M.R. El-Aassar

Antimicrobial activity of carboxymethyl chitosan/polyethylene oxide nanofibers embedded silver nanoparticles

A facile method to synthesize silver nanoparticles (AgNPs) using carboxymethyl chitosan (CMCTS), which act as reducing agent for silver ions as well as protecting agent for the formed AgNPs, is reported. CMCTS embedded AgNPs are mixed with polyethylene oxide (PEO). The blend polymers containing AgNPs are electrospun resulting in blend nano-fiber mats. The formation of AgNPs has been confirmed using UV-vis and TEM. The diameter range of 12-18 nm of well-dispersed AgNPs with a concentration of 100 ppm was obtained. The electrospun mats are characterized using SEM, EDX as well as TGA. Antimicrobial activity against different species of pathogenic/nonpathogenic; Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922 in addition to the fungus Candida albicans ATCC 10231 was studied. The results show excellent antimicrobial activity compared with nanofibers without AgNPs and AgNPs alone.

Affinity Covalent Immobilization of Glucoamylase onto ρ-Benzoquinone Activated Alginate Beads: I. Beads Preparation and Characterization

Abstractρ-Benzoquinone-activated alginate beads were presented as a new carrier for affinity covalent immobilization of glucoamylase enzyme. Evidences of alginate modification were extracted from FT-IR and thermal gravimetric analysis and supported by morphological changes recognized through SEM examination. Factors affecting the modification process such as ρ-benzoquinone (PBQ) concentration, reaction time, reaction temperature, reaction pH and finally alginate concentration, have been studied. Its influence on the amount of coupled PBQ was consequently correlated to the changes of the catalytic activity and the retained activity of immobilized enzyme, the main parameters judging the success of the immobilization process. The immobilized glucoamylase was found kept almost 80% of its native activity giving proof of non-significant substrate, starch, diffusion limitation. The proposed affinity covalent immobilizing technique would rank among the potential strategies for efficient immobilization of glucoamylase enzyme.

Microencapsulation of lectin anti-cancer agent and controlled release by alginate beads, biosafety approach.

Hepatocellular carcinoma (HCC) is considered as one of the most aggressive cancer worldwide. In Egypt, the prevalence of HCC is increasing during last years. Recently, drug-loaded microparticles were used to improve the efficiency of various medical treatments. This study is designed to evaluate the anticancer potentialities of lectins against HCC while hinting to its safety usage. The aim is also extended to encapsulate lectins in alginate microbeads for oral drug delivery purposes. The extracted lectins showed anti-proliferative effect against HCC with a percentage of 60.76% by using its nontoxic dose with an up-regulation of P53 gene expression. Concerning the handling of lectin alginate microbeads for oral drug delivery, the prepared lectin alginate beads were ∼100μm in diameter. The efficiency of the microcapsules was checked by scanning electron microscopy, the SEM showed the change on the alginate beads surface revealing the successful lectin encapsulation. The release of lectins from the microbeads depended on a variety of factors as the microbeads forming carriers and the amount-encapsulated lectins. The Pisum sativum extracted lectins may be considered as a promising agent in controlling HCC and this solid dosage form could be suitable for oral administration complemented with/or without the standard HCC drugs.

k-Carrageenan/poly vinyl pyrollidone/polyethylene glycol/silver nanoparticles film for biomedical application

Biopolymer composite film containing k-carrageenan (KC), polyvinyl pyrrolidone (PVP), and polyethylene glycol (PEG) was formulated by dissolving KC and PVP in water containing PEG. Silver nanoparticles (AgNPs), was produced by Honeybee and added to solution. Finally, all solutions were poured onto dishes and dried overnight at 40°C to form the final films. Tensile strength (TS) and elongation (E %) is evaluated. The water contact angle is inspected. Thermal properties (TGA) and swelling behavior for water were considered. Fungal activity is also examined. Morphology of all films was also explored using scanning electron microscope. AgNPs induced significant hydrophilicity to KC-PVP-PEG film with contact angle of 41.6 and 34.7 for KC-PVP-PEG-AgNPs. Films with AgNPs exhibited higher thermal stability and strength properties than other films without. Films with AgNPs explore lower swelling behavior than other films without. Both SEM and EDX proved the deposition of AgNPs on the surface of films. Films with AgNPs showed higher activity against pathogenic fungi compared with the chemical fungicide; fluconazole.

Controlled drug release from cross-linked κ-carrageenan/hyaluronic acid membranes

In this work, hydrogel membrane composed of; kappa carrageenan (κC) and hyaluronic acid (HA) crosslinked with epichlorohydrine is produced. The optimum condition has been established based on their water absorption properties. Tensile strength (TS) and elongation (E%) for the formed films are evaluated. The obtained films were characterized by FTIR, scanning electron microscopy (SEM) and thermal analysis. All membranes were loaded with l-carnosine as a drug model. The swelling properties and kinetics of the release of the model drug from the crosslinked hydrogel membrane were monitored in buffer medium at 37°C. The equilibrium swelling of films showed fair dependency on the high presence of HA in the hydrogel. Moreover, the cumulative release profile increased significantly and ranged from 28% to 93%, as HA increases. SEM explored that, the porosity increased by increasing HA content; consequently, drug release into the pores and channels of the membranes is facilitated. In addition, water uptake % increased as well. A slight change in TS occurred by increasing the HA% to κC, while the highest value of strain for κC membrane was 498.38% by using 3% HA. The thermal stability of the κC/HA was higher than that of HA.

