Detection of Apoptosis in Cancer Cells Using Heat Shock Protein 70 and p53 Antibody Conjugated Quantum Dot Nanoparticles

Clinical experience indicates that enhanced level of heat shock protein 70 (Hsp70) and p53 correlates with poor prognosis due to malignant cell overexpression of these proteins in tumor progression. Cadmium selenide quantum dots (QDs) were synthesized in aqueous solution using mercaptopropionic acid and L-cysteine (L-Cys) as ligands. They were conjugated with a monoclonal antibody (Ab) to p53 and cmHp70.1 to Hsp70 for detection of cancer cell apoptosis that was demonstrated in the experiment by fluorescent confocal microscopy both for breast carcinoma cells and for thyroid tissue. It is shown that in comparison with organic dyes, quantum dots have superior photostability of tracking apoptosis in cancer cells for longer time

Magnetotactic Bacteria and Magnetosomes: Basic Properties and Applications

Magnetotactic bacteria (MTB) belong to several phyla. This class of microorganisms exhibits the ability of magneto-aerotaxis. MTB synthesize biominerals in organelle-like structures called magnetosomes, which contain single-domain crystals of magnetite (Fe3O4) or greigite (Fe3S4) characterized by a high degree of structural and compositional perfection. Magnetosomes from dead MTB could be preserved in sediments (called fossil magnetosomes or magnetofossils). Under certain conditions, magnetofossils are capable of retaining their remanence for millions of years. This accounts for the growing interest in MTB and magnetofossils in paleo- and rock magnetism and in a wider field of biogeoscience. At the same time, high biocompatibility of magnetosomes makes possible their potential use in biomedical applications, including magnetic resonance imaging, hyperthermia, magnetically guided drug delivery, and immunomagnetic analysis. In this review, we attempt to summarize the current state of the art in the field of MTB research and applications

Enhanced Osseointegrative Properties of Ultra-Fine-Grained Titanium Implants Modified by Chemical Etching and Atomic Layer Deposition

An integrated approach combining severe plastic deformation (SPD), chemical etching (CE), and atomic layer deposition (ALD) was used to produce titanium implants with enhanced osseo­integration. The relationship between morphology, topography, surface composition, and bioactivity of ultra-fine-grained (UFG) titanium modified by CE and ALD was studied in detail. The topography and morphology have been studied by means of atomic force microscopy, scanning electron microscopy, and the spectral ellipsometry. The composition and structure have been determined by X-ray fluorescence analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. The wettability of the surfaces was examined by the contact angle measurement. The bioactivity and biocompatibility of the samples were studied <i>in vitro</i> and <i>in vivo</i>. CE of UFG titanium in basic (NH₄OH/H₂O₂) or acidic (H₂SO₄/H₂O₂) piranha solution significantly enhances the surface roughness and leads to microstructures, nanostructures, and hierarchical micro-/nanostructures on the surfaces. <i>In vitro</i> results demonstrate deterioration of adhesion, proliferation, and differentiation of MC3T3-E1 osteoblasts cell for CE samples as compared to the non-treated ones. Atomic layer deposition of crystalline titanium oxide onto the CE samples increased hydrophilicity, changed the surface composition, and enhanced significantly <i>in vitro</i> characteristics. <i>In vivo</i> experiments demonstrated non-toxicity of the implants. Etching in basic piranha solution with subsequent ALD significantly improved implant osseo­integration as compared with the non-modified samples

Gold Nanoparticle Mediated Multi-Modal CT Imaging of Hsp70 Membrane-Positive Tumors

