25 research outputs found
Polymersomes, smaller than you think: ferrocene as a TEM probe to determine core structure
No full textBy incorporating ferrocene into the hydrophobic membrane of PEG-b-PCL polymersome nanoparticles it is possible to selectively visualize their core using Transmission Electron Microscopy (TEM). Two different sizes of ferrocene-loaded polymersomes with mean hydrodynamic diameters of approximately 40 and 90 nm were prepared. Image analysis of TEM pictures of these polymersomes found that the mean diameter of the core was 4-5 times smaller than the mean hydrodynamic diameter. The values obtained also allow the surface diameter and internal volume of the core to be calculated
Nuclear Targeting Dynamics of Gold Nanoclusters for Enhanced Therapy of HER2(+) Breast Cancer
No full textRecent advances in fluorescent metal nanoclusters have spurred tremendous interest In nanomedicine due to the ease of fabrication, excellent biocompatibility, and, more Importantly, excellent wavelength-dependent tunability. Herein, we report our findings on fluorescent BSA-protected gold nanoclusters (AuNCs), similar to 2 nm in size conjugated with Herceptin (AuNCs-Her), for specific targeting and nuclear localization in ErbB2 over-expressing breast cancer cells and tumor tissue as a novel fluorescent agent for simultaneous imaging and cancer therapy. More interestingly, we found that AuNCs-Her could escape the endolysosomal pathway and enter the nucleus of cancer cells to enhance the therapeutic efficacy of Herceptin. We elucidate the diffusion characteristics (diffusion time and number of diffusers) and concentration of the fluorescing dusters in the nucleus of live cells. Our findings also suggest that the nuclear localization effect of AuNCs-Her enhances the anticancer therapeutic efficacy of Herceptin as evidenced by the induction of DNA damage. This study not only discusses a new nanomaterial platform for nuclear delivery of drugs but also provides important insights on nuclear targeting for enhanced therapy
Tunable emission from InAs quantum dots on InP nanotemplates
No full textSelective area chemical beam epitaxy is used to fabricate submicron [100]-oriented InP ridges with well-defined, defect-free (011) sidefacets and (001) tops. Following the deposition of two monolayers of InAs on such nanotemplates and subsequent capping with InP, photoluminescence spectra show for wider ridges strong emission from a thin InAs quantum well and, as the ridge width is reduced, a gradual appearance of a quantum dot emission at lower energy. The method allows continuous tuning on a given sample in a single growth run of both the quantum dot density and the emission wavelength. The result is a consequence of adatom diffusion from the ridge sidefacets onto the top (001) facet, which increases the amount of InAs beyond the critical thickness for three-dimensional nucleation to occur. Compared with growth on planar InP(001) substrates, InAs self-assembled quantum dots grown on these nanotemplates are more uniform as revealed by a twofold reduction in emission linewidth at 4 K.NRC publication: Ye
Gold nanoparticles explore cells: cellular uptake and their use as intracellular probes
No full textUnderstanding uptake of nanomaterials by cells and their use for intracellular sensing is important for studying their interaction and toxicology as well as for obtaining new biological insight. Here, we investigate cellular uptake and intracellular dynamics of gold nanoparticles and demonstrate their use in reporting chemical information from the endocytotic pathway and cytoplasm. The intracellular gold nanoparticles serve as probes for surface-enhanced Raman spectroscopy (SERS) allowing for biochemical characterisation of their local environment. In particular, in this work we compare intracellular SERS using non-functionalised and functionalised nanoparticles in their ability to segregate different but closely related cell phenotypes. The results indicate that functionalised gold nanoparticles are more efficient in distinguishing between different types of cells. Our studies pave the way for understanding the uptake of gold nanoparticles and their utilisation for SERS to give rise to a greater biochemical understanding in cell-based therapies
