Chitosan-phenylalanine-mPEG nanoparticles: From a single step water-based conjugation to the potential allergen delivery system.

The chemical modification to obtain biocompatible chitosan (CS) nanoparticles for the application in biological system is still on expectation. By simply mixing CS with hydroxybenzotriazole (HOBt), the CS aqueous solution obtained allows a successful single step conjugation of both hydrophobic biomolecules, i.e.

Rapid hybridization of chitosan-gold-antibodies via metal-free click in water-based systems: a model approach for naked-eye detectable antigen sensors.

A surface plasmon resonance (SPR) expression after hybridization of chitosan-gold nanoparticle-antibody (CS-AuNPs-Ab) based on: i) metal-free click chemistry, and, ii) in water system as an approach for a rapid antigen sensing, is proposed. The chitosan-hydroxybenzyl triazole complex enables us to carry out the conjugation of mPEG and trifluoromethylated oxanorbornadiene (OND) in water. CS-mPEG-OND further allows metal-free click to hybridize chitosan (CS) with azido-modified gold nanoparticles (azido-AuNPs) in aqueous solution at room temperature.

Chitosan-Oxanorbornadiene: A Convenient Chitosan Derivative for Click Chemistry without Metal Catalyst Problem.

Click chemistry is considered to be a good pathway to conjugate chitosan with functional molecules due to the ease of the reaction at room temperature. However, as chitosan forms a complex with metal ions, there is a problem with the existence of metal ions in the derivative. The present work demonstrates that chitosan-oxanorbornadiene can provide metal-free Click by showing the optimal condition to introduce oxanorbornadiene, with 80% substitution, and clarifies model reactions of chitosan with azido-modified substrates for the ligation of bioactive molecules.

Encapsulation of ascorbyl palmitate in chitosan nanoparticles by oil-in-water emulsion and ionic gelation processes.

The encapsulation of ascorbyl palmitate (AP) in chitosan particles was carried out by droplet formation via an oil-in-water emulsion, followed by droplet solidification via ionic gelation using sodium triphosphate pentabasic (TPP) as a cross-linking agent. The success of AP encapsulation was confirmed by FT-IR, UV-vis spectrophotometry, TGA, and XRD techniques. The obtained AP-loaded chitosan particles were spherical in shape with an average diameter of 30-100nm as observed by SEM and TEM.