Spectral study of fluorone dyes adsorption on chitosan-based polyelectrolyte complexes

Physico-chemical characterization and cytotoxicity evaluation of curcumin loaded in chitosan/chondroitin sulfate nanoparticles

“…It can be inferred that the positivity of the nanoparticles is related to the characteristics of the cationic chitosan molecule, while negativity relates to the deprotonation of the amino groups in more basic medium. Slyusareva et al [30] studied the polyelectrolytic complex formed from chitosan and chondroitin sulfate and also verified that the pH of the chitosan influences the characteristics of the resulting complexes. The pH values under study were 3.8, 4.6 and 5.6 and the results showed the formation of particles with similar polymodal distributions at all pH values and positive zeta potentials, due to the protonation of the free amine groups of chitosan at acid pH.…”

“…The pH increase makes the density of these positive charges and the repulsive force among the free \ \NH 2 groups decrease, favoring the formation of smaller nanoparticles. It causes reduction in the zeta potential, since, at pH values close to the pKa of chitosan (6.3 and 7.2), there is a lower amount of protonated amine groups (\ \NH 3 + ) available for interaction [18,30,31]. Thus, at pH 6.0, the values of the hydrodynamic diameter, PDI and zeta potential of the nanoparticles were significantly lower by comparison with their values at pH 3.5.…”

Synthesis and characterization of chitosan-based polyelectrolyte complexes, doped by quantum dots

“…The method used for the synthesis of QD-free PECs from chitosan and chondroitin sulfate was similar to the described previously [8]. Chitosan solution of 0.1% w/v concentration was pre-cleaned from insoluble impurities by filtration through a paper filter.…”

“…Finally, the obtained PEC solution was filtered through a PVDF membrane (Roth, Germany) with 0.45 µm pore size. The PEC concentration in the filtrate was estimated taking into consideration the results of a similar synthesis [8] by the value of ~5×10…”

“…An electrostatic interaction between polycationic chitosan molecules and anionic species is widely used to produce cross-linked chitosan micro-and nanoparticles [3][4][5]. The application of anionic biopolymers as counter-ions allows combining biodegradability and biocompatibility of the polyelectrolyte complexes with their highly efficient absorbance of the charged species [6][7][8].…”