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1. Physical Chemistry Study of Collagen-Based Multilayer Films

Author

Yi-Wei Chen, Muhammad Haseeb Iqbal, Florent Meyer, Vincent Ball, and Fouzia Boulmedais

Subjects
collagen, polyphenols, layer-by-layer assembly, polyelectrolyte, biocompatible, Science, Chemistry, QD1-999, Inorganic chemistry, QD146-197, General. Including alchemy, QD1-65
Abstract

The surface properties of a biomaterial play an important role in cell behavior, e.g., recolonization, proliferation, and migration. Collagen is known to favor wound healing. In this study, collagen (COL)-based layer-by-layer (LbL) films were built using different macromolecules as a partner, i.e., tannic acid (TA), a natural polyphenol known to establish hydrogen bonds with protein, heparin (HEP), an anionic polysaccharide, and poly(sodium 4-styrene sulfonate) (PSS), an anionic synthetic polyelectrolyte. To cover the whole surface of the substrate with a minimal number of deposition steps, several parameters of the film buildup were optimized, such as the pH value of the solutions, the dipping time, and the salt (sodium chloride) concentration. The morphology of the films was characterized by atomic force microscopy. Built at an acidic pH, the stability of COL-based LbL films was studied when in contact with a physiological medium as well as the TA release from COL/TA films. In contrast to COL/PSS and COL/HEP LbL films, COL/TA films showed a good proliferation of human fibroblasts. These results validate the choice of TA and COL as components of LbL films for biomedical coatings.

Published
2023
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2. Surface Triggered Self-Assembly of Fmoc-Tripeptide as an Antibacterial Coating

Author

Miryam Criado-Gonzalez, Muhammad Haseeb Iqbal, Alain Carvalho, Marc Schmutz, Loïc Jierry, Pierre Schaaf, and Fouzia Boulmedais

Subjects
peptides, hydrogels, antimicrobial, enzyme-assisted self-assembly, nanoparticles, Biotechnology, TP248.13-248.65
Abstract

In western countries, one patient on twenty will develop a nosocomial infection during his hospitalization at health care facilities. Classical antibiotics being less and less effective, this phenomenon is expanding year after year. Prevention of bacteria colonization of implantable medical devices constitutes a major medical and financial issue. In this study, we developed an antibacterial coating based on self-assembled Fmoc-tripeptide. Fmoc-FFpY peptides (F: phenylalanine; Y: tyrosine; p: PO42–) are dephosphorylated enzymatically into Fmoc-FFY by action of alkaline phosphatase functionalized silica nanoparticles (NPs@AP), previously deposited on a surface. Fmoc-FFY peptides then self-assemble through π–π stacking interactions, hydrogen bonds and hydrophobic interactions adopting β-sheets secondary structures. The obtained hydrogel coatings show fibrillary structures observed by cryo-scanning electron microscopy with a thickness of few micrometers. At low concentration (≤0.5 mg.mL–1), self-assembled Fmoc-FFY has a superior antibacterial activity than Fmoc-FFpY peptide in solution. After 24 h of incubation, Fmoc-FFY hydrogel coatings fully inhibit the development of Gram-positive Staphylococcus aureus (S. aureus). The antibacterial effect is maintained on an in vitro model of repetitive infection in the case of S. aureus. This coating could serve in infections were Gram positive bacteria are prevalent, e.g., intravascular catheter infections. This work gives new insights toward the design of an alternative antimicrobial coating.

Published
2020
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3. Plasmonic Resonant Nanoantennas Induce Changes in the Shape and the Intensity of Infrared Spectra of Phospholipids

Author

Fatima Omeis, Zahia Boubegtiten-Fezoua, Ana Filipa Santos Seica, Romain Bernard, Muhammad Haseeb Iqbal, Nicolas Javahiraly, Robrecht M. A. Vergauwe, Hicham Majjad, Fouzia Boulmedais, David Moss, and Petra Hellwig

Subjects
nanoantennas, DPPTE, bilayers, SEIRAS, enhancement, AFM, Organic chemistry, QD241-441
Abstract

