Publications

Abstract Overproduction of uric acid in the body leads to hyperuricemia, which is also closely related to gout. Uric acid production can be lowered by xanthine oxidase (XO) inhibitors. Inhibition of XO has also been proposed as a mechanism for improving cardiovascular health. Therefore, the search for new efficient XO inhibitors is an interesting topic in drug discovery. 3-Phenylcoumarins and 2-phenylbenzofurans are privileged scaffolds in medicinal chemistry. Their structural similarity makes them interesting molecules for a comparative study. Methoxy and nitro substituents were introduced in both scaffolds. The current study gives some insights into the synthesis and biological activity of these molecules against this important target. For the best compound of the series, the 3-(4-methoxyphenyl)-6-nitrocoumarin (4), the IC50 value, type of inhibition, cytotoxicity on B16F10 cells and ADME theoretical properties, were determined. Docking studies were also performed in order to better understand the interactions of this molecule with the XO binding pocket. This work is a preliminary screening for further design and synthesis of new non-purinergic derivatives as potential compounds involved in the inflammatory suppression, specially related to gout.

Abstract Recent Trends in Biofilm Science and Technology helps researchers working on fundamental aspects of biofilm formation and control conduct biofilm studies and interpret results. The book provides a remarkable amount of knowledge on the processes that regulate biofilm formation, the methods used, monitoring characterization and mathematical modeling, the problems/advantages caused by their presence in the food industry, environment and medical fields, and the current and emergent strategies for their control. Research on biofilms has progressed rapidly in the last decade due to the fact that biofilms have required the development of new analytical tools and new collaborations between biologists, engineers and mathematicians.

Abstract The emergence of multidrug-resistant microorganisms in persistent biofilm infections represents a public health threat. The limited efficacy of currently available antimicrobials has been imposing the search for new approaches to overcome bacterial and fungal biofilm infections. Drug repurposing arises as an interesting strategy that can reduce time, cost, and risk associated with drug innovation. This can be achieved by finding new applications beyond the original medical indication for approved or investigational drugs. This chapter collects the antimicrobial effects known so far against bacteria and fungi caused by different classes of drugs, including antineoplastic, antipsychotic, antidepressant, and antiinflammatory, among others. Besides the action on microbial growth in vitro and in vivo, some of these drugs are also able to synergize with traditional antibiotics and antifungals. Finally, a special focus on antibiofilm activity was included, reveling the promising drugs for biofilm prevention and control.

Abstract The west coast of Tangier, in northern Morocco, has been affected by industrial wastewater discharge that reaches the ocean through the Boukhalef river. Therefore, the Jbila and Sidikacem beaches near to the Boukhalef river mouth have been classified as polluted for many years. With the aim of determining the COVID-19 pandemic consequences on the Tangier coastal environment, a linear model using Sentinel 3 water surface temperature (WST) has been tested in several locations. Data from April 2019 and April 2020, before and during the COVID-19 pandemic related emergency status in Morocco, were compared. The results from April 2019 showed high WST values and consequently, the poorest water quality in the sites closest to the Boukhalef river mouth. On the other hand, the results from April 2020 showed normal WST values and high water quality in the same study area. These results illustrate the usefulness of Sentinel 3 WST for the estimation of bathing water quality on the west coast of Tangier. The study shows the positive impact of the COVID-19 pandemic consequences on the coastal environment quality in the study area and indicates the importance of decreasing the industrial discharge on the west coast of Tangier. The same methodology could be used in decision-making processes and to reduce cost, time and human resources for coastal monitoring systems. We demonstrate the potential of using the Sentinel 3 data for coastal waters monitoring, as well as the need for stricter controls of pollutant discharges into the world's rivers.

Abstract Swept-source optical coherence tomography (SSOCT) is a noncontact, noninvasive bioimaging tool that uses various probes to obtain high contrast images. Rare-earth based upconversion particles (UCPs) provide a unique platform to enhance the capabilities of bioimaging techniques. The UCPs can act as contrast enhancers for the SSOCT with additional optical functionality, and hence in this work upconversion emission optimized polyvinylpyrrolidone (PVP)/NaGdF4:Er3+/Yb3+ UCPs were synthesized and then injected into chicken breast tissues to enhance the SSOCT images. As-synthesized samples have shown good biocompatibility toward HEK293, HeLa cell lines and showed apparent enhancement in contrast to SSOCT images. Additionally, compared to the bare NaGdF4:Er3+/Yb3+ UCPs the polyvinylpyrrolidone-stabilized UCPs have shown 3-fold enhancement in the frequency of upconverted green and red light intensity under 976 nm diode laser excitation (26 W/cm(2)).

