Biologically active ionic chitosan Schiff base nanocomposites: Synthesis, characterization and antimicrobial activity against Helicobacter pylori.

1-(2-((4-Bromophenyl)amino)-2-oxoethyl)pyridin-1-ium chloride Schiff base (CH-Py) was prepared via reacting (CH) with pyridine-3-carboxaldehyde, followed by reacting the product with N-(4-bromophenyl)-2-chloroacetamide. The structure of the resulting CH derivative was determined viaHNMR and FTIR. The CH-Py derivative was converted into nanoparticles (CH-Py-Cl NPs) using sodium tripolyphosphate (TPP).

Synthesis of novel chitosan-Schiff bases nanoparticles for high efficiency Helicobacter pylori inhibition.

Two chitosan Schiff bases were synthesized by condensation of chitosan with 2-(4-formylphenoxy)-N-phenylacetamide and N-(4-bromophenyl)-2-(4-formylphenoxy) acetamide denoted as Cs-SBA and Cs-SBBr, respectively. The molecular structures of the resulting chitosan derivatives were characterized using FTIR and HNMR and their thermal properties were investigated by TGA. These derivatives were treated with sodium tripolyphosphate (TPP) to produce Cs Schiff base nanoparticles.

Synthesis and biological evaluation against H. pylori of chitosan menthone Schiff base hybrid with different types of inorganic nanoparticles.

The production of novel natural medicines for the treatment of Helicobacter pylori (H. pylori) has lately attracted a lot of interest. Some bacterial infections have traditionally been alleviated by terpenes.

Synthesis and characterization of poly(3-hydroxybutyrate)/chitosan-graft poly (acrylic acid) conjugate hyaluronate for targeted delivery of methotrexate drug to colon cancer cells.

Anti-cancer medications that are delivered specifically to the tumor site possess greater efficacy with less negative effects on the body. So, the current research relies on a novel method for intercalating the anticancer medication methotrexate in poly(3-hydroxybutyrate)/chitosan-graft poly (acrylic acid) conjugated with sodium hyaluronate. The graft copolymers were synthesized through persulfate-initiated grafting of acrylic acid onto a binary mixture of various amounts of chitosan and poly(3-hydroxybutyrate) (2/1, 1/1 and 1/2, w/w) using microwave irradiation.

Synthesis and characterization of hydrogel-based magnetite nanocomposite adsorbents for the potential removal of Acid Orange 10 dye and Cr(VI) ions from aqueous solution.

Magnetic responsive hydrogels (CMX-cl-P4VP/M-NPs) were successfully synthesized through in situ co-precipitation procedure and investigated using various techniques. The surface morphology analysis revealed that the M-NPs were uniformly distributed within the hydrogel matrix and had average sizes ranging from 4.98 to 15.

An effective uranium removal using diversified synthesized cross-linked chitosan bis-aldehyde Schiff base derivatives from aqueous solutions.

Three new cross-linked chitosan derivatives were yielded through intensification of chitosan with diverse types of bis-aldehydes. The prepared cross-linked chitosan was characterized by FTIR, H NMR, XRD, and TGA techniques. TGA indicated an improvement in thermal stability of the cross-linked chitosan compared with pure chitosan.

Study of Ag Nanoparticles in a Polyacrylamide Hydrogel Dosimeters by Optical Technique.

The dosimetric characteristics of hydrogel dosimeters based on polyacrylamide (PAC) as a capping agent incorporating silver nitrate as a radiation-sensitive material are investigated using UV-Vis spectrophotometry within the dose range 0-100 Gy. Glycerol was used in the hydrogel matrix to promote the dosimetric response and increase the radiation sensitivity. Upon exposing the PAC hydrogel to γ-ray, it exhibits a Surface Plasmon Resonance (SPR) band at 453 nm, and its intensity increases linearly with absorbed doses up to 100 Gy.

Chitosan Schiff bases-based polyelectrolyte complexes with graphene quantum dots and their prospective biomedical applications.

Chitosan (Cs) bis-aldehyde Schiff base derivatives were synthesized by condensation of Cs with three bis-aldehydes namely; butane-1,4-diyl bis(4-formylbenzoate), N,N'-(butane-1,4-diyl)bis(2-(4-formylphenoxy)acetamide) and 4,4'-(butane-1,4-diylbis(oxy))dibenzaldehyde. The prepared Cs derivatives were blended with carboxymethyl chitosan(CMC) and graphene quantum dots (GQDs) to produce semi-IPNs polyelectrolyte complexes (PECs). and characterized with respect to their molecular structure and physio-chemical properties.

Nanocurcumin: preparation, characterization and cytotoxic effects towards human laryngeal cancer cells.

The aim of the present study was to prepare curcumin nanoparticles (nanocurcumin) by a sol-oil method to improve curcumin absorption and bioavailability, and to investigate the therapeutic effects of the prepared nanoparticles on the inhibition mechanisms towards human Hep-2 cancer cells. The nanoparticles were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, and zeta potential analysis. The prepared curcumin nanoparticles possessed a narrow particle size distribution with an average diameter of 28 nm.

Synthesis, characterization and antimicrobial activity of a novel chitosan Schiff bases based on heterocyclic moieties.