Surface enhanced infrared absorption spectroscopic studies (SEIRAS) as a technique to study biological molecules in extremely low concentrations is greatly evolving. In order to use the technique for identification of the structure and interactions of such biological molecules, it is necessary to identify the effects of the plasmonic electric-field enhancement on the spectral signature. In this study the spectral properties of 1,2-Dipalmitoyl-sn-glycero-3 phosphothioethanol (DPPTE) phospholipid immobilized on gold nanoantennas, specifically designed to enhance the vibrational fingerprints of lipid molecules were studied. An AFM study demonstrates an organization of the DPPTE phospholipid in bilayers on the nanoantenna structure. The spectral data were compared to SEIRAS active gold surfaces based on nanoparticles, plain gold and plain substrate (Si) for different temperatures. The shape of the infrared signals, the peak positions and their relative intensities were found to be sensitive to the type of surface and the presence of an enhancement. The strongest shifts in position and intensity were seen for the nanoantennas, and a smaller effect was seen for the DPPTE immobilized on gold nanoparticles. This information is crucial for interpretation of data obtained for biological molecules measured on such structures, for future application in nanodevices for biologically or medically relevant samples.

Published
2021
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4. Brush-Induced Orientation of Collagen Fibers in Layer-by-Layer Nanofilms: A Simple Method for the Development of Human Muscle Fibers

Author

Muhammad Haseeb Iqbal, Faratiana Jeanne Rosine Revana, Emeline Pradel, Varvara Gribova, Kamel Mamchaoui, Catherine Coirault, Florent Meyer, Fouzia Boulmedais, Institut Charles Sadron (ICS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Biomatériaux et Bioingénierie (BB), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche en Biomédecine de Strasbourg (CRBS), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de recherche en Myologie – U974 SU-INSERM, Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Institut Carnot MICA DIAART project, Fonds Régional de Coopération pour la Recherche of Région Grand Est ERMES project and International Centre for Frontier Research in Chemistry (icFRC) are acknowledged for financial support, and Boulmedais, Fouzia

Subjects
[SDV] Life Sciences [q-bio], nano-patterning, Orientation, multilayers, [SDV]Life Sciences [q-bio], [CHIM] Chemical Sciences, General Engineering, [CHIM]Chemical Sciences, General Physics and Astronomy, General Materials Science, myogenesis, polyelectrolyte
Abstract

International audience; The engineering of skeletal muscle tissue, a highly organized structure of myotubes, is promising for the treatment of muscle injuries and muscle diseases, for replacement or pharmacology research. Muscle tissue development involves differentiation of myoblasts into myotubes with parallel orientation, to ultimately form aligned myofibers, which is challenging to achieve on flat surfaces. In this work, we designed hydrogen-bonded tannic acid/collagen layer-by-layer (TA/COL LbL) nanofilms using a simple brushing method to address this issue. In comparison to films obtained by the dipping, brushed TA/COL films showed oriented COL fibers of 60 nm diameter along the brushing direction. Built at acidic pH due to COL solubility, TA/COL films released TA in physiological conditions with a minor loss of thickness. After characterization of COL fibers orientation, human myoblasts (C25CL48) were seeded on the oriented TA/COL film, ended by COL. After 12 days in a differentiation medium without any other supplement, human myoblasts were able to align on brushed TA/COL films and to differentiate into long aligned myotubes (from hundreds of nm up to 1.7 mm length) thanks to two distinct properties: (i) the orientation of COL fibers guiding myoblasts alignment, and (ii) the TA release favoring the differentiation. This simple and potent brushing process allows the development of anisotropic tissues in vitro which can be used for studies of drug discovery and screening or the replacement of damaged tissue.

Published
2022
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6. Effect of the Buffer on the Buildup and Stability of Tannic Acid/Collagen Multilayer Films Applied as Antibacterial Coatings

Author

Muhammad Haseeb Iqbal, André P. Schroder, Fouzia Boulmedais, Vincent Ball, Christian Njel, Florent Meyer, Halima Kerdjoudj, Bernard Senger, Institut Charles Sadron (ICS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Biomatériaux et inflammation en site osseux - EA 4691 (BIOS), Université de Reims Champagne-Ardenne (URCA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-SFR CAP Santé (Champagne-Ardenne Picardie Santé), Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV), Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Biomatériaux et Bioingénierie (BB), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Matériaux et nanosciences d'Alsace, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Boulmedais, Fouzia

