Tag Archive for: QCMD

Scientific publication

Silk Sericin/Chitosan Supramolecular Multilayered Thin Films as Sustainable Cytocompatible Nanobiomaterials

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Authors: Miguel Rosas, Cristiana F. V. Sousa, Ana Pereira, Adérito J. R. Amaral, Tamagno Pesqueira, Sónia G. Patrício, Sara Fateixa, Helena I. S. Nogueira, João F. Mano, Ana L. Oliveira, and João Borges

Journal: Biomacromolecules

Abstract: Silk sericin (SS) has been widely discarded as a waste by the silk textile industry during the degumming process to obtain fibroin. However, in the past decade, an in-depth understanding of its properties and functions turned it into a high added-value biomaterial for biomedical applications. Herein, we report the molecular design and development of sustainable supramolecular multilayered nanobiomaterials encompassing SS and oppositely charged chitosan (CHT) through a combination of self-assembly and electrostatically driven layer-by-layer (LbL) assembly technology. The successful buildup of SS/CHT multilayered nanobiomaterials was demonstrated by the quartz crystal microbalance with dissipation monitoring and attenuated total reflectance-Fourier transform infrared spectroscopy, and the nanofilms’ wettable properties and nanofibrillar-like topography were shown by water contact angle, atomic force microscopy, and scanning electron microscopy. In vitro assays demonstrated the cytocompatibility of the LbL nanofilms toward human primary dermal fibroblasts, holding great promise as biofunctional nanocoatings for drug/therapeutics/cell delivery, tissue engineering, and regenerative medicine.

 

 

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Publication on AWSensors technology

Site-specific sulfations regulate the physicochemical properties of papillomavirus–heparan sulfate interactions for entry

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Authors: Fouzia Bano, Laura Soria-Martinez, Dominik van Bodegraven, Konrad Throsteinsson, Anna M. Brown, Ines Fels, Nicole L. Snyder, Marta Bally, Mario Schelhaas

Journal: Science Advances

Abstract: Certain human papillomaviruses (HPVs) are etiological agents for several anogenital and oropharyngeal cancers. During initial infection, HPV16, the most prevalent cancer-causing type, specifically interacts with heparan sulfates (HSs), not only enabling initial cell attachment but also triggering a crucial conformational change in viral capsids termed structural activation. It is unknown, whether these HPV16-HS interactions depend on HS sulfation patterns. Thus, we probed potential roles of HS sulfations using cell-based functional and physicochemical assays, including single-molecule force spectroscopy. Our results demonstrate that N-sulfation of HS is crucial for virus binding and structural activation by providing high-affinity sites, and that additional 6O-sulfation is required to mechanically stabilize the interaction, whereas 2O-sulfation and 3O-sulfation are mostly dispensable. Together, our findings identify the contribution of HS sulfation patterns to HPV16 binding and structural activation and reveal how distinct sulfation groups of HS synergize to facilitate HPV16 entry, which, in turn, likely influences the tropism of HPVs.

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Quartz crystal microbalance with dissipation monitoring for studying soft matter at interfaces

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Authors: Diethelm Johannsmann & Ilya Reviakine

Journal: Nature Reviews Methods Primers

Abstract: Quartz crystal microbalance with dissipation monitoring (QCM-D) probes interfaces by subjecting them to a periodic shear stress exerted by an acoustic resonator. The changes in the resonance frequency, Δf, and the half-width at half-maximum of the resonance, ΔΓ (closely related to the changes in the dissipation, ΔD), measured with the QCM-D are proportional to the in-phase and out-of-phase components of the area-averaged transverse stress at the resonator surface, respectively. Amounts, organization and properties of soft matter at an interface between the resonator and a liquid or a gas are derived from the measurements of Δf and ΔΓ on multiple overtones at megahertz frequencies. The properties include viscoelasticity and stress relaxation dynamics on the timescale of the oscillation period. This Primer offers guidelines on instrument design, experimental procedures and data analysis for interpreting frequency and bandwidth changes in terms of structure and dynamics of the sample. There is a focus on recent progress in the analysis of the acoustic ratio, ΔΓ/(−Δf), and numerical methods of modelling. Limitations of the existing approaches for data analysis are discussed. Challenges and possible future developments are formulated in an outlook.

