PURPOSE The aim of this study was to make 5-aminolevulinic acid (5-ALA)-incorporated nanoparticles using methoxy polyethylene glycol/chitosan (PEG-Chito) copolymer for application in photodynamic therapy for colon cancer cells. METHODS 5-ALA-incorporated (PEG-Chito-5-ALA) nanoparticles were prepared by ion complex formation between 5-ALA and chitosan. Protoporphyrin IX accumulation in the tum...

BACKGROUND Most of the current colorimetric methods for detection of chitinase or cellulase activities on the insoluble natural polymers chitin and cellulose depend on a chemical redox reaction. The reaction involves the reducing ends of the hydrolytic products. The Schales' procedure and the 3,5-dinitrosalicylic acid (DNS) method are two examples that are commonly used. However, these methods ...

Papain (from papaya latex; EC 3.4.22.2) and Pronase (from Streptomyces griseus; EC 3.4.24.31) caused optimum depolymerization of chitosan at pH 3.5 and 37 degrees C, resulting in LMMC (low molecular mass chitosan) and chito-oligomeric-monomeric mixture. The yield of the latter was 14-16% and 14-19% respectively for papain- and Pronase-catalysed reactions, depending on the reaction time (1-5 h)....

chitosan (chito) as a biopolymer with high antibacterial, biocompatibility and biodegradability and polyaniline (pani) as a conductive polymer and silver (ag) nanoparticles to enhance antibacterial property were used to prepare polyanilin-chitosan-silver (pani-chito-ag) nanocomposites. the synthesis of panichito composite and pani-chito-ag nanocomposite was performed through aniline polymerizat...

An increasing interest has recently been shown to use chitin/chitosan oligomers (chito-oligomers) in medicine and food fields because they are not only water-soluble, nontoxic, and biocompatible materials, but they also exhibit numerous biological properties, including antibacterial, antifungal, and antitumor activities, as well as immuno-enhancing effects on animals. Conventional depolymerizat...

In this study, a new modified chitosan conjugate (Chito-TZ) was developed via amide coupling between the acid chloride derivative of methylthio-thidiazole compound and free primary amino groups chitosan. The product characterized using several instrumental investigations, including Fourier-transform infrared spectroscopy (FT-IR), 1H-Nuclear magnetic resonance, X-ray photoelectron (XPS), thermog...

The effects of carbohydrates on the toxicity of p-Aminophenyl arsenoxide (p-APAO) against S. cerevisiae were investigated by Microcalorimetry, including glucose, fructose, lactose, sucrose, N-acetyl glucosamine, 1,3,4,6-tetra-O-acetyl-D-glucosamine (OADG), and chito-oligomer. The toxicity of p-APAO on S. cerevisiae decreased in the presence of OADG or chito-oligomer. Among the test carbohydrate...

Chitin is a major component of fungal walls and insect exoskeletons. Plants produce chitinases upon pathogen attack and chito-oligomers induce defense responses in plants, though the exact mechanism behind this response is unknown. Using the ATH1 Affymetrix microarrays consisting of about 23,000 genes, we examined the response of Arabidopsis (Arabidopsis thaliana) seedlings to chito-octamers an...

A lectin specific for chito-oligosaccharides from the exudate of ridge gourd (Luffa acutangula) fruits has been purified to homogeneity by affinity chromatography. The lectin has a molecular weight of 48,000, an S(0)20,w of 4.06 S and a Stokes radius of 2.9 nm. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis, a single band corresponding to Mr of 24,000 was observed both in the pr...