Subjects
Staphylococcus aureus, Materials science, layer-by-layer, [PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], Microbial Sensitivity Tests, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Citric Acid, polyelectrolytes, chemistry.chemical_compound, Drug Delivery Systems, Coated Materials, Biocompatible, Tannic acid, Escherichia coli, Humans, General Materials Science, citrate, ComputingMilieux_MISCELLANEOUS, polyphenols, Deposition (law), Antibacterial agent, [CHIM.MATE] Chemical Sciences/Material chemistry, [PHYS.PHYS.PHYS-BIO-PH] Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], Layer by layer, [CHIM.MATE]Chemical Sciences/Material chemistry, Fibroblasts, 021001 nanoscience & nanotechnology, Antimicrobial, Polyelectrolyte, Anti-Bacterial Agents, 0104 chemical sciences, chemistry, Polyphenol, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], antimicrobial, Collagen, 0210 nano-technology, Tannins, Layer (electronics), Nuclear chemistry
Abstract

The deposition of polyelectrolyte multilayers, obtained by the layer-by-layer (LbL) method, is a well-established technology to design biocompatible and antibacterial coatings aimed at preventing implant-associated infections. Several types of LbL films have been reported to exhibit antiadhesive and/or antibacterial (contact-killing or release-killing) properties governed not only by the incorporated compounds but also by their buildup conditions or their postbuildup treatments. Tannic acid (TA), a natural polyphenol, is known to inhibit the growth of several bacterial strains. In this work, we developed TA/collagen (TA/COL) LbL films built in acetate or citrate buffers at pH 4. Surprisingly, the used buffer impacts not only the physicochemical but also the antibacterial properties of the films. When incubated in physiological conditions, both types of TA/COL films released almost the same amount of TA depending on the last layer and showed an antibacterial effect against Staphylococcus aureus only for citrate-built films. Because of their granular topography, TA/COL citrate films exhibited an efficient release-killing effect with no cytotoxicity toward human gingival fibroblasts. Emphasis is put on a comprehensive evaluation of the physicochemical parameters driving the buildup and the antibacterial property of citrate films. Specifically, complexation strengths between TA and COL are different in the presence of the two buffers affecting the LbL deposition. This work constitutes an important step toward the use of polyphenols as an antibacterial agent when incorporated in LbL films.

Published
2020
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7. A Cost Utility Analysis of Minimally Invasive Surgery with Thrombolysis Compared to Standard Medical Treatment in Spontaneous Intracerebral Haemorrhagic Stroke

Author

Haseeb Iqbal, Arwa Hagana, Kajal Ruparell, Nuha Rabee, Arian Arjomandi Rad, Mohammad Mahmud, Raad Shakir, William Poole, Robert Vardanyan, and Javad Khan

Subjects
medicine.medical_specialty, Time Factors, Cost effectiveness, medicine.medical_treatment, Cost-Benefit Analysis, Economic, State Medicine, 03 medical and health sciences, 0302 clinical medicine, Models, medicine, Minimally Invasive Surgical Procedures/adverse effects, Minimally Invasive Surgical Procedures, Humans, Thrombolytic Therapy, Intensive care medicine, Adverse effect, health care economics and organizations, Thrombolytic Therapy/adverse effects, Intracerebral hemorrhage, Cost–utility analysis, Medical treatment, business.industry, Rehabilitation, Hemorrhagic Stroke/diagnostic imaging, Thrombolysis, Health Care Costs, medicine.disease, United Kingdom, Hemorrhagic Stroke, Models, Economic, Treatment Outcome, Invasive surgery, Economic evaluation, Quality of Life, Surgery, State Medicine/economics, Neurology (clinical), Quality-Adjusted Life Years, Cardiology and Cardiovascular Medicine, business, 030217 neurology & neurosurgery
Abstract