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Scientific publication

Demonstrating a Quartz Crystal Microbalance with Dissipation (QCMD) to Enhance the Monitoring and Mechanistic Understanding of Iron Carbonate Crystalline Films

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Authors: Igor Efimov, Eftychios Hadjittofis, Mustafa M. Alsalem, and Kyra L. Sedransk Campbell

Journal: Langmuir

Abstract:

This paper reports the real time monitoring of siderite deposition, on both Au- and Fe-coated surfaces, using the changes in frequency and dissipation of quartz crystal microbalance with dissipation (QCMD). In an iron chloride solution saturated with carbon dioxide, buffered with sodium bicarbonate to pH 6.8, roughly spherical particles of siderite formed within 15 min, which subsequently deposited on the QCMD crystal surface. Imaging of the surface showed a layer formed from particles ca. < 0.5 μm in diameter. Larger particles are clearly deposited on top of the lower layer; these larger particles are >1 μm in diameter. Monitoring of the frequency clearly differentiates the formation of the lower layer from the larger crystals deposited on top at later times. The elastic moduli calculated from QCMD data showed a progressive dissipation increase; the modeling of the solid–liquid interface using a flat approximation resulted in a poor estimation of elastic and storage moduli. Rather, the impedance modeled as a viscoelastic layer in contact with a semi-infinite liquid, where a random bumpy surface with a Gaussian correlator is used, is much more accurate in determining the elastic and storage moduli as losses from the uneven interface are considered. A further step considers that the film is in fact a composite consisting of hard spherical particles of siderite with water in the vacant spaces. This is treated by considering the individual contributions of the phases to the losses measured, thereby further improving the accuracy of the description of the film and the QCMD data. Collectively, this work presents a new framework for the use of QCMD, paired with traditional approaches, to enhance the understanding of crystal deposition and film formation as well as quantify the often evolving mechanical properties.

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Scientific publication

A low-cost microfluidic flow stabilizer for enhancing QCM measurement stability in in-liquid bio-applications

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Authors: Mohamed Adel, Ahmed Allam, Ashraf E Sayour, Hani F Ragai, Shinjiro Umezu and Ahmed M R Fath El-Bab

Journal: Eng. Res. Express

Abstract

Quartz crystal microbalance (QCM) is a powerful sensing technique widely used in various applications, including biosensing, chemical analysis, and material science. In in-liquid applications, QCM measurements are susceptible to fluctuations in fluid flow rate, which can introduce unwanted noise and compromise the accuracy and reliability of the measurements. In this work, we present an approach to enhance the stability of QCM measurements by utilizing a microfluidic flow stabilizer. The flow stabilizer is designed to minimize flow rate fluctuations, thereby reducing the impact of hydrodynamic effects on the QCM frequency response. We employ a comprehensive methodology that combines computational fluid dynamics (CFD) simulations using ANSYS Fluent software, microfabrication, and experimental testing to evaluate the effectiveness of the flow stabilizer in mitigating flow-induced fluctuations and improving the reliability of QCM measurements. For fabrication, we use direct engraving with a CO2 laser beam on polymethyl methacrylate (PMMA) material to drastically reduce the fabrication cost (to <40 cents) and fabrication time (to 35 min) of the microfluidic chip. Two different designs have been presented and tested: one with a single air reservoir and the other with two reservoirs. Two distinct setups employing a peristaltic pump and a micropump, along with a high fundamental frequency of 50 MHz QCM sensor, were utilized for comprehensive testing in this study. The experimental results demonstrated that the first and second designs of the microfluidic flow stabilizer effectively reduced the fluctuation amplitude in QCM measurements from 100% (input) to 23% and 19% (output), respectively.

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Scientific publication

Real-time monitoring of dephosphorylation process of phosphopeptide and rapid assay of PTP1B activity based on a 100 MHz QCM biosensing platform

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Authors: Shuping Liu, Qingqing Zhang, Xiaohua Zhang, Cuicui Du, Jinhua Chen, Shihui Si

Journal: Talanta

Abstract

The misregulation of protein phosphatases is a key factor in the development of many human diseases, notably cancers. Here, based on a 100 MHz quartz crystal microbalance (QCM) biosensing platform, the dephosphorylation process of phosphopeptide (P-peptide) caused by protein tyrosine phosphatase 1B (PTP1B) was monitored in real time for the first time and PTP1B activity was assayed rapidly and sensitively. The QCM chip, coated with a gold (Au) film, was used to immobilized thiol-labeled single-stranded 5′-phosphate-DNAs (P-DNA) through Au–S bond. The P-peptide, specific to PTP1B, was then connected to the P-DNA via chelation between Zr4+ and phosphate groups. When PTP1B was injected into the QCM flow cell where the P-peptide/Zr4+/MCH/P-DNA/Au chip was placed, the P-peptide was dephosphorylated and released from the Au chip surface, resulting in an increase in the frequency of the QCM Au chip. This allowed the real-time monitoring of the P-peptide dephosphorylation process and sensitive detection of PTP1B activity within 6 min with a linear detection range of 0.01–100 pM and a detection limit of 0.008 pM. In addition, the maximum inhibitory ratios of inhibitors were evaluated using this proposed 100 MHz QCM biosensor. The developed 100 MHz QCM biosensing platform shows immense potential for early diagnosis of diseases related to protein phosphatases and the development of drugs targeting protein phosphatases.

