Diffusion of biological molecules through hollow chitosan fibers

Abstract

Hollow chitosan fibers were tested for the diffusion of a series of biological macromolecules, including amino acids, vitamins, and antibiotics. The hollow fibers were immersed in the permeant solution, and water was circulated and recycled inside the lumen of the fiber. The concentration of the permeant in the hollow fiber loop was analyzed online by ultraviolet-visible spectrophotometry. The effect of process parameters such as the concentration, pH, and flow rate was tested. The permeability coefficient was calculated from the permeability. The limited influence of the flow rate indicated that resistance to film diffusion (at the surface of the fiber) was not the ratelimiting step: the limiting step remained diffusion through the membrane. The pH would be expected to influence the protonation of chitosan amine groups and the acidbase properties of the permeant; however, the diffusion profiles were little affected by this parameter. The impact of pH on the permeability coefficient decreased in the following order: tryptophan > chloramphenicol > vitamin B12. The change in the concentration of the permeant had a limited impact on the permeability coefficient.

Solvent-Dependent Cage Dynamics of Small Nonpolar Radicals: Lessons from the Photodissociation and Geminate Recombination of Alkylcobalamins

“…This is consistent with the radius estimated from the calculated molar volume using the LeBas correction . The hydrodynamic radius of vitamin B 12 has also been estimated at 8.5 Å from diffusion measurements assuming a spherical molecule, , thus 7.1 Å should be considered a lower limit. The reactive radius is taken to be the sum of these R = 11.2 Å.…”

Palladium and platinum sorption using chitosan-based hydrogels

“…Indeed, polymer solubilization is a necessary step that allows further preparing chitosan hydrogels in the form of spherical particles (Lee et al 2001), films, membranes (Vieira et al 2007), fibers and even hollow fibers (Peirano et al 2008;Vincent and Guibal 2000). The process generally consists in extruding the viscous solution of chitosan into a coagulation or neutralization bath (NaOH, tripolyphosphate).…”

Hollow Chitosan Fibers

“…pH of the permeant was found to have the most significant impact on permeability with the permeability coefficient decreasing with the molecular weight of the permeant. These fibers were considered suitable for catalysis and support for biological molecules or enzymes or for controlled drug release and enzyme immobilization [08Pei]. Hollow chitosan/cellulose acetate fibers were produced by wet spinning for use as absorptive membranes for affinity-based separations [05Liu].…”