OBJECTIVES: Standard medical management of spontaneous intracerebral haemorrhage (ICH) and surgical hematoma evacuation starkly differ, and whilst landmark randomised control trials report no clinical benefit of early surgical evacuation compared with medical treatment in supratentorial ICH, minimally invasive surgery (MIS) with thrombolysis has been neglected within these studies. However, recent technological advancements in MIS have renewed interest in the surgical treatment of ICH. Several economic evaluations have focused on the benefits of MIS in ischaemic stroke management, but no economic evaluations have yet been performed comparing MIS to standard medical treatment for ICH.MATERIALS AND METHOD: All costs were sourced from the UK in GBP. Where possible, the 2019/2020 NHS reference costs were used. The MISTIE III study was used to analyse the outcomes of patients undergoing either MIS or standard medical treatment in this economic evaluation.RESULTS: The incremental cost-effectiveness ratio (ICER) for MIS was £485,240.26 for every quality-adjusted life year (QALY) gained. Although MIS resulted in a higher QALY compared to medical treatment, the gain was insignificant at 0.011 QALY. Four sensitivity analyses based on combinations of alternative EQ-5D values and categorisation of MIS outcomes, alongside alterations to the cost of significant adverse events, were performed to check the robustness of the ICER calculation. The most realistic sensitivity analysis showed a potential increase in cost effectiveness when clot size is reduced to DISCUSSION: From the perspective of the NHS, MIS with thrombolysis is not cost-effective compared to optimal medical treatment. ICER shows that intention-to-treat MIS would require a cost of £485,240.26 to gain one extra QALY, which is significantly above the NHS threshold of £30,000. Further UK studies with ICH survivor utilities, more replicable surgical technique, and the reporting of clot size reduction are indicated as the present sensitivity analysis suggests that MIS is promising. Greater detail about outcomes and complications would ensure improved cost-benefit analyses and support valid and efficient allocation of resources by the NHS.

Published
2021
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8. Diagnostic Accuracy of Diffusion Weighted MRI in Diagnosing Brain Abscess Taking Histopathology as Gold Standard

Author

M. Haseeb Iqbal, Ummara Siddique Umer, Muhammad Salman Rafique, Abdullah Safi, Sana Kundi, Mahwish Jabeen, and Aliya Sharif

Abstract

Aim: Diagnostic accuracy of DW-MRI in diagnosing brain abscess taking histopathology as gold standard. Methodology: A total of 407 patients having focal brain lesion on MRI of age 20-50 years of either gender were included. Patients with history of brain surgery, already established diagnosis on histopathology, claustrophobia and pregnant or breast feeding females were excluded. DW-MRI was done and conventional MRI sequences on 1.5 tesla MRI machine and presence or absence of brain abscess was noted. DW-MRI findings were correlated with histopathology. Results: Mean age was 38.53 ± 7.59 years. Out of these 407 patients, 262 (64.37%) were male and 145 (35.63%) were females with ratio of 1.8:1. Mean duration of disease was 4.87 ± 2.40 months. Mean size of lesion was 7.69 ± 4.52 mm. In DW-MRI positive patients, 221 were true positive and 32 were false positive. Among 154, DW-MRI negative patients, 18 were false negative whereas 136 were true negative (P-value=0.01). So in diagnosis of abscess in brain, sensitivity, specificity, PPV, NPV and DA of DW-MRI was 92.5%, 80.96%, 87.4%, 88.3% and 87.7% respectively. Conclusion: DW-MRI is the non-invasive modality of choice having high diagnostic accuracy (DA) i.. 87.7% in diagnosing brain abscess with sensitivity of 92.5% and specificity of 80.96%. Keywords: Brain abscess, diffusion weighted imaging, sensitivity.

Published
2022
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9. Supramolecular tripeptide self-assembly initiated at the surface of coacervates by polyelectrolyte exchange

Author

Alain Carvalho, Pierre Schaaf, Loïc Jierry, Déborah Wagner, Muhammad Haseeb Iqbal, Marc Schmutz, Aymeric Ontani, Fouzia Boulmedais, Joseph B. Schlenoff, Miryam Criado-Gonzalez, Institut Charles Sadron (ICS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Florida State University [Tallahassee] (FSU), Biomatériaux et Bioingénierie (BB), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Boulmedais, Fouzia, Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Matériaux et nanosciences d'Alsace (FMNGE), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Supramolecular chemistry, Aucun, Peptide, 02 engineering and technology, Tripeptide, 010402 general chemistry, 01 natural sciences, Allylamine, Biomaterials, chemistry.chemical_compound, Colloid and Surface Chemistry, [CHIM] Chemical Sciences, [CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, [CHIM.MATE] Chemical Sciences/Material chemistry, Coacervate, Chemistry, Layer by layer, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Polyelectrolytes, Polyelectrolyte, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Chemical engineering, Self-assembly, Peptides, 0210 nano-technology
Abstract

