Cell labeling efficiency of layer-by-layer self-assembly modified silica nanoparticles
- PDF / 999,597 Bytes
- 5 Pages / 584.957 x 782.986 pts Page_size
- 85 Downloads / 179 Views
Jilong Gou and Xianming Mo Laboratory of Stem Cell Biology, West China Medical School, Sichuan University, Chengdu 610041, People’s Republic of China (Received 30 August 2008; accepted 8 January 2009)
In the present study, we compared cytotoxicity and cell uptake of silica nanoparticles with four different surface coatings generated through layer-by-layer self-assembly. Rabbit mesenchymal stem cells (rMSCs) were labeled with silica nanoparticles of different coatings including poly(ethyleneimine) (PEI), poly(allylamine hydrochloride) (PAH), poly(anetholesulfonic acid, sodium salt) (PAS), and dextran sulfate. The MTT [3-(4, 5-dimethylthiazol-2)-2, 5-diphenyl-2H-tetrazolium bromide] test was performed to quantify the cell biocompatibility. The cellular uptake of those silica nanoparticles was determined by flow cytometry and confocal laser scanning microscopy. The results showed that all examined silica nanoparticles were stable in aqueous phase with high monodispersity. Labeled rMSCs are unaffected in their viability, apoptosis, and differentiation capacities. The silica nanoparticle-coated synthetic polycations such as PEI or PAH have higher cell internalization than negatively charged polyelectrolytes. The ability to control cell uptake of different particles may have applications in cell labeling, cell separation, and other biomedical applications. I. INTRODUCTION
Mesenchymal stem cells (MSCs) are multipotent cells with therapeutic effects in a variety of diseases. Using cell labeling techniques to monitor cell temporal and spatial migration in vivo could be useful in clinical applications.1,2 To date, cellular labeling with fluorescent nanoparticles is considered to be one of the most promising methods, and silica nanoparticles are widely used for cell labeling in biomedical research because silica is quite biocompatible and dye molecules can be easily incorporated into a silica shell. Previous studies have demonstrated that the surface characteristics of nanoparticles are important for particle-cell interactions.2–11 For example, surface functionalization with a positively charged group could enhance the uptake of particles into MSCs.5,6 Moreover, surface modifications of particles through linking to peptide or monoclonal antibodies have been developed for efficient intracellular labeling. However, such modifications have some
a)
Address all correspondence to this author. e-mail: [email protected] This paper was selected as an Outstanding Symposium Paper for the 2008 International Materials Research Conference, Symposium I. DOI: 10.1557/JMR.2009.0179 J. Mater. Res., Vol. 24, No. 4, Apr 2009
potential disadvantages in terms of technical complexity and poor availability in the applications.8–11 Electrostatic layer-by-layer (LbL) self-assembly provides a convenient and versatile method to synthesize nanoparticles with different surface compositions for studying the influence of surface functionalization.3,4,12,13 In the present study, rabbit MSCs (rMSCs) were labeled with silica nanoparticle-coated poly(ethylene
Data Loading...
