Formulation, characterization, and in vitro evaluation of quantum dots loaded in poly(lactide)-vitamin E TPGS nanoparticles for cellular and molecular imaging

✍ Scribed by Jie Pan; Yan Wang; Si-Shen Feng

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 574 KB
• Volume: 101
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.21924

✦ Synopsis

Abstract

We developed a novel system of poly(lactide acid)‐d‐α‐tocopheryl polyethylene glycol 1000 succinate (PLA‐TPGS) nanoparticles (NPs) for quantum dots (QDs) formulation to improve imaging effects and reduce side effects as well as to promote a sustainable imaging. The QDs‐loaded PLA‐TPGS NPs were prepared by a modified solvent extraction/evaporation method, which were then characterized by laser light scattering (LLS) for size and size distribution; field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and transmission electron microscope (TEM) for surface morphology. Surface chemistry of the QDs‐loaded PLA‐TPGS NPs was analyzed by X‐ray photoelectron microscopy (XPS) and Fourier transform infra‐red spectroscopy (FTIR). Encapsulation efficiency of the QDs in the polymeric nanoparticles was measured by inductively coupled plasma optical emission spectrometry (ICP‐OES). The photostability of the QDs formulated in the PLA‐TPGS nanoparticles was investigated as changes in the florescence intensity versus the irradiation time. Confocal laser scanning microscopy (CLSM) was used to image the cellular uptake of the QDs‐loaded NPs by MCF‐7 cells. Methylthiazolyldiphenyl‐tetrazolium (MTT) assay was employed to assess the viability of MCF‐7 cells incubated with the QDs formulated by the PLA‐TPGS NPs versus the mercaptoacetic acid (MAA)‐coated QDs. It was found that the QDs formulated in the PLA‐TPGS NPs can result in higher fluorescence intensity and higher photostability than the bare QDs as well as lower cytotoxicity than the MAA‐coated QDs. Biotechnol. Bioeng. 2008;101: 622–633. © 2008 Wiley Periodicals, Inc.