Spatial control of supramolecular self-assembly can yield compartmentalized structures, a key feature for the design of artificial cells. Inducing self-assembly from and on compartments is still a challenge. Polyelectrolyte complex coacervates are simple model droplet systems able to reproduce the basic features of membrane-less organelles, appearing in cells. Here, we demonstrate the supramolecular self-assembly of a phosphorylated tripeptide, Fmoc-FFpY (Fmoc: fluorenyl-methoxycarbonyl; F: phenyl alanine, pY: phosphorylated tyrosine), on the surface of poly(l-glutamic acid)/poly(allylamine hydrochloride) (PGA/PAH) complex coacervate microdroplets. The phosphorylated peptides self-assemble, without dephosphorylation, through ion pairing between the phosphate groups of Fmoc-FFpY and the amine groups of PAH. This process provides spontaneous capsules formed by an amorphous polyelectrolyte complex core surrounded by a structured peptide/PAH shell. Similar fibrillar Fmoc-FFpY self-assembled structures are obtained at the interface between the peptide solution and a PGA/PAH polyelectrolyte multilayer, a complex coacervate in the thin film or "multilayer" format. In contact with the peptide solution, PAH chains diffuse out of the coacervate or multilayer film and complex with Fmoc-FFpY at the solution interface, exchanging any PGA with which they were associated. Self-assembly of Fmoc-FFpY, now concentrated by complexation with PAH, follows quickly. Keywords: Coacervates; Fmoc-FF; Layer-by-layer; Multilayers; Peptides; Polyelectrolytes; Supramolecular self-assembly.

Published
2021
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10. Changing Student Perception of an Online Integrated Structured Clinical Examination During the COVID-19 Pandemic [Letter]

Author

Haseeb Iqbal, Musab Hasan, and Shayaan Akhtar

Subjects
medicine.medical_specialty, 2019-20 coronavirus outbreak, Letter, Coronavirus disease 2019 (COVID-19), medicine.diagnostic_test, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), media_common.quotation_subject, MEDLINE, Physical examination, Education, Family medicine, Perception, Pandemic, medicine, Advances in Medical Education and Practice, Psychology, media_common
Abstract

Shayaan Akhtar, Musab Hasan, Haseeb Iqbal Faculty of Medicine, Department of Medicine, Imperial College School of Medicine, London, UKCorrespondence: Shayaan AkhtarFaculty of Medicine, Imperial College London, Sir Alexander Fleming Building, Imperial College Road, London, SW7 2AZ, UKEmail shayaan.akhtar16@imperial.ac.uk View the original paper by Dr Ganesananthan and colleagues

Published
2021
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11. Study of Membrane Protein Monolayers Using Surface-Enhanced Infrared Absorption Spectroscopy (SEIRAS): Critical Dependence of Nanostructured Gold Surface Morphology

Author

Ana Filipa Santos Seica, Muhammad Haseeb Iqbal, Fouzia Boulmedais, Petra Hellwig, Alain Carvalho, Jun-yong Choe, Chimie de la matière complexe (CMC), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Sadron (ICS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), East Carolina University [Greenville] (ECU), University of North Carolina System (UNC), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), and Boulmedais, Fouzia

Subjects
Nanostructure, Materials science, Silicon, Spectrophotometry, Infrared, Scanning electron microscope, Surface Properties, chemistry.chemical_element, Nanoparticle, Infrared spectroscopy, Bioengineering, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Monolayer, Spectroscopy, Instrumentation, Fluid Flow and Transfer Processes, [CHIM.MATE] Chemical Sciences/Material chemistry, Process Chemistry and Technology, Membrane Proteins, Reproducibility of Results, Self-assembled monolayer, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Nanostructures, chemistry, Chemical engineering, Gold, 0210 nano-technology
Abstract

International audience; Surface-enhanced infrared absorption spectroscopy (SEIRAS) is a powerful tool that allows studying the reactivity of protein monolayers at very low concentrations and independent from the protein size. In this study, we probe the surface’s morphology of electroless gold deposition for optimum enhancement using two different types of immobilization adapted to two proteins. Independently from the mode of measurement (i.e., transmission or reflection) or type of protein immobilization (i.e., through electrostatic interactions or nickel-HisTag), the enhancement and reproducibility of protein signals in the infrared spectra critically depended on the gold nanostructured surface morphology deposited on silicon. Just a few seconds deviation from the optimum time in the nanoparticle deposition led to a significantly weaker enhancement. Scanning electron microscopy and atomic force microscopy measurements revealed the evolution of the nanostructured surface when comparing different deposition times. The optimal deposition time led to isolated gold nanostructures on the silicon crystal. Importantly, in the case of the immobilization using nickel-HisTag, the surface morphology is rearranged upon immobilization of linker and the protein. A complex three-dimensional (3D) network of nanoparticles decorated with the protein could be observed leading to the optimal enhancement. The electroless deposition of gold is a simple technique, which can be adapted to flow cells and used in analytical approaches.

