Folic acid-targeted magnetic Tb-doped CeF3 fluorescent nanoparticles as bimodal probes for cellular fluorescence and magnetic resonance imaging.

Magnetic fluorescent nanoparticles (NPs) have great potential applications for diagnostics, imaging and therapy. We developed a facile polyol method to synthesize multifunctional Fe3O4@CeF3:Tb@CeF3 NPs with small size (<20 nm), high water solubility and good biocompatibility. The NPs were modified by ligand exchange reactions with citric acid (CA) to obtain carboxyl-functionalized NPs (Fe3O4@CeF3:Tb@CeF3-COOH).

Multifunctional magnetic-hollow gold nanospheres for bimodal cancer cell imaging and photothermal therapy.

Multifunctional nanocomposites combining imaging and therapeutic functions have great potential for cancer diagnosis and therapy. In this work, we developed a novel theranostic agent based on hollow gold nanospheres (HGNs) and superparamagnetic iron oxide nanoparticles (SPIO). Taking advantage of the excellent magnetic properties of SPIO and strong near-infrared (NIR) absorption property of HGNs, such nanocomposites were applied to targeted magnetic resonance imaging (MRI) and photoacoustic imaging (PAI) of cancer cells.

Effective photothermal chemotherapy with docetaxel-loaded gold nanospheres in advanced prostate cancer.

Background: Multifunctional gold nanospheres (MGNs)-loaded with docetaxel (MGN@DTX) were prepared and evaluated for therapeutic efficacy in nude mice bearing human prostate cancer xenografts.

Methods: MGNs were prepared from PEGylated hollow gold nanospheres (HGNs) coated with folic acid and DTPTT chelate. Then, the effect of radiolabelled MGNs ((99m)Tc-MGNs) on PC-3 cell apoptosis was assessed by flow cytometry, while their binding affinity to these cells was evaluated by cell binding assays.

A near-infrared light-controlled system for reversible presentation of bioactive ligands using polypeptide-engineered functionalized gold nanorods.

A near-infrared light-controlled hybrid platform with polypeptide-engineered functionalized gold nanorods has been designed for reversible presentation of the immobilized ligands to cell surface receptors on the engineered materials.

In vitro and in vivo CT imaging using bismuth sulfide modified with a highly biocompatible Pluronic F127.

Probe bismuth sulfide modified with Pluronic F127 (Bi2S3-PF127), which has high biocompatibility and dispersibility, is synthesized using triblock copolymer Pluronic F127 to modify hydrophobic Bi2S3 nanoparticles that are prepared by a hot injection method. TEM results show that most of the probe has a length of about 14.85 ± 1.

Folic acid-conjugated silica-coated gold nanorods and quantum dots for dual-modality CT and fluorescence imaging and photothermal therapy.

Multifunctional nanoparticles (NPs) have great potential for multimodal cancer imaging and effective therapy. We have developed multifunctional NPs (GNR@SiO@QDs) by incorporating gold nanorods (GNRs) and CdSe/ZnS quantum dots (QDs) into silica. Folic acid (FA) as a targeting ligand was covalently conjugated on the surfaces of GNR@SiO@QDs with a silane coupling agent.

Reverse microemulsion-mediated synthesis of Bi2S3-QD@SiO2-PEG for dual modal CT-fluorescence imaging in vitro and in vivo.

Monodispersed Bi2S3-QD@SiO2-PEG nanoparticles are prepared by a one-pot method in a reverse microemulsion system, which exhibited remarkable performances in CT and fluorescence imaging in vitro and in vivo.

Targeted quantum dots fluorescence probes functionalized with aptamer and peptide for transferrin receptor on tumor cells.

Quantum dots (QDs) fluorescent probes based on oligonucleotide aptamers and peptides with specific molecular recognition have attracted much attention. In this paper, CdSe/ZnS QDs probes for targeted delivery to mouse and human cells using aptamer GS24 and peptide T7 specific to mouse/human transferrin receptors were developed. Capillary electrophoresis analyses indicated that the optimal molar ratios of QDs to aptamer or peptide were 1:5.

Distance-dependent metal-enhanced quantum dots fluorescence analysis in solution by capillary electrophoresis and its application to DNA detection.