Development of new fluorescent silica and multifunctional nanoparticles for bio-imaging and diagnostics
No full textSilica nanoparticles are effective fluorophore carriers with high potential in
imaging, diagnostics, and therapy. The particles are resistant to drastic change
of environmental conditions (pH, temperature etc. and insulate the dyes so as to
protect them from photobleaching. Silica chemistry is also versatile and affords
an easy modification of the particle composition and surface to integrate
targeting ligands or to integrate other nanoparticles. Regardless of their
advantages, there exists a lack of dye diversity in the literature that is connected
to a low affinity for
potential tools for biology and medicineThis thesis describes the development
of an alternative method for the synthesis of fluorescent silica nanoparticles and
their modification to incorporate iron oxide and gold. cont/d
SU‐FF‐J‐152: Dosimetry On Gold Nanoparticle: A Microscopic and Macroscopic Study Using Monte Carlo Simulations
No full textObservation Of Resonance Modes In Inas/ingaasp/inp Quantum Dot Microdisk Resonators
No full textWe present the development of quantum dot microdisk resonators grown by Chemical Beam Epitaxy (CBE). Two stacked layers of InAs Quantum Dots (QDs) embedded in a lattice-matched InGaAsP (λ g=1.4 μm) are grown on (100) InP substrate. Evidence of the presence of resonant modes are observed both by eletroluminescense and absorption spectra at room temperature. © The Electrochemical Society.141505509McCall, S.L., Levi, A.F.J., Slusher, R.E., Pearton, S.J., Logan, R.A., (1992) Appl. Phys. Lett, 60, p. 289Nishi, K., Saito, H., Sugou, S., Lee, J., (1999) Appl. Phys. Lett, 74, p. 1111Kiravittaya, S., Rastelli, A., Schmidt, O.G., (2005) Appl. Phys. Lett, 87Ustinov, V.M., Meleev, N.A., Zhukov, A.E., Kovsh, A.R., Egorov, A.Y., Lunev, A.V., Volovik, B.V., Bimberg, D., (1999) Appl. Phys. Lett, 74, p. 2815Barik, S., Tan, H.H., Jagadish, C., (2006) Nanotechnology, 17, p. 1867Saito, H., Nishi, K., Sugou, S., (2001) Appl. Phys. Lett, 78, p. 267Jeong, W.G., Dapkus, P.D., Lee, U.H., Lim, J.S., Lee, D., Lee, B.T., (2001) Appl. Phys. Lett, 78, p. 1171Wang, R.H., Stintz, A., Varangis, P.M., Newell, T.C., Li, H., Malloy, K.J., Lester, L.F., (2001) IEEE Photonics Technol. Lett, 13, p. 767Schwertberger, R., Gold, D., Reithmaier, J.P., Forchel, A., (2002) IEEE Photonics Technol. Lett, 14, p. 735Ni, C., Allen, Poole, P.J., Marshall, P., Fraser, J., Raymond, S., Fafard, S., (2002) Appl. Phys. Lett, 80, p. 3629Fafard, S., Wasilewski, Z., McCaffrey, J., Raymond, S., Charbonneau, S., (1996) Appl. Phys. Lett, 68, p. 991Li, H., Daniels-Race, T., Wang, Z., (1999) J. Cryst. Growth, 200, p. 321Poole, P.J., McCaffrey, J., Williams, R.L., Lefebvre, J., Chithrani, D., (2001) J. Vac. Sci. Technol. B, 19, p. 1467Xua, B., Wang, Z.G., Chen, Y.H., Jin, P., Ye, X.L., Liu, H.Y., Zhang, Z.Y., Liu, F.Q., (2004) IEEE 13th International Conference on Semiconducting and Insulating Materials, 113Nieto, L., Bortoleto, J.R.R., Cotta, M.A., Magalhães-Paniago, R., Gutiérrez, H.R., (2007) Appl. Phys. Lett, 91, p. 063122Allen, C.N., Finnie, P., Raymond, S., Wasilewski, Z.R., Fafard, S., (2001) Appl. Phys. Lett, 79, p. 2701Sztucki, M., Schülli, T.U., Metzger, T.H., Beham, E., Schuh, D., Chamard, V., (2004) Superlattices Microstruct, 36, p. 1