Published
2021
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12. Sedimentation and stabilization of nano-fluids with dispersant

Author

Shahid Raza Malik, Muhammad Abdullah, Muhammad Munir Sajid, Yasir Javed, Syed Zajif Hussain, Muhammad Haseeb Iqbal, Wasif Razzaq, and Naveed Akhtar Shad

Subjects
Poly(methacrylic acid), Materials science, 020209 energy, Nanoparticle, 02 engineering and technology, Sedimentation, 021001 nanoscience & nanotechnology, Dispersant, chemistry.chemical_compound, Colloid and Surface Chemistry, Nanofluid, Isoelectric point, chemistry, Chemical engineering, 0202 electrical engineering, electronic engineering, information engineering, Zeta potential, 0210 nano-technology, Dispersion (chemistry)
Abstract

Stability of nanofluids is one of the major parameters which measures its effectiveness. The agglomeration of nanoparticles reduces the stability of nanofluids and consequently affects their technologically relevant properties. In this study, stability of alumina nanoparticles (size ∼ 50 nm) in ethanol-water mixture with and without dispersant has been investigated. Sodium salt of poly methacrylic acid (SPMAA) as a dispersant were used in this investigation. Clear solution height with respect to time, sedimentary photographs and zeta potential techniques have been used to analyze the stability behavior of nano-fluid. The effect of binary mixture proportions and dispersion’s pH has been investigated and discussed. The results showed that sedimentation, zeta potential and photographic techniques have a great correspondence with each other. SPMAA has been used as the dispersant in low concentration (0.03 ml) and has a negative impact on the stability of nano-fluids. The isoelectric point of alumina found to be at pH 7 but with dispersant shifted towards acidic region (pH 4.5). Higher binary mixture concentrations (10% and 90%) by weight exhibited good stability.

Published
2018
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13. Noting Voices : Contemplating London's Culture

Author

Haseeb Iqbal and Haseeb Iqbal

Abstract

Noting Voices: Contemplating London's Culture is author Haseeb Iqbal's take on the bubbling'London Jazz Scene'and live music explosion that has consumed the capital in recent years. Having grown up within it all, Haseeb focuses on the spaces that have aided a scene so rich and layered, basing his reflections on five conversations from his'Mare Street Records'podcast. He maps the scene's growth via the perspective of those who have provided the space, appreciating the instrumental role of such environments and the figureheads who have driven them. He navigates the unconventional template many of these spaces have observed, dissecting how a cultural movement, now internationally acclaimed, found its voice and established its identity. This story takes it back to the grassroots spaces and DIY communities who can be forgotten when an underground movement turns more mainstream. It appreciates a set of community-based values that have underpinned a radical cultural shift in London's sound, acknowledging the role of gentrification throughout, and the threat it poses to the spaces that birth and nurture this culture.

Published
2021

14. Unexpected aqueous UCST behavior of a cationic comb polymer with pentaarginine side chains

Author

Nicolas Zydziak, Delphine Chan-Seng, Mélanie Legros, Antoine Combes, Philippe Lavalle, Emeric Wasielewski, Fouzia Boulmedais, Alain Chaumont, Loïc Jierry, Muhammad Haseeb Iqbal, Institut Charles Sadron (ICS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Chimie de la matière complexe (CMC), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'innovation moléculaire et applications (LIMA), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Biomatériaux et Bioingénierie (BB), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Matériaux et nanosciences d'Alsace (FMNGE), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Polymers and Plastics, General Physics and Astronomy, arginine, 02 engineering and technology, 010402 general chemistry, Methacrylate, 01 natural sciences, Hydrophobic effect, Coulomb-defying interaction, Upper critical solution temperature, Materials Chemistry, [CHIM]Chemical Sciences, Thermoresponsive polymers in chromatography, guanidinium self-association, chemistry.chemical_classification, Organic Chemistry, Cationic polymerization, Chain transfer, Polymer, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, Chemical engineering, Polymerization, Thermoresponsive polymer, upper critical solution temperature, 0210 nano-technology, Chimie/Polymères
Abstract

