Diamond-like carbon (DLC) surface treatment decreases biofilm burden by S. aureus on titanium alloy in vitro- a pilot study.

Purpose: Periprosthetic joint infection is a complication of total joint arthroplasty with treatment costs over $1.6 billion dollars per year in the US with high failure rates. Therefore, generation of coatings that can prevent infection is paramount.

Unusual Hydration Properties of Choline Fluoride-Based Deep Eutectic Solvents.

The hydration properties of the fluoride-based deep eutectic solvent ethalineF [a solution of choline fluoride in ethylene glycol (EG) at a 1:2 molar ratio] are studied and compared to the most common deep eutectic solvent ethaline (the solution of choline chloride in EG at 1:2 molar ratio). The densities of the deep eutectic solvent (DES) based on choline fluoride in EG (ethalineF) and its mixtures with water as cosolvent are measured over the temperature range of 298-323 K. The excess properties, including excess molar volumes, excess partial molar volumes, and viscosity deviations from ideal behavior, are calculated for ethalineF/water and ethaline/water mixtures and compared.

Effect of chloride substitution on interfacial charge transfer processes in MAPbI perovskite thin film solar cells: planar mesoporous.

For photovoltaic devices based on hybrid organic-inorganic perovskite thin films, the cell architecture is a vital parameter in defining the macroscopic performance. However, the understanding of the correlation between architecture and carrier dynamics in perovskite thin films has remained elusive. In this work, we utilize concerted materials characterization and optical measurements to investigate the role of chloride addition in PSC devices with two different architectures.

High-performance iron oxide nanoparticles for magnetic particle imaging - guided hyperthermia (hMPI).

Magnetic particle imaging (MPI) is an emerging imaging modality that allows the direct and quantitative mapping of iron oxide nanoparticles. In MPI, the development of tailored iron oxide nanoparticle tracers is paramount to achieving high sensitivity and good spatial resolution. To date, most MPI tracers being developed for potential clinical applications are based on spherical undoped magnetite nanoparticles.

Magnetic Nanoparticles: Material Engineering and Emerging Applications in Lithography and Biomedicine.

We present an interdisciplinary overview of material engineering and emerging applications of iron oxide nanoparticles. We discuss material engineering of nanoparticles in the broadest sense, emphasizing size and shape control, large-area self-assembly, composite/hybrid structures, and surface engineering. This is followed by a discussion of several non-traditional, emerging applications of iron oxide nanoparticles, including nanoparticle lithography, magnetic particle imaging, magnetic guided drug delivery, and positive contrast agents for magnetic resonance imaging.

Iron Oxide and Titanium Dioxide Nanoparticle Effects on Plant Performance and Root Associated Microbes.

In this study, we investigated the effect of positively and negatively charged Fe₃O₄ and TiO₂ nanoparticles (NPs) on the growth of soybean plants (Glycine max.) and their root associated soil microbes. Soybean plants were grown in a greenhouse for six weeks after application of different amounts of NPs, and plant growth and nutrient content were examined.

Magnetic Particle Imaging Tracers: State-of-the-Art and Future Directions.

Magnetic particle imaging (MPI) is an emerging imaging modality with promising applications in diagnostic imaging and guided therapy. The image quality in MPI is strongly dependent on the nature of its iron oxide nanoparticle-based tracers. The selection of potential MPI tracers is currently limited, and the underlying physics of tracer response is not yet fully understood.

Detection of Lysyl Oxidase-Like 2 (LOXL2), a Biomarker of Metastasis from Breast Cancers Using Human Blood Samples.

Metastasis accounts for 90% of the mortality associated with breast cancer. Upregulated expression of members of the lysyl oxidase (LOX) family of secreted copper amine oxidases catalyzes the crosslinking of collagens and elastin in the extracellular matrix. LOXs are linked to the development and metastatic progression of breast cancers.

Highly efficient antibacterial iron oxide@carbon nanochains from wüstite precursor nanoparticles.

