Moulay Sadiki

Preparation and optimization of a drug delivery system based on berberine chloride-immobilized MgAl hydrotalcite

Hydrotalcite (HT), also known as a layered double hydroxide (LDH) compound, has been widely used in past years in the formulation of drugs due to its specific properties including good biocompatibility, null toxicity, high chemical stability and pH-dependent solubility which aid in drug controlled release. In this work, berberine chloride (BBC) class antibacterial agent was immobilized into magnesium-aluminum LDH in order to improve the drug efficiency as well as to achieve the controlled release property. BBC molecules were immobilized into MgAl LDH through a conventional ion exchange reaction and co-precipitation method. The ion-exchange experiments of BBC on MgAl LDH were investigated with particular attention paid to the influence of the layer charge, the nature of the intercalated anion and the morphology. The immobilization efficiency was dependent upon the LDH properties and the immobilization process. Characterization by powder x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and contact angle measurements revealed that the interaction of BBC with MgAl LDH occurs by adsorption rather than intercalation of BBC within LDH layers. In vitro anti-bacterial tests were carried out using disc diffusion assay to prove the effectiveness of these novel biohybrid beads as a controlled drug delivery method. Consequently, the BBC-LDH co-precipitated formulation revealed an enhanced anti-bacterial activity compared to the ion-exchanged formulation not only due to an improvement of chemical stability and retained amount of BBC molecules but also due to the release property.

The effect of the Thymus vulgaris extracts on the physicochemical characteristics of cedar wood using angle contact measurement

The aim of the study was to investigate the effect of crude extracts of Thymus vulgaris on wood surface physicochemical characteristics. Thus, the Lifshitz-van der Waals (), acid–base (surface tension components ΔGiwi, electron donor () and electron acceptor () parameters of untreated and treated wood were assessed using contact angle measurement. The main results showed that all T. vulgaris extracts are able to change wood surface properties. Indeed, the samples treated with the product obtained by maceration and ultrasound indicated the hydrophilic character (θw = 29.7 ± 0.3°, ΔGiwi = 17. 78 ± 0.48 mJ/m2 and θw = 18.2 ± 0.2°, ΔGiwi = 30.62 ± 0.31 mJ/m2) respectively, and had less contact angle values than that of untreated wood (θw = 86.0 ± 0.2°). In addition, this treatment has made the wood more donor ( = 44.76 ± 0.3 mJ/m2 and  = 53.80 ± 0.3 mJ/m2) than the electron acceptor compared to sample control ( = 2.03 ± 0.04 mJ/m2). Finally, the effect of the extract obtained by ultrasound was found to be more important and significant than those recovered by classical extraction.

Delivery system for berberine chloride based on the nanocarrier ZnAl-layered double hydroxide: Physicochemical characterization, release behavior and evaluation of anti-bacterial potential

Layered double hydroxide (LDH) has attracted major interest as one of the most versatile drug delivery systems especially for adsorption capacity and/or controlled delivery property of bioactive agents owing to their combining features of biohybrid. ZnAl synthesized layered double hydroxide can offer a platform to immobilize various types of bioactive compounds, particularly berberine chloride (BBC). However, the immobilization reaction of berberine chloride into ZnAl-LDH was performed by direct co-precipitation method at different ratios of BBC/LDH. BBC-ZnAl-LDH biohybrids were characterized in terms of structure, surface morphology, in vitro drug release profile and antibacterial assay against various bacterial cells. The BBC biomolecules were attached by coordinate bond. Structural and microstructural characterization confirms that interaction of BBC with ZnAl-LDH occurs by adsorption rather than intercalation of BBC within LDH layers. The BBC release profiles from BBC-ZnAl-LDH had a longer release duration compared to the physical mixture, and the drug release seemed faster with the low ratio of BBC/LDH. BBC-ZnAl-LDH can be internalized into bacterial cells. In vitro experiments in PBS medium showed that BBC-ZnAl-LDH biohybrid had higher cytotoxicity and inhibitory effects against three pathogenic bacteria; Staphylococcus aureus CIP 543154, Pseudomonas aeruginosa A22 and Bacillus subtilus ILP 1428B upon the drug release profiles and its destructive potential depends on the loading BBC on the LDH layers. Nonetheless these results prove that the prepared BBC-ZnAl-LDH biohybrids retain the anti-bacterial character of the BBC molecules and are therefore potential modified drug delivery system (DDS).

Determination of endoglucanase activity of paper decaying fungi from an old library at the ancient Medina of Fez

Paper from an ancient library of the cultural city of Fez (Morocco) is exposed to rapid deterioration by variety of microorganisms, especially cellulolytic fungi. For this, ten isolates fungi previously isolated from historical biodeteriorated paper were screened for their ability to produce endoglucanase (CMCase), amylase, polygalacturonase and ligninase enzymes. The CMCase activity of cellulolytic strains was essayed in liquid media at 25°C for 10 days. Influence of temperature and pH were assessed for the production of CMCase by all the fungus isolated from decaying paper. The research findings from the present study demonstrate that all the tested isolates had cellulase, amylase, pectinase and ligninase activities. It was found that Mucor racemosus PF15, Aspergillus niger, and Aspergillus oryzae exhibited the maximum endoglucanase activity in liquid medium (0.256, 0.236, and 0.216 UI/mL in descending order) for six days. Temperature profiling revealed optimum endoglucanase activity at 25 and 30°C. Maximum activity was observed at pH 5 and pH 6.

Physicochemical characterization of actinomycetes isolated from decayed cedar wood: contact angle measurement

Physicochemical characterization of microorganism is very important in a wide range of scientific and technological fields. In this study, we reported the isolation and the molecular identification of actinomycetes recovered from cedar wood decay. The isolates named H5 and H8 were identified by 16S rDNA sequencing and were shown to belong to the genus Nocardia and Streptomyces, respectively. Furthermore, physicochemical proprieties including hydrophobicity, electron donor/acceptor, and the Lifshitz–van der Waals (γLW) of these strains were evaluated using contact angle measurements. The results showed that Nocardia sp. (H5) had a hydrophobic (ΔGiwi = −78.56 mJ/m2) and a weak electron donor/acceptor character. In contrast, results from contact angle measurements showed that the surface free energy of Streptomyces strains (H2, H3, and H8) were ΔGiwi = 20.71 mJ/m2, ΔGiwi = 30.63 mJ/m2, and ΔGiwi = 15.35 mJ/m2, respectively, classifying these microorganisms as hydrophilic bacterium. Moreover, the three strains were predominantly electron donating (γ– ) and exhibit a weak electron-accepting (γ+) character.

Chemical characterization and antimicrobial activity of Moroccan Pelargonium asperum essential oil

ABSTRACT In the aim of valorizing aromatic and medicinal plants from Morocco, this work focuses on the chemical characterization and antimicrobial activity of Pelargonium asperum essential oil against 11 microbial strains causing problems in the medical and food domain. The chemical profile of the volatile oil was investigated by GC/MS. The major compounds were citronellol (26.98%), geraniol (14.12%), isomenthone (8.80%), linalool (4.97%), citronellyl formate (3.1%), followed by geranyl formate (4.07%) and guai-6,9-diene (4.24%). The results of antimicrobial activity by using the broth microdilution method indicated that essential oil of Pelargonium asperum exhibited significant antimicrobial activity against all tested microorganisms with the strongest inhibitory effect against yeasts. The MICs values ranged from 0.003% to 0.25% (v/v) for all strains, except Pseudomonas aeruginosa, which was least susceptible and inhibited by 2% (v/v). These results suggest that Pelargonium asperum oil could be used for the development of new antimicrobial agents.