The mode of antimicrobial action of chitosan (polymeric beta-1,4-N-acetylglucosamine) on gram-negative bacteria was studied with special emphasis on its ability to bind to and weaken the barrier function of the outer membrane (OM). Chitosan (250 ppm) at pH 5.3 induced significant uptake of the hydrophobic probe 1-N-phenylnaphthylamine (NPN) in Escherichia coli, Pseudomonas aeruginosa and Salmon...

Chitosan is a cationic polysaccharide with great properties and so is considered as an attractive biopolymer. However, chitosan shows its antibacterial activity only in acidic environment and this restricts its uses. So water-soluble chitosan derivatives such as carboxymethyl chitosan could be good candidates for such biomedical applications. Modified chitosan with hydrophobic functional groups...

The aggregation phenomena in aqueous solutions of hydrophobically modified (HM) chitosan, containing 4 mol % of n-dodecyl side chains, were studied by viscometry and fluorescence spectroscopy with pyrene as a probe. The results are compared with those for unmodified chitosan. Surprisingly, fluorescence data reveal the appearance of intermolecular hydrophobic aggregates both in chitosan and in H...

Osteoblast maturation plays a key role in regulating osteogenesis. Electrospun nanofibrous products were reported to possess a high surface area and porosity. In this study, we developed chitosan nanofibers and examined the effects of nanofibrous scaffolds on osteoblast maturation and the possible mechanisms. Macro- and micro observations of the chitosan nanofibers revealed that these nanoprodu...

The focus of this review is to provide an overview of the chitosan based nanoparticles for various non-parenteral applications and also to put a spotlight on current research including sustained release and mucoadhesive chitosan dosage forms. Chitosan is a biodegradable, biocompatible polymer regarded as safe for human dietary use and approved for wound dressing applications. Chitosan has been ...

It was the aim of this study to determine the potential of two aliphatic and two aromatic thiolated chitosan conjugates: chitosan-thioglycolic acid (chitosan-TGA), chitosan-4-thiobutylamidine (chitosan-TBA), chitosan-6mercaptonicotinic acid (chitosan-6MNA) and chitosan-4-mercaptobenzoic acid (chitosan-4MBA), respectively, as permeation enhancing agents. Ritonavir was employed as model compound....

The low transfection efficiency of chitosan is one of its drawbacks as a gene delivery carrier. Low molecular weight chitosan may help to form small-sized polymer-DNA or small interfering RNA (siRNA) complexes. Folate conjugation may improve gene transfection efficiency because of the promoted uptake of folate receptor-bearing cells. In the present study, chitosan was conjugated with folate and...

Chitin is a biopolymer. Theoretically, it is a homopolymer of acetyl-glucosamine. Chitosan is the deacetylated product of chitin. Chitin and chitosan have many applications in water purification, agriculture, food and pharmaceutical industries. Currently, industrial production for chitin and chitosan is from the shell wastes. The objective of this study was to evaluate the feasibility of chitin...

Polyelectrolyte hydrogels formed by xanthan gum and chitosan can be used for encapsulation and controlled release of food ingredients, cells, enzymes, and therapeutic agents. In this study, xanthan–chitosan microcapsules were formed by complex coacervation. The effects of initial polymer concentration and chitosan solution pH on the crosslinking density of xanthan–chitosan network were investig...