A new hydrothermal synthesis approach involving the carbonization of glucose in the presence of wüstite (FeO) nanoparticles is presented, which leads to the fabrication of rapidly acting and potent antibacterial agents based on iron oxide@carbon (IO@C) nanochains. By using nonmagnetic FeO precursor nanoparticles that slowly oxidize into the magnetic Fe3O4 crystal structure under hydrothermal conditions, we were able to prepare well-defined and short-length IO@C nanochains that are highly dispersed in aqueous media and readily interact with bacterial cells, leading to a complete loss in bacterial cell viability within short incubation times at minimal dosage. The smaller IO@C nanochains synthesized using the FeO precursor nanoparticles can reach above 2-fold enhancement in microbe-killing activity when compared to the larger nanochains fabricated directly from Fe3O4 nanoparticles.

Effect of metal precursor on the growth and electrochemical sensing properties of Pt-Ag nanoboxes.

Pt-Ag nanoboxes prepared using a Pt(4+) versus Pt(2+) precursor show not only stoichiometric, but also catalytic effects on the nanobox growth, resulting in metal content and surface morphology differences. Electrochemical studies on these nanoboxes reveal the combined importance of composition and hollow, rough-walled nanostructure for improved detection of electroactive molecules.

Iron oxide-loaded hollow mesoporous silica nanocapsules for controlled drug release and hyperthermia.

Magnetic field-responsive iron oxide-loaded hollow mesoporous silica nanocapsules that exhibit high drug loading capacity were synthesized using polymer nanospheres as sacrificial templates. Due to their magnetic field induced heating and remotely triggered drug release capabilities, these hybrid nanomaterials provide an excellent platform for the combination of hyperthermia and chemotherapy.

Magnetic particle imaging: advancements and perspectives for real-time in vivo monitoring and image-guided therapy.

Magnetic particle imaging (MPI) is an emerging biomedical imaging technology that allows the direct quantitative mapping of the spatial distribution of superparamagnetic iron oxide nanoparticles. MPI's increased sensitivity and short image acquisition times foster the creation of tomographic images with high temporal and spatial resolution. The contrast and sensitivity of MPI is envisioned to transcend those of other medical imaging modalities presently used, such as magnetic resonance imaging (MRI), X-ray scans, ultrasound, computed tomography (CT), positron emission tomography (PET) and single photon emission computed tomography (SPECT).

Adsorption of Cd2+ on carboxyl-terminated superparamagnetic iron oxide nanoparticles.

The affinity of Cd(2+) toward carboxyl-terminated species covalently bound to monodisperse superparamagnetic iron oxide nanoparticles, Fe(3)O(4)(np)-COOH, was investigated in situ in aqueous electrolytes using rotating disk electrode techniques. Strong evidence that the presence of dispersed Fe(3)O(4)(np)-COOH does not affect the diffusion limiting currents was obtained using negatively and positively charged redox active species in buffered aqueous media (pH = 7) devoid of Cd(2+). This finding made it possible to determine the concentration of unbound Cd(2+) in solutions containing dispersed Fe(3)O(4)(np)-COOH, 8 and 17 nm in diameter, directly from the Levich equation.

Detection of Alpha-Methylacyl-CoA Racemase (AMACR), a Biomarker of Prostate Cancer, in Patient Blood Samples Using a Nanoparticle Electrochemical Biosensor.

Although still commonly used in clinical practice to screen and diagnose prostate cancer, there are numerous weaknesses of prostate-specific antigen (PSA) testing, including lack of specificity and the inability to distinguish between aggressive and indolent cancers. A promising prostate cancer biomarker, alpha-methylacyl-CoA racemase (AMACR), has been previously demonstrated to distinguish cancer from healthy and benign prostate cells with high sensitivity and specificity. However, no accurate clinically useful assay has been developed.

Delivery and efficacy of a cancer drug as a function of the bond to the gold nanoparticle surface.

In this feature article, gold nanoparticle conjugates loaded with phthalocyanine-based PDT drugs are prepared and tested for delivery efficiency and PDT efficacy on HeLa cancer cells. It could be shown that the delivery and PDT outcome are strongly affected by the bond that links the drug load to the nanoparticle surface. Whereas labile amino adsorption to the Au nanoparticle surface allows for efficient drug release into the cancer cells and for efficient PDT, a covalent thiol bond to the Au nanoparticle leads to the delivery of the drug into cell vesicles, and no PDT effect is observed.

