Water-Soluble Chitosan-Quantum Dot Hybrid Nanospheres toward Bioimaging and Biolabeling

Abstract

A facile approach to prepare CdSe/ZnS quantum dot-encapsulated chitosan hybrid nanospheres (CS-QD) is developed by utilizing ethanol-aided counterion complexation in aqueous solution. The obtained CS-QD hybrid nanospheres have not only the loading space provided by the chitosan spherical matrix for loading multiply QDs but also unique fluorescent properties provided by the encapsulated QDs. Moreover, these hybrid nanospheres possess good biocompatibility and optical stability in physiological environment. It is demonstrated that CS-QD hybrid nanospheres can be internalized by tumor cells and hence act as labeling agent in cell imaging by optical microscopy. In addition, CS-QD hybrid nanospheres can be used for imaging of tumor in tumor-bearing mice via intratumoral administration and can accumulate at tumor site via the blood circulation based on intravenous injection. Thus, on the one hand, chitosan nanospheres provide the protection in both colloidal and optical stability arising from QDs and offer biocompatibility. On the other hand, the encapsulated QDs light up polymer nanospheres and display the fate of polymer nanospheres in cells and bodies.

Novel quantum dots–carboxymethyl chitosan nanocomposite nitric oxide donors capable of detecting release of nitric oxide in situ

“…4)-2-amido-2-deoxy-D-glucan (glucosamine) and b-(1 ? 4)-2-acetamido-2-deoxy-D-glucan (acetyl glucosamine) units, produced by deacetylation of chitin extracted from the exoskeleton of crustaceans [5]. Chitosan and its derivatives are biodegradable and biocompatible cationic polymers, which have been widely used in biomedical areas [6].…”

Theranostics: A Way of Modern Medical Diagnostics and the Role of Chitosan

“…Ma et al [28] fabricated carboxymethyl chitosan-CdTe quantum dots. carboxymethyl chitosan on the surface of CdTe QDs had strong binding ability with Zn 2+ results in the advancement of the fluorescence of CdTe QDs.…”

Microfluidic production of single micrometer-sized hydrogel beads utilizing droplet dissolution in a polar solvent

“…51 Spray drier or vibration nozzle techniques have been reported for the production of chitosan hydrogel beads with sizes ranging from several micrometers to several millimeters. [52][53][54] Microfluidic devices have also been used to produce chitosan microbeads; 55,56 however, there are not so many reports on the production of chitosan beads with single micrometer diameters. 57 In this study, methyl acetate, a precursor solution (0.025% or 0.05% chitosan in 0.1M acetic acid aq.…”