Abstract Disinfection is crucial to control and prevent microbial pathogens on surfaces. Nonetheless, disinfectants misuse in routine disinfection has increased the concern on their impact on bacterial resistance and cross-resistance. This work aims to develop a formulation for surface disinfection based on the combination of a natural product, cinnamaldehyde, and a widely used biocide, cetyltrimethylammonium bromide. The wiping method was based on the Wiperator test (ASTM E2967-15) and the efficacy evaluation of surface disinfection wipes test (EN 16615:2015). After formulation optimization, the wiping of a contaminated surface with 6.24 log(10) colony-forming units (CFU) of Escherichia coli or 7.10 log(10) CFU of Staphylococcus aureus led to a reduction of 4.35 log(10) CFU and 4.27 log(10) CFU when the wipe was impregnated with the formulation in comparison with 2.45 log(10) CFU and 1.50 log(10) CFU as a result of mechanical action only for E. coli and S. aureus, respectively. Furthermore, the formulation prevented the transfer of bacteria to clean surfaces. The work presented highlights the potential of a combinatorial approach of a classic biocide with a phytochemical for the development of disinfectant formulations, with the advantage of reducing the concentration of synthetic biocides, which reduces the potentially negative environmental and public health impacts from their routine use.

Abstract In this investigation, hybrid-biocomposites "ZnO-Chitosan" were synthesized using a chitosan biomaterial and various amounts of ZnO particles (7 and 93 wt percent). The chitosan was obtained from the exoskeletons of shrimp shells, which were collected from the fishmongers in Meknes city (Morocco). Several techniques including X-ray diffraction, Fourier transform infrared spectroscopy, differential thermal analysis and thermogravimetric analysis, diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy coupled with energy dispersive spectroscopy were used for the characterization of the synthesized hybrid-biocomposites. The obtained experimental results showed the existence of a strong interaction between Zn-2(+), and the amino and hydroxyl groups of chitosan only for the hybrid-biocomposite containing 7 wt percent of ZnO. This suggests that the structure of this sample is probably formed via a complexation between Zn-2(+) ions which are linked to -NH2, -OH groups of chitosan, and H2O molecules. The photocatalytic activity of the asprepared hybrid-biomaterials was then evaluated by measuring the degradation efficiency of methyl orange (MO) and paranitrophenol (pNP) under both UV-A and visible light irradiation. The obtained results indicated that the photocatalytic performance was significantly improved by adding an optimum amount of ZnO (7 wt %) to the chitosan biomaterial, and suggested that the photocatalytic activity depended closely on the ZnO weight percent. The role of the active species (electrons, holes and hydroxyl radicals) in the photocatalytic process has been studied and the probable degradation mechanisms of MO and pNP under both UV-A and visible light illuminations were proposed.

Abstract In this work, we combined electrochemical techniques with SPR (eSPR) for the label-free detection of cancer biomarker miRNA-145. Detection was performed in a simple two-step assay. In the first step, the gold sensor surface, previously functionalized with a self-assembled monolayer (SAM) of thiolated RNA probes is incubated with the sample containing the target RNA biomarker. In this step, hybridization of RNA fragments with complementary immobilized probes was monitored in real-time by SPR. In the second step, eSPR measurements were performed to improve the sensitivity of the hybridization assay. Potential-induced deposition of a redox probe at the sensor surface resulted in enhanced SPR response promoted by the electrochemical process, thereby allowing the detection of miRNA-145 at femtomolar level (LOD = 0.56 fM), without sample derivatization or post-hybridization treatment for signal amplification. Good linearity was achieved (R-2 = 0.984) over the concentration range from 1.0 fM and 10 nM. Furthermore, the developed eSPR biosensor showed high selectivity towards single-base and two-base mismatch sequences and detection of target miRNA-145 in synthetic human serum was successful achieved.

Abstract In this work, three universally used redox probes in amperometric biosensing devices, [Fe(CN)(6)](3-)/[Fe(CN)(6)](4-), Ru[(NH3)(6)](3+), and ferrocenedimethanol (FDM), were selected to evaluate the stability of electrochemical signals provide by the reporting systems. Studies were carried out at disposable gold screen-printed electrode (AuSPE) biosensing platforms, commonly used for screening chemical and biological relevant biomolecules. Firstly, electrochemical combined-surface plasmon resonance (eSPR) studies were performed to evaluated adsorption reversibility and/or formation of redox probe complexes at the bare gold surface when routinely used electrochemical techniques, namely cyclic voltammetry (CV) and square-wave voltammetry (SWV), are recorded. Then, the results obtained were compared with those obtained at the AuSPE under the same electrochemical conditions. Based on our findings, best experimental conditions, including the type of electrochemical technique used, are speculated for each reporting system in order to improve the analytical signal stability. Finally, a methodology based on SWV technique was applied to modified electrodes to provide a simple and easy tool to ensure diffusion controlled permeability of probes thorough the films to electrode surface.