Three heteroaryl pyrazole derivatives; namely 1-phenyl-3-(thiophene-2-yl)-1H-pyrazole-4-carbaldehyde, 1-phenyl-3-(furan-2-yl)-1H-pyrazole-4-carbaldehyde and 1-phenyl-3-(pyridine-3-yl)-1H-pyrazole-4-carbaldehyde were synthesized and reacted with chitosan to form Schiff bases of chitosan. All newly synthesized compounds have been characterized by solubility tests, elemental analysis, spectral (FTIR, H NMR) analyses, thermogravimetric analysis and X-ray diffraction (XRD). The Schiff bases were screened for their biological activity against gram-negative bacteria (Escherichia coli and Klebsiella pneumonia), gram-positive bacteria (Staphylococcus aureus and Streptococcus mutans) and fungi (Asperagillus fumigatus and Candida albican).

Comparative evaluation for controlling release of niacin from protein- and cellulose-chitosan based hydrogels.

This work deals with assessing the efficient performance of sodium caseinate (SC) as protein-based drug delivery system of niacin (NA) than carboxymethyl cellulose (CMC). In this respect the hydrogels from complexation of chitosan with sodium caseinate (SC/Ch) or sodium carboxymethyl cellulose (CMC/Ch) were prepared. The Synthesized NA free and loaded hydrogels were characterized by many techniques for examining the interaction, morphology, swelling, encapsulation efficiency (EE) and loading (L) % of niacin, as well as cytotoxicity study.

Grafting of multiwalled carbon nanotubes with pyrazole derivatives: characterization, antimicrobial activity and molecular docking study.

Introduction: It is well known that the grafted multiwalled carbon nanotubes (MWCNTs) have antibacterial activity and lower cytotoxicity. Moreover, pyrazole derivatives have a broad spectrum of biological activity due to their fertile template for many medicinal drugs. On view of these findings we report herein the hybridization between MWCNTs and some pyrazole derivatives as antibacterial agents.

Encapsulation of ciprofloxacin within modified xanthan gum- chitosan based hydrogel for drug delivery.

The aim of the present work was to investigate the preparation of polyelectrolyte hydrogel as potential drug carrier for antibacterial Ciprofloxacin drug (CFX), intended for controlled release formulation. Hydrogel of N-trimehtyl chitosan (TMC)/sodium carboxymethyl xanthan gum (CMXG) was prepared and ciprofloxacin was employed as a model drug to investigate the loading and release performance of the prepared hydrogel. FTIR, DSC, TGA and SEM analysis were used to characterize the TMC/CMXG hydrogel and its CFX loaded hydrogel.

Thermal properties, crystallization and antimicrobial activity of chitosan biguanidine grafted poly(3-hydroxybutyrate) containing silver nanoparticles.

Green synthesis of novel nanocomposites series based on chitosan biguanidine grafted poly(3-hydroxybutyrate) copolymer (ChG-g-PHB) and silver nanoparticles (AgNPs) was successfully done via in situ reduction of AgNO in the copolymer matrix. Transmission electron microscopy verified the homogeneous dispersion of spherical shape of the AgNPs with an average particle size 12.3 to 19.

Synthesis, characterization and antimicrobial activity of biguanidinylated chitosan-g-poly[(R)-3-hydroxybutyrate].

Chitosan biguanidine hydrochloride (ChG) and low molecular weight poly[(R)-3-hydroxybutyrate] (PHB) were successfully prepared to overcome the solubility problem of chitosan and PHB and also to enhance antimicrobial activity of chitosan. The graft copolymers based on ChG and PHB (ChG-grafted PHB) were then prepared via condensation reaction of the carboxylic groups of PHB with the amino groups of ChG. These graft copolymers swell in water.

Synthesis, characterization, and biological activity of cross-linked chitosan biguanidine loaded with silver nanoparticles.

Chitosan biguanidine hydrochloride (ChG) and glutaraldehyde cross-linked chitosan biguanidine (CChG) were synthesized and characterized by Fourier transform infrared spectroscopy, H NMR and C NMR, X-ray diffraction, scanning electron microscopy (SEM) and thermal analyses (TGA and DTA). The results showed that ChG and CChG had a more amorphous structure than that of chitosan, and their thermal stability were slightly lower than that of chitosan. Colloidal silver nanoparticles (AgNPs) were prepared using borohydride reduction method and then investigated as fillers in partially cross-linked chitosan biguanidine.

Isolation and characterization of chitosan from different local insects in Egypt.

Chitin was extracted from four different local sources: the shrimp (Penaeus monodon), the desert locust (Schistocerca gregaria), the honey bee (Apis mellifera) and the beetles (Calosoma rugosa). Chitosan was then obtained by deacetylation of chitin and physicochemically characterized using the Fourier transform infrared (FTIR) and X-ray diffraction. The moisture content, water binding capacity, fats binding capacity, ash content were determined and chitosans morphology was visualized using the scanning electron microscope (SEM).

Synthesis, characterization and biological activity of Schiff bases based on chitosan and arylpyrazole moiety.

The Schiff bases of chitosan were synthesized by the reaction of chitosan with 3-(4-substituted-phenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde. The structure of the prepared chitosan derivatives was characterized by FT-IR spectroscopy, elemental analysis, and X-ray diffraction studies and thermogravimetric analysis (TG). The results show that the specific properties of Schiff bases of chitosan can be altered by modifying the molecular structures with proper substituent groups.