Here the distance dependence of metal-enhanced quantum dots (QDs) fluorescence in solution is studied systematically by capillary electrophoresis (CE). Complementary DNA oligonucleotides-modified CdSe/ZnS QDs and gold nanoparticles (Au NPs) were connected together in solution by the hybridization of complementary oligonucleotides, and a model system (QD-Au) for the study of metal-enhanced QDs fluorescence was constructed, in which the distance between the QDs and Au NPs was controlled by adjusting the base number of the oligonucleotide. In our CE experiments, the metal-enhanced fluorescence of the QDs solution was only observed when the distance between the QDs and Au NPs ranged from 6.

Synthesis and characterization of multifunctional silica core-shell nanocomposites with magnetic and fluorescent functionalities.

Multifunctional core-shell nanocomposites with a magnetic core and a silica shell doped with lanthanide chelate have been prepared by a simple method. First, citric acid-modified magnetite nanoparticles were synthesized by a chemical coprecipitation method. Then the magnetite nanoparticles were coated with silica shells doped with terbium (Tb(3+)) complex by a modified Stöber method based on hydrolyzing and condensation of tetraethyl orthosilicate (TEOS) and a silane precursor.

NanoART synthesis, characterization, uptake, release and toxicology for human monocyte-macrophage drug delivery.

Background: Factors limiting the efficacy of conventional antiretroviral therapy for HIV-1 infection include treatment adherence, pharmacokinetics and penetration into viral sanctuaries. These affect the rate of viral mutation and drug resistance. In attempts to bypass such limitations, nanoparticles containing ritonavir, indinavir and efavirenz (described as nanoART) were manufactured to assess macrophage-based drug delivery.

Facilitated monocyte-macrophage uptake and tissue distribution of superparmagnetic iron-oxide nanoparticles.

Background: We posit that the same mononuclear phagocytes (MP) that serve as target cells and vehicles for a host of microbial infections can be used to improve diagnostics and drug delivery. We also theorize that physical and biological processes such as particle shape, size, coating and opsonization that affect MP clearance of debris and microbes can be harnessed to facilitate uptake of nanoparticles (NP) and tissue delivery.

Methods: Monocytes and monocyte-derived macrophages (MDM) were used as vehicles of superparamagnetic iron oxide (SPIO) NP and immunoglobulin (IgG) or albumin coated SPIO for studies of uptake and distribution.

Frequency-domain birefringence measurement of biological binding to magnetic nanoparticles.

Optical detection of the frequency-dependent magnetic relaxation signal is used to monitor the binding of biological molecules to magnetic nanoparticles in a ferrofluid. Biological binding reactions cause changes in the magnetic relaxation signal due to an increase in the average hydrodynamic diameter of the nanoparticles. To allow the relaxation signal to be detected in dilute ferrofluids, measurements are made using a balanced photodetector, resulting in a 25 μV/√Hz noise floor, within 50% of the theoretical limit imposed by photon shot noise.

Quantitative DNA hybridization in solution using magnetic/luminescent core-shell nanoparticles.

Nanoscale magnetic/luminescent core-shell particles were used for DNA quantification in a hybridization-in-solution approach. We demonstrated a rapid, simple, and non-polymerase chain reaction-based DNA hybridization-in-solution assay for quantifying bacteria capable of biodegrading methyl tertiary-butyl ether. Fe3O4/Eu:Gd2O3 core-shell nanoparticles synthesized by spray pyrolysis were biofunctionalized with NeutrAvidin.

Surface modification and characterization of magnetic polymer nanospheres prepared by miniemulsion polymerization.

A novel and effective protocol for the surface modification and quantitative characterization of magnetic polymeric nanospheres prepared by miniemulsion polymerization is reported. Composite nanospheres consisting of polymer-coated iron oxide nanoparticles were prepared by the miniemulsion polymerization of methyl methacrylate and divinylbenzene in the presence of magnetic fluid. Surface modification reaction of the magnetic polymer with poly(ethylene glycol) (PEG) was employed to obtain a hydrophilic hydroxyl-group-functionalized magnetic nanospheres.