Determining the size and shape dependence of gold nanoparticle uptake into mammalian cells

Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada.
Nano Letters (Impact Factor: 12.94). 05/2006; 6(4):662-8. DOI: 10.1021/nl052396o
Source: PubMed

ABSTRACT We investigated the intracellular uptake of different sized and shaped colloidal gold nanoparticles. We showed that kinetics and saturation concentrations are highly dependent upon the physical dimensions of the nanoparticles (e.g., uptake half-life of 14, 50, and 74 nm nanoparticles is 2.10, 1.90, and 2.24 h, respectively). The findings from this study will have implications in the chemical design of nanostructures for biomedical applications (e.g., tuning intracellular delivery rates and amounts by nanoscale dimensions and engineering complex, multifunctional nanostructures for imaging and therapeutics).

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    ABSTRACT: Nonlinear photothermal microscopy is applied in the imaging of biological tissues stained with chlorophyll and hematoxylin. Experimental results show that this type of organic molecules, which absorb light but transform dominant part of the absorbed energy into heat, may be ideal probes for photothermal imaging without photochemical toxicity. Picosecond pump and probe pulses, with central wavelengths of 488 and 632 nm, respectively, are spectrally filtered from a compact supercontinuum fiber laser source. Based on the light source, a compact and sensitive super-resolution imaging system is constructed. Further more, the imaging system is much less affected by thermal blurring than photothermal microscopes with continuous-wave light sources. The spatial resolution of nonlinear photothermal microscopy is ~ 188 nm. It is ~ 23% higher than commonly utilized linear photothermal microscopy experimentally and ~43% than conventional optical microscopy theoretically. The nonlinear photothermal imaging technology can be used in the evaluation of biological tissues with high-resolution and contrast.
    Optics Express 04/2015; 23(8). DOI:10.1364/OE.23.009762 · 3.53 Impact Factor
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    ABSTRACT: Objective. To kill urothelial cancer cells while preserving healthy cells, this study used photothermal therapy (PTT). PTT techniques target urothelial cancer cells using gold nanoparticles (GNPs) and a green light laser. Materials and Methods. The GNPs were conjugated with anti-Mucin 7 antibodies, which acted as a probe for targeting tumor cells. Conjugated GNPs were exposed to a green light laser (532 nm) with sufficient thermal energy to kill the transitional cell carcinomas (TCCs). Results. According to our results, nanoparticles conjugated with Mucin 7 antibodies damaged all types of cancer cells (MBT2, T24, 9202, and 8301) at relatively low energy levels (i.e., 500 laser shots at 10 W/cm(2) in power, 1.6 Hz in frequency, and 300 ms in duration). Nonconjugated nanoparticles required 30 W/cm(2) or more to achieve the same effect. Cell damage was directly related to irradiation time and applied laser energy. Conclusions. The minimally invasive PTT procedure combined with Mucin 7 targeted GNPs is able to kill cancer cells and preserve healthy cells. The success of this treatment technique can likely be attributed to the lower amount of energy required to kill targeted cancer cells compared with that required to kill nontargeted cancer cells. Our in vitro pilot study yielded promising results; however, additional animal studies are required to confirm these findings.
    01/2015; 2015:813632. DOI:10.1155/2015/813632
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    ABSTRACT: Background During the last decade nanoparticles have gained attention as promising drug delivery agents that can transport through the blood brain barrier. Recently, several studies have demonstrated that specifically targeted nanoparticles which carry a large payload of therapeutic agents can effectively enhance therapeutic agent delivery to the brain. However, it is difficult to draw definite design principles across these studies, owing to the differences in material, size, shape and targeting agents of the nanoparticles. Therefore, the main objective of this study is to develop general design principles that link the size of the nanoparticle with the probability to cross the blood brain barrier. Specifically, we investigate the effect of the nanoparticle size on the probability of barbiturate coated GNPs to cross the blood brain barrier by using bEnd.3 brain endothelial cells as an in vitro blood brain barrier model. Results The results show that GNPs of size 70 nm are optimal for the maximum amount of gold within the brain cells, and that 20 nm GNPs are the optimal size for maximum free surface area. Conclusions These findings can help understand the effect of particle size on the ability to cross the blood brain barrier through the endothelial cell model, and design nanoparticles for brain imaging/therapy contrast agents.
    Journal of Nanobiotechnology 03/2015; 13(1). DOI:10.1186/s12951-015-0075-7 · 4.08 Impact Factor


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