic in vivo cellular conditions. In this study, a method for cytotoxicity assay using an electrochemical biosensor applying 3D cell culture is presented. In order to strengthen the advantage of a 3D cell culture, the experimental condition of gelation between several types of sol-gels (alginate, collagen, matrigel) and cancer cells can be optimized to make a 3D cell structure on the electrode, which will show the reproducibility of electrical measurement for long-term monitoring. Moreover, cytotoxicity test results applying this method showed IC50value of A549 lung cancer cells to erlotinib. Thus, this study evaluates the feasibility of application of the electrochemical biosensor for 3D cell culture to cytotoxicity assay for investigation of 3D cell response to drug compounds.
Source: Biosensors and Bioelectronics, Available online 25 February 2012
Se Hoon Jeong, Dong Woo Lee, Sanghyo Kim, Jhingook Kim, Bosung Ku
Cell culture has a fundamental role not only in regenerative medicine but also in biotechnology, pharmacology, impacting both drug discovery and manufacturing. Although cell culture has been generally developed for only two-dimensional (2D) culture systems, three-dimensional (3D) culture is being spotlighted as the means to mimic in vivo cellular conditions. In this study, a method for cytotoxicity assay using an electrochemical biosensor applying 3D cell culture is presented. In order to strengthen the advantage of a 3D cell culture, the experimental condition of gelation between several types of sol-gels (alginate, collagen, matrigel) and cancer cells can be optimized to make a 3D cell structure on the electrode, which will show the reproducibility of electrical measurement for long-term monitoring. Moreover, cytotoxicity test results applying this method showed IC50value of A549 lung cancer cells to erlotinib. Thus, this study evaluates the feasibility of application of the electrochemical biosensor for 3D cell culture to cytotoxicity assay for investigation of 3D cell response to drug compounds.
No comments:
Post a Comment