What is the difference between top down and bottom up methods for ..

56. Jarett BR, Gustafsson B, Kukis DL, Louie AY. Synthesis of 64Cu-labeled magnetic nanoparticles for multimodal imaging. 2008;19:1496-1504

Complex-Shaped Metal Nanoparticles: Bottom-Up ..

Methods using supercritical fluids are also powerful for the synthesis of nanoparticles.

Nanoparticle Synthesis: Top-Down via: Bottom-Up via: ..

67. Sonvico F, Mornet S, Vasseur S, Dubernet C, Jaillard D, Degrouard J, Hoebeke J, Duguet E, Colombo P, Couvreur P. Folate-conjugated iron oxide nanoparticles for solid tumor targeting as potential specific magnetic hyperthermia mediators: Synthesis, physicochemical characterization, and experiments. 2005;16:1181-8

Bottom-up synthesis of Zn1.7GeN1.8O nanoparticles …

65. Zhang G, Liao Y, Baker I. Surface engineering of core/shell iron/iron oxide nanoparticles from microemulsions for hyperthermia. 2010;30:92


Nanowire Synthesis: From Top-Down to Bottom ..

36. Yigit MV, Mazumdar D, Lu Y. MRI detection of thrombin with aptamer functionalized superparamagnetic iron oxide nanoparticles. 2008;19:412-7

Drawing upon the solution-phase synthesis of nanoparticles, ..

35. Yigit MV, Mazumdar D, Kim HK, Lee JH, Odintsov B, Lu Y. Smart “turn-on” magnetic resonance contrast agents based on aptamer-functionalized superparamagnetic iron oxide nanoparticles. 2007;8:1675-1678

Copper Nanoparticles: Synthetic Strategies, Properties …

34. Wang AZ, Bagalkot V, Gu F, Alexis F, Vasilliou C, Cima M, Jon S, Farokhzad O. Novel targeted aptamer-superparamagnetic iron oxide nanoparticle bioconjugates for combined prostate cancer imaging and therapy. 2007;69:S110-1

Copper nanoparticles; synthesis; top-down; bottom-up…

Richards-Kortum reported a novel approach to conjugating nanoparticles and aptamers []. The aptamer was extended to provide a hybridization site for complementary ONT-coated nanoparticles. GNPs (20 nm) were coated with thiol-modified capture ONTs containing a hexa(ethylene glycol) spacer and a complementary sequence for the aptamer extension, and the extended anti-PSMA aptamer was hybridized to capture ONT-coated GNPs by heating the solution at 70°C for 5 min, followed by incubation at room temperature for 30 min. The resulting aptamer-GNPs showed targeted detection of LNCaP (PSMA+) cells via reflectance imaging. This conjugation strategy has several advantages. First, the negatively charged phosphate groups of the ONTs prevented aggregation of the nanoparticles through electrostatic repulsion, leading to nanoparticle stability, even in high-salt environments. Second, aptamers were easily conjugated to the surfaces of nanoparticles via complementary sequence hybridization with the capture ONTs, which preserved the aptamer integrity and stability during bioconjugation. A PEG spacer between the thiol group and the complementary capture sequence of capture ONT improved the hybridization efficiency by minimizing steric hindrance between the gold surface and the hybridization site. Third, a small number of aptamers was needed for binding to the nanoparticles through the short cheap capture ONTs, unlike thiolated aptamers, in which significant concentrations of aptamers are necessary to coat and stabilize the nanoparticles. Finally, multiplexing capabilities can be obtained by incorporating other types of molecules (targeting, delivery, imaging, or therapeutic agents) into the nanoparticles.

for synthesis of copper nanoparticles through the bottom-up or ..

Perez . utilized the click reaction to conjugate folate onto multifunctional iron oxide nanoparticles []. They synthesized poly(acrylic acid) (PAA)-coated iron oxide nanoparticles and encapsulated lipophilic fluorescence dyes (dialkylcarbocyanine fluorophores) within the hydrophobic coating layers on the nanoparticles to provide dual imaging capabilities. The nanoparticles were functionalized with alkyne groups via a reaction with propargyl amine and EDC/NHS, followed by further reaction with azide-containing folate via the click chemistry. A hydrophobic anticancer drug, Taxol, was then encapsulated to yield multifunctional theranostic nanoparticles. A thick polymeric coating layer, 40 nm thick according to DLS measurements, played a key role in incorporating hydrophobic guest molecules. The MTT and cellular uptake assessments indicated the folate-decorated nanoparticles' specificity toward target tumor cells (A549). MRI studies demonstrated the ability of those theranostic agents to behave as sensitive MRI contrast agents.

A variety of “bottom-up” synthesis ..

50. Sun C, Kim D, Fang C, Bhattarai N, Veiseh O, Kievit F, Stephen Z, Lee D, Ellenbogen RG, Ratner B, Zhang M. PEG-mediated synthesis of highly dispersive multifunctional superparamagnetic nanoparticles: their physicochemical properties and function . 2010;4:2402-10

TOP DOWN AND BOTTOM UP APPROACH |authorSTREAM

(A) Semipermeabilization of intact cells allows for nanoparticle targeting to a variety of intracellular biomarkers. Indicators of cell growth, activation, and survival. (B) Profiling scant tumor cell populations for key biomarkers of cancer using DMR. Detection of eight biomarkers in eight different cell lines using MFNPs based on NMR signal (top). Magnetic measurements showed an excellent correlation with the marker expression levels determined independently using antibody staining (bottom). Reproduced with permission from ref. [].