International audience; Thermoresponsive polymers, undergoing a reversible chemical or physical change using temperature as stimulus, attract increasing interest in particular as adaptable biomaterials. Except for zwitterionic polymers, fully charged polymers require the presence of specific ions to exhibit an upper critical solution temperature (UCST) in water. Herein, we report the discovery of an UCST in pure water for fully cationic comb polymers based on oligoarginine pendent grafts. These polymers were prepared using an original strategy based on solid-phase peptide synthesis of pentaarginine methacrylate-based macromonomer and its polymerization through reversible addition-fragmentation chain transfer. Despite their cationic nature, guanidinium groups from the arginine have the ability to self-associate at low temperature through hydrophobic interactions into stacked pair configuration defying the expected Coulomb interactions. These results pave the way to biomedical applications such as antimicrobial materials and drug delivery systems through the tuning of the polymer structure.

Published
2020
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15. Frequency Of Re-Bleeding After Successful Endoscopic Management Of Esophageal Varices In Cirrhotic Patients

Author

Dr. Hina Fatima, Dr. Ziyad Humayun Akhtar, Dr. Mudassar Hussain, Dr. Haseeb Iqbal, Dr Bushra Ali, Dr. Arif Amir Nawaz

Subjects
Cirrhosis of liver, Esophageal variceal banding, Re-bleeding
Abstract

In nearly 50% of cirrhotic patients gastroesophageal varices are present at the time of diagnosis. Each episode of esophageal bleeding is associated with 30-70% risk of mortality. Patients treated with EVBL had a decreased risk of first bleeding episode by 64% and mortality by 45%. Objective: To assess the rebleeding rate in 4 weeks after successful endoscopic variceal band ligation in cirrhotics. Methods: The retrospective observational analysis of endoscopic band ligation procedures, performed in Fatima Memorial Hospital, Lahore during the period January 2016– February 2018, was made. 80 endoscopic band ligation procedures were included in the study. Patients with rebleeding were recorded presenting in four weeks. Results: 80 cases with history of cirrhosis and previous band ligation were chosen for the study. Out of which 49 (61.3%) were male and 31 (38.8) were female with median age of 51.32±12.57. Cause of liver cirrhosis was identified as 63(78.8%), 5(6.3%) and 12(15%) for hepatitis C, hepatitis B and Non B, Non C respectively. Out of 80, 13(16.2%) patients presented with rebleeding in 4 weeks post band ligation. 12(92.3%) out of 13 patients with rebleeding had child pugh class C and had more than 2 columns of esophageal varices. Conclusion: Endoscopic variceal band ligation was found to be an effective modality in reducing the frequency of rebleeding in cirrhotic patients. Re-bleeding after variceal banding was 16.2 %. Major factors contributing to re-bleeding were number of columns of esophageal varices and severity of liver cirrhosis. Keywords: Cirrhosis of liver, Esophageal variceal banding, Re-bleeding.

Published
2018
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18. 1043 Effect of Dose Modification of Ribavirin on SVR 12 in Difficult to Treat Patients on Sofosbuvir, Daclatasvir Based DAA Therapy for Chronic HCV

Author

Asad Chowdhry, Zohaib Khan, Saherish Riaz, Bushra Ali, Shahmeer Nawaz, Arif Nawaz, Hafsa Chaudhry, and Haseeb Iqbal

Subjects
medicine.medical_specialty, Daclatasvir, Hepatology, Sofosbuvir, business.industry, Ribavirin, Gastroenterology, chemistry.chemical_compound, chemistry, Internal medicine, medicine, business, medicine.drug, Dose Modification
Published
2019
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19. 2973 Can BE3A Score Predict Improved Outcomes in Patients With Decompensated Cirrhosis Receiving Direct-Acting Antiviral Therapy for Hepatitis C Virus Infection?

Author

Asad Chowdhry, Zohaib Khan, Bushra Ali, Arif Nawaz, Abdul Farooq, Ayesha Arif, Abru Arshad, Shahmeer Nawaz, Saherish Riaz, Hafsa Chaudhry, and Haseeb Iqbal

Subjects
medicine.medical_specialty, Hepatology, business.industry, Hepatitis C virus, Gastroenterology, Antiviral therapy, Decompensated cirrhosis, medicine.disease_cause, Internal medicine, medicine, In patient, business, Direct acting
Published
2019
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