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Acoustic detection of a mutation-specific Ligase Chain Reaction based on liposome amplification

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Authors: Nikoletta Naoumi, Monica Araya-Farias, Maria Megariti, Lucile Alexandre, George Papadakis, Stephanie Descroix, and Electra Gizeli

Journal: Analyst

Abstract

Single nucleotide variants (SNVs) play a crucial role in understanding genetic diseases, cancer development, and personalized medicine. However, existing ligase-based amplification and detection techniques, such as Rolling Circle Amplification and Ligase Detection Reaction, suffer from low efficiency and difficulties in product detection. To address these limitations, we propose a novel approach that combines Ligase Chain Reaction (LCR) with acoustic detection using highly dissipative liposomes. In our study, we are using LCR combined with biotin- and cholesterol-tagged primers to produce amplicons also modified at each end with a biotin and cholesterol molecule. We then apply the LCR mix without any purification directly on a neutravidin modified QCM device Au-surface, where the produced amplicons can bind specifically through the biotin end. To improve sensitivity, we finally introduce liposomes as signal enhancers. For demonstration, we used the detection of the BRAF V600E point mutation versus the wild-type allele, achieving an impressive detection limit of 220 aM of the mutant target in the presence of the same amount of the wild type. Finally, we combined the assay with a microfluidic fluidized bed DNA extraction technology, offering the potential for semi-automated detection of SNVs in patients’ crude samples. Overall, our LCR/acoustic method outperforms other LCR-based approaches and surface ligation biosensing techniques in terms of detection efficiency and time. It effectively overcomes challenges related to DNA detection, making it applicable in diverse fields, including genetic disease and pathogen detection.

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Publication on AWSensors technology

Quartz crystal microbalance in soft and biological interfaces

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Authors: Ilya Reviakine

Journal: Biointephases (2024)

 

Abstract


Applications of quartz crystal microbalance with dissipation to studying soft and biological interfaces are reviewed. The focus is primarily on data analysis through viscoelastic modeling and a model-free approach focusing on the acoustic ratio. Current challenges and future research and development directions are discussed.

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QCMD Data Analysis with PyQTM

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AWsensors Technology Note, video, and executable QCMD Data Analysis with PyQTM.

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Publication on AWSensors technology

C60-based Multivalent Glycoporphyrins Inhibit SARS-CoV-2 Specific Interaction with the DC-SIGN Transmembrane Receptor

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Authors: Jennifer Patino-Alonso, Justo Cabrera-González, Javier Merino, Gema Nieto-Ortiz, Fátima Lasala, Jouma Katati, Carlos H. Bezerra da Cruz, Ajay K. Monnappa, Pablo Mateos-Gil, Ángeles Canales, Iván López-Montero, Beatriz M. Illescas, Rafael Delgado, and Nazario Martín

Journal: Small (2023)

 

Abstract

Since WHO has declared the COVID-19 outbreak a global pandemic, nearly seven million deaths have been reported. This efficient spread of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is facilitated by the ability of the spike glycoprotein to bind multiple cell membrane receptors. Although ACE2 is identified as the main receptor for SARS-CoV-2, other receptors could play a role in viral entry. Among others, C-type lectins such as DC-SIGN are identified as efficient trans-receptor for SARS-CoV-2 infection, so the use of glycomimetics to inhibit the infection through the DC-SIGN blockade is an encouraging approach. In this regard, multivalent nanostructures based on glycosylated [60]fullerenes linked to a central porphyrin scaffold have been designed and tested against DC-SIGN-mediated SARS-CoV-2 infection. First results show an outstanding inhibition of the trans-infection up to 90%. In addition, a deeper understanding of nanostructure-receptor binding is achieved through microscopy techniques, high-resolution NMR experiments, Quartz Crystal Microbalance experiments, and molecular dynamic simulations.

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