Preparation and Characterization of Biocompatible Quaternized Chitosan Nanoparticles Encapsulating CdS Quantum DotsYan Li1,2, Min Hu2, Baiwen Qi3, Xiaoying Wang1,4 and Yumin Du1*
- Corresponding Author:
- Yumin Du
Wuhan University, China
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Received date: May 14, 2011; Accepted date: July 16, 2011; Published date: July 18, 2011
Citation: Li Y, Hu M, Qi B, Wang X, Du Y (2011) Preparation and Characterization of Biocompatible Quaternized Chitosan Nanoparticles Encapsulating CdS Quantum Dots. J Biotechnol Biomaterial 1:108. doi:10.4172/2155-952X.1000108
Copyright: © 2011 Li Y, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Nanoparticles were produced by encapsulating CdS quantum dots (QDs) with quaternized chitosan (N-(2- hydroxyl) propyl-3-trimethyl ammonium chitosan chloride, HTCC), in order to improve general biocompatibility and stability of pure QDs. The properties of CdS QDs encapsulated HTCC nanoparticles (HTCC/CdS QDs) can be controlled by changing the mass ratios of QD to HTCC (16:1, 8:1, 4:1, 2:1, 1:1, 1:2, 1:4, 1:8). Characterizations of HTCC/CdS QDs nanoparticles were performed using ultraviolet-visible, fluorescence spectrometry, and sizezeta analysis. As compared with nonencapsulated QDs, these HTCC/CdS QDs nanoparticles would keep their original optical properties, and greatly improve the quantum yield and stability in room temperature. The quantum yield can be improved from 9% to 23%. When the mass ratio of QD and HTCC was 1.0, the nanoparticles had the highest quantum yield (23%). After being stored for a week, the nanoparticles could still keep stable and high fluorescence intensity, while that of non-encapsulated QDs almost disappeared. In vitro 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) cytotoxicity tests on primary myoblast cells suggested that the cytotoxicity of the QDs was greatly reduced after HTCC encapsulation. Therefore, due to the increase of biocompability, HTCC/ CdS QDs nanoparticles can be potentially used in biological applications and labeling of biomolecules.