Adsorption Profile of Basic Dye onto Novel Fabricated Carboxylated Functionalized Co-Polymer Nanofibers

Acrylonitrile-Styrene co-polymer was prepared by solution polymerization and fabricated into nanofibers using the electrospinning technique. The nanofiber polarization was enhanced through its surface functionalization with carboxylic acid groups by simple chemical modification. The carboxylic groups’ presence was dedicated using the FT-IR technique. SEM showed that the nanofiber attains a uniform and porous structure. The equilibrium and kinetic behaviors of basic violet 14 dye sorption onto the nanofibers were examined. Both Langmuir and Temkin models are capable of expressing the dye sorption process at equilibrium. The intraparticle diffusion and Boyd kinetic models specified that the intraparticle diffusion step was the main decolorization rate controlling the process.

Preparation and characterization of imino diacetic acid functionalized alginate beads for removal of contaminants from waste water: I. methylene blue cationic dye model

Abstract This study deals with the development of a clean and safe process for water pollution remediation. We studied the potential use of Imino Diacetic Acid (IDA) activated calcium alginate beads for removal of cationic dyes from colored effluents in dynamic batch mode. Methylene blue (MB) has been chosen as a dye model for the study. The parameters that affect the beads surface modification process such as ρ-benzoquinone (PBQ) and IDA concentration, reaction time, pH, temperature and finally cross linking time in calcium chloride solution were studied. Maximum percents of dye removal are about 65% and 90% were achieved at initial MB concentration of 50 mg l−1 after 60 min of adsorption at temperature (22 ± 1°C) for calcium alginate and IDA activated calcium alginate beads respectively. Surface modification reduces the competitive action of calcium ions especially at high bead’s crosslinking degree. Removal percentage was doubled using modified alginate beads cross linked for 120 min at 2% CaCl2. In co...

Synthesis, Characterization, and Antimicrobial Activity of Poly(acrylonitrile-co-methyl methacrylate) with Silver Nanoparticles

Nanotechnology is expected to open some new aspects to fight and prevent diseases using atomic-scale tailoring of materials. The main aim of this study is to biosynthesize silver nanoparticles (AgNPs) using Trichoderma viride (HQ438699); the metabolite of this fungus will help either in reduction of the silver nitrate-adding active materials which will be loaded on the surface of the produced AgNPs. Poly(acrylonitrile-co-methyl methacrylate) copolymer (poly (AN-co-MMA)) was grafted with the prepared AgNPs. The poly(AN-co-MMA)/AgNPs were examined against ten different pathogenic bacterial strains, and the result was compared with another four different generic antibiotics. The produced poly(AN-co-MMA)/AgNPs showed high antibacterial activity compared with the four standard antibiotics. Moreover, the grafting of these AgNPs into the copolymer has potential application in the biomedical field.

Poly (acrylonitrile-co-methyl methacrylate) nanofibers grafted with bio-nanosilver particles as antimicrobial against multidrug resistant bacteria

1 City of Scientific Research and Technology Applications, Arid Lands Cultivation Research Institute (ALCRI),Molecular Plant Pathology Department, New Borg El Arab City, 21934, Alexandria, Egypt. 2 Department of Chemistry, Petrochemical Research Chair, King Saud University, P.O. Box: 2455 Riyadh 11451, Riyadh, Kingdom Of Saudi Arabia. 3 Department of Polymer Materials Research Advanced Technologies And New Material Research Institute, City for Scientic Research And Technology Applications (MuCSAT), New Borg El-Arab City 21934 Alexandria, Egypt Alexandria, Egypt. 4 Department of Mechanical Engineering, King Saud University, Riyadh 11421, Saudi Arabia. 5 Department of Biology, Faculty of Science, King Khalid University, Abha, Saudi Arabia.

Rhizofiltration system consists of chitosan and natural Arundo donax L. for removal of basic red dye

Arundo donax L. (A. donax) plant, which are naturally grown, is capable of removing heavy metals, toxins and dyes from the environment. In addition the cell structure A. donax enable the whole to make phytoremdation for the most of environmental pollutions. For that reasons, the A. donax cells were obtained and dispersed in polymer compost to form what is called bio-chemical/dye removing system. In details; Polymeric beads were fabricated from natural low cost materials of chitosan (Cs), A. donax (cells), gelatin (GP) and poly vinyl pyrrolidone (PVP) to be applied as a powerful sorbent for CI Basic Red 14 dye. The morphological structure of the fabricated beads was investigated by Scanning Electron Microscope (SEM) and the results revealed that most immobilized A. donax cells into beads and micro-clusters are formed inside the beads. The effect of experimental variables such as sorbent dose, initial dye concentration, pH, and contact time were investigated. Freundlich and Langmuir isotherm models were applied to describe sorbent-dye sorption system. Equilibrium isotherms of CI Basic Red 14 dye on the fabricated beads were obtained, where the first-order rate model is more appropriate.