The copper binding properties of metformin – QCM-D, XPS and nanobead agglomeration

Quan, Xueling; Uddin, Rokon; Heiskanen, Arto; Parmvi, Mattias; Donolato, Marco; Hansen, Mikkel Fougt; Rena, Graham; Boisen, Anja

doi:10.1039/c5cc04321b

Cited by 21 publications

(23 citation statements)

References 36 publications

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“…Binding energies of around 400 eV were reported by Lucci et al [46] as the nitrogen related to the amide bonds of the peptide backbone. Accordingly to the Cu2p3/2 peak signal approximately 0.04 at.% of Cu species were detected for the laccase mixture powder, and a binding energy of around 933 ± 0.5 eV was obtained [47]. The S2p3/2 signal shows two peaks centered at 163.8 eV for S* H or S* S [48] and 167.9 eV to sulfur oxidized species due to the methionine and cysteine residues.…”

Section: After 20 S Of Immersion Time There Was a Higher Ratio Of [N]mentioning

confidence: 88%

Formation and composition of adsorbates on hydrophobic carbon surfaces from aqueous laccase-maltodextrin mixture suspension

Ureña

Lisboa‐Filho

Szardenings

et al. 2016

Applied Surface Science

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A robust procedure for the surface bio-functionalization of carbon surfaces was developed. It consists on the modification of carbon materials in contact with an aqueous suspension of the enzyme laccase from Trametes versicolor and the lyophilization agent maltodextrin, with the pH value adjusted close to the isoelectric point of the enzyme. We report in-situ investigations applying Quartz Crystal Microbalance with Dissipation (QCM-D) for carbon-coated sensor surfaces and, moreover, ex-situ measurements with static contact angle measurements, X-ray Photoelectron Spectroscopy (XPS) and Scanning Force Microscopy (SFM) for smooth Highly Oriented Pyrolytic Graphite (HOPG) substrates, for contact times between the enzyme formulation and the carbon material surface ranging from 20 s to 24 h. QCM-D studies reveals the formation of rigid layer of biomaterial, a few nanometers thin, which shows a strongly improved wettability of the substrate surface upon contact angle measurements. Following spectroscopic characterization, these layers are composed of mixtures of laccase and maltodextrin. The formation of these adsorbates is attributed to attractive interactions between laccase, the maltodextrin-based lyophilization agent and the hydrophobic carbon surfaces; a short-term contact between the aqueous laccase mixture suspension and HOPG surfaces is shown to merely result in de-wetting patterns influencing the results of contact angle measurements. The new enzyme-based surface modification of carbon-based materials is suggested to be applicable for the improvement of not only the wettability of low energy substrate surfaces with fluid formulations like coatings or adhesives, but also their adhesion in contact with hardened polymers

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Section: After 20 S Of Immersion Time There Was a Higher Ratio Of [N]mentioning

confidence: 88%

Formation and composition of adsorbates on hydrophobic carbon surfaces from aqueous laccase-maltodextrin mixture suspension

Ureña

Lisboa‐Filho

Szardenings

et al. 2016

Applied Surface Science

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“…Recently, a possible mechanism of action associated with copper ion binding has been described. Copper is essential for aerobic life given its presence as a catalytic cofactor for mitochondrial enzymes responsible for ATP synthesis [29, 30]. The available crystallographic and spectroscopic evidence that demonstrates the binding of metal ions to metformin contrasts with the lack of information about its affinity or its regulatory actions over certain proteins [19].…”

Section: Metformin Action Mechanismmentioning

confidence: 99%

To Use or Not to Use Metformin in Cerebral Ischemia: A Review of the Application of Metformin in Stroke Rodents

Arbeláez-Quintero

Palacios

2017

Stroke Research and Treatment

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Ischemic strokes are major causes of death and disability. Searching for potential therapeutic strategies to prevent and treat stroke is necessary, given the increase in overall life expectancy. Epidemiological reports indicate that metformin is an oral antidiabetic medication that can reduce the incidence of ischemic events in patients with diabetes mellitus. Its mechanism of action has not been elucidated, but metformin pleiotropic effects involve actions in addition to glycemic control. AMPK activation has been described as one of the pharmacological mechanisms that explain the action of metformin and that lead to neuroprotective effects. Most experiments done in the cerebral ischemia model, via middle cerebral artery occlusion in rodents (MCAO), had positive results favoring metformin's neuroprotective role and involve several cellular pathways like oxidative stress, endothelial nitric oxide synthase activation, activation of angiogenesis and neurogenesis, autophagia, and apoptosis. We will review the pharmacological properties of metformin and its possible mechanisms that lead to neuroprotection in cerebral ischemia.

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“…Magnetic nano-and microbeads are being widely used for sensing of various biomolecules in different microfluidic systems (Antunes et al, 2015) Kwakye et al, 2006;Steigert et al, 2005;Wang et al, 2013;Zaytseva et al, 2005;Choi et al, 2002). Magnetic beads (MBs) can be utilized for detection of pathogens (Mezger et al, 2015;Beyor et al, 2008;El-Boubbou et al, 2007;Gu et al, 2006;Song et al, 2013;Zaytseva et al, 2005), small molecules (Yang et al, 2016;Wu et al, 2011;Zhang et al, 2013) and proteins (Nam et al, 2003 ;Tsai et al, 2007;Horng et al, 2006), for drug delivery (Chertok et al, 2008;Gonzales and Krishnan, 2005;Jain et al, 2008;Wilson et al, 2005), and even for testing certain characteristics of a drug (Quan et al, 2015). Due to the weak magnetic properties of biomolecules, a readout based on magnetic beads (MBs) is insensitive to chemical and biological parameters that may affect other readout techniques and is thus highly attractive (Yang et al, 2016;Bejhed et al, 2015;Hecht et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Lab-on-a-disc agglutination assay for protein detection by optomagnetic readout and optical imaging using nano- and micro-sized magnetic beads

Uddin

Burger²,

Donolato³

et al. 2016

Biosensors and Bioelectronics

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We present a biosensing platform for the detection of proteins based on agglutination of aptamer coated magnetic nano- or microbeads. The assay, from sample to answer, is integrated on an automated, low-cost microfluidic disc platform. This ensures fast and reliable results due to a minimum of manual steps involved. The detection of the target protein was achieved in two ways: (1) optomagnetic readout using magnetic nanobeads (MNBs); (2) optical imaging using magnetic microbeads (MMBs). The optomagnetic readout of agglutination is based on optical measurement of the dynamics of MNB aggregates whereas the imaging method is based on direct visualization and quantification of the average size of MMB aggregates. By enhancing magnetic particle agglutination via application of strong magnetic field pulses, we obtained identical limits of detection of 25pM with the same sample-to-answer time (15min 30s) using the two differently sized beads for the two detection methods. In both cases a sample volume of only 10µl is required. The demonstrated automation, low sample-to-answer time and portability of both detection instruments as well as integration of the assay on a low-cost disc are important steps for the implementation of these as portable tools in an out-of-lab setting.

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The copper binding properties of metformin – QCM-D, XPS and nanobead agglomeration

Cited by 21 publications

References 36 publications

Formation and composition of adsorbates on hydrophobic carbon surfaces from aqueous laccase-maltodextrin mixture suspension

Formation and composition of adsorbates on hydrophobic carbon surfaces from aqueous laccase-maltodextrin mixture suspension

To Use or Not to Use Metformin in Cerebral Ischemia: A Review of the Application of Metformin in Stroke Rodents

Lab-on-a-disc agglutination assay for protein detection by optomagnetic readout and optical imaging using nano- and micro-sized magnetic beads

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