Highly efficient drug delivery with gold nanoparticle vectors for in vivo photodynamic therapy of cancer.

A highly efficient drug vector for photodynamic therapy (PDT) drug delivery was developed by synthesizing PEGylated gold nanoparticle conjugates, which act as a water-soluble and biocompatible "cage" that allows delivery of a hydrophobic drug to its site of PDT action. The dynamics of drug release in vitro in a two-phase solution system and in vivo in cancer-bearing mice indicates that the process of drug delivery is highly efficient, and passive targeting prefers the tumor site. With the Au NP-Pc 4 conjugates, the drug delivery time required for PDT has been greatly reduced to less than 2 h, compared to 2 days for the free drug.

Effect of the functionalization of the axial phthalocyanine ligands on the energy transfer in QD-based donor-acceptor pairs.

This study examines the electronic coupling between quantum dots (QDs) and molecules on their surfaces as a function of the modality of their interaction. As a probe, the energy transfer (ET) between CdSe QDs and phthalocyanines (Pcs) was monitored and evaluated with regard to the functionalization of the axial phthalocyanine ligand, bulkiness of the functional group bridging the QD donor and Pc acceptor, and the number of the functionalized axial ligands. New silicon PCs and their conjugates with CdSe QDs were synthesized.

Observation of non-Förster-type energy-transfer behavior in quantum dot-phthalocyanine conjugates.

The effect of linker chain length on the energy transfer from CdSe quantum dots (QDs) to silicon phthalocyanine (Pc) photodynamic therapy agents was investigated by steady-state and femtosecond time-resolved spectroscopy with 500 nm light for the specific excitation of the QD energy donor. The conjugation between the QD and the Pc was achieved with linker chains varying from 4 to 9 bond lengths by incorporating 1-6 methylene groups into the axial ligand of the Pc. With increasing chain length, the energy-transfer efficiency increased, which appears to be opposed to a purely Förster-type resonance energy-transfer behavior that is commonly discussed for the energy transfer in QD conjugates.

Quantum dot-based energy transfer: perspectives and potential for applications in photodynamic therapy.

Quantum dots have emerged as an important class of material that offers great promise to a diverse range of applications ranging from energy conversion to biomedicine. Here, we review the potential of using quantum dots and quantum dot conjugates as sensitizers for photodynamic therapy (PDT). The photophysics of singlet oxygen generation in relation to quantum dot-based energy transfer is discussed and the possibility of using quantum dots as photosensitizer in PDT is assessed, including their current limitations to applications in biological systems.

Investigation of the crystallization process in 2 nm CdSe quantum dots.

Investigation of the growth of CdSe nanocrystals ( approximately 160 atoms) to the uniquely stable size of 2 nm allows the monitoring of the crystallization process in semiconductor quantum dots. By using a combination of optical techniques, high-resolution transmission electron microscopy (HRTEM), and powder X-ray diffractometry (XRD), new phenomena were explored during the CdSe nanocrystal growth process, which involved significant morphological reconstruction and crystallization of the initially formed amorphous nanoparticles. During the crystallization, the absorption onset of the CdSe quantum dots blue shifted toward higher energies at 3 eV (414 nm), while the photoluminescence red shifted to lower energies.

Ligand effect on the growth and the digestion of Co nanocrystals.

The reaction product of cobalt carbonyl decomposition depends on the concentration of the oleic acid ligand. With a low concentration of ligand, nanocrystals nucleate and grow to large ferromagnetic particles through the process of Ostwald ripening and coalescence coarsening. With a high concentration of ligand, stable cluster complexes are formed.

Semiconductor quantum dots for photodynamic therapy.

The applicability of semiconductor QDs in photodynamic therapy (PDT) was evaluated by studying the interaction between CdSe QDs with a known silicon phthalocyanine PDT photosensitizer, Pc4. The study revealed that the QDs could be used to sensitize the PDT agent through a fluorescence resonance energy transfer (FRET) mechanism, or interact directly with molecular oxygen via a triplet energy-transfer process (TET). Both mechanisms result in the generation of reactive singlet oxygen species that can be used for PDT cancer therapy.