Dithiocarbamate chitosan, an insoluble derivative obtained from carbon disulfide, and N-(o—carboxybenzyl) chitosan and N—car— boxymethyl chitosan, two water—soluble olyamoholytes obtained from phthalaldehydic acid and glyoxylic acid, can be used for removal of metal ions from dilute solutions. Their characteristic properties are described in terms of infrared, ultraviolet and circular dichroism...

Designing scaffolds made from natural polymers may be highly attractive for tissue engineering strategies. We sought to produce and characterize chitosan-coated collagen membranes and to assess their efficacy in promoting chondrocyte adhesion, growth, and cytokine secretion. Porous collagen membranes were placed in chitosan solutions then crosslinked with glutaraldehyde vapor. Fourier transform...

entrapment of permeabilized whole cells within a matrix is a common method for immobilization. chitosan possesses distinct chemical and biological properties, which make it a suitable matrix for entrapment and immobilization of penicillin g acylase (pga). in the first step, escherichia coli (atcc 11105) cells were permeabilized using n-cetyl-n,n,n-trimethyl ammonium bromide (ctab) (0.1% w/v, 45...

The synthesis of two biocatalysts based on a commercial Candida antarctica lipase B, CALB enzyme (E), physically immobilized silica supports, was carried out. first support periodic mesoporous organosilica (PMO) and the second one modified with octyl groups (octyl-MS3030). maximum load 122 mg enzyme/g PMO 288 octyl-MS3030. In addition, biocatalytic efficiency corroborated by reaction tests hydr...

Bacterial flagellar motors use specific ion gradients to drive their rotation. It has been suggested that the electrostatic interactions between charged residues of the stator and rotor proteins are important for rotation in Escherichia coli. Mutational studies have indicated that the Na(+)-driven motor of Vibrio alginolyticus may incorporate interactions similar to those of the E. coli motor, ...

The polar flagellar motor of Vibrio alginolyticus rotates using Na(+) influx through the stator, which is composed of 2 subunits, PomA and PomB. About a dozen stators dynamically assemble around the rotor, depending on the Na(+) concentration in the surrounding environment. The motor torque is generated by the interaction between the cytoplasmic domain of PomA and the C-terminal region of FliG,...

The interaction of chitosan with plasmid DNA was investigated as a function of pH, buffer composition, degree of deacetylation (DDA), and molecular weight (M(n)) of chitosan, using isothermal titration microcalorimetry (ITC). The Single Set of Identical Sites model was used to obtain the enthalpy of interaction, the binding constant, and the stoichiometry of binding. The chitosan-DNA interactio...

Natural and biodegradable chitosan with unique amino groups has found widespread applications in tissue engineering and drug delivery. However, its applications have been limited by the poor solubility of native chitosan in neutral pH solution, which subsequently fails to achieve cell-laden hydrogel at physiological pH. To address this, we incorporated UV crosslinking ability in chitosan, allow...