Imaging techniques such as computed tomographies (CT) play a major role in clinical imaging and diagnosis of malignant lesions. In recent years, metal nanoparticle platforms enabled effective payload delivery for several imaging techniques. Due to the possibility of surface modification, metal nanoparticles are predestined to facilitate molecular tumor targeting. In this work, we demonstrate the feasibility of anti-plasma membrane Heat shock protein 70 (Hsp70) antibody functionalized gold nanoparticles (cmHsp70.1-AuNPs) for tumor-specific multimodal imaging. Membrane-associated Hsp70 is exclusively presented on the plasma membrane of malignant cells of multiple tumor entities but not on corresponding normal cells, predestining this target for a tumor-selective in vivo imaging. In vitro microscopic analysis revealed the presence of cmHsp70.1-AuNPs in the cytosol of tumor cell lines after internalization via the endo-lysosomal pathway. In preclinical models, the biodistribution as well as the intratumoral enrichment of AuNPs were examined 24 h after i.v. injection in tumor-bearing mice. In parallel to spectral CT analysis, histological analysis confirmed the presence of AuNPs within tumor cells. In contrast to control AuNPs, a significant enrichment of cmHsp70.1-AuNPs has been detected selectively inside tumor cells in different tumor mouse models. Furthermore, a machine-learning approach was developed to analyze AuNP accumulations in tumor tissues and organs. In summary, utilizing mHsp70 on tumor cells as a target for the guidance of cmHsp70.1-AuNPs facilitates an enrichment and uniform distribution of nanoparticles in mHsp70-expressing tumor cells that enables various microscopic imaging techniques and spectral-CT-based tumor delineation in vivo

Recombinant Interleukin-1 Receptor Antagonist Conjugated to Superparamagnetic Iron Oxide Nanoparticles for Theranostic Targeting of Experimental Glioblastoma

Cerebral edema commonly accompanies brain tumors and contributes to neurologic symptoms. The role of the interleukin-1 receptor antagonist conjugated to superparamagnetic iron oxide nanoparticles (SPION–IL-1Ra) was assessed to analyze its anti-edemal effect and its possible application as a negative contrast enhancing agent for magnetic resonance imaging (MRI). Rats with intracranial C6 glioma were intravenously administered at various concentrations of IL-1Ra or SPION–IL-1Ra. Brain peritumoral edema following treatment with receptor antagonist was assessed with high-field MRI. IL-1Ra administered at later stages of tumor progression significantly reduced peritumoral edema (as measured by MRI) and prolonged two-fold the life span of comorbid animals in a dose-dependent manner in comparison to control and corticosteroid-treated animals (P < .001). Synthesized SPION–IL-1Ra conjugates had the properties of negative contrast agent with high coefficients of relaxation efficiency. In vitro studies of SPION–IL-1Ra nanoparticles demonstrated high intracellular incorporation and absence of toxic influence on C6 cells and lymphocyte viability and proliferation. Retention of the nanoparticles in the tumor resulted in enhanced hypotensive T2-weighted images of glioma, proving the application of the conjugates as negative magnetic resonance contrast agents. Moreover, nanoparticles reduced the peritumoral edema confirming the therapeutic potency of synthesized conjugates. SPION–IL-1Ra nanoparticles have an anti-edemal effect when administered through a clinically relevant route in animals with glioma. The SPION–IL-1Ra could be a candidate for theranostic approach in neuro-oncology both for diagnosis of brain tumors and management of peritumoral edema

Properties of substances inhibiting aggregation of oxidized GAPDH: Data on the interaction with the enzyme and the impact on its intracellular content

This data is related to our paper “Small molecules preventing GAPDH aggregation are therapeutically applicable in cell and rat models of oxidative stress” (Lazarev et al. [1]) where we explore therapeutic properties of small molecules preventing GAPDH aggregation in cell and rat models of oxidative stress. The present article demonstrates a few of additional properties of the chemicals shown to block GAPDH aggregation such as calculated site for targeting the enzyme, effects on GAPDH glycolytic activity, influence on GAPDH intracellular level and anti-aggregate activity of pure polyglutamine exemplifying a denatured protein

Magnetic Properties of Bacterial Magnetosomes Produced by Magnetospirillum caucaseum SO-1

In this study, the magnetic properties of magnetosomes isolated from lyophilized magnetotactic bacteria Magnetospirillum caucaseum SO-1 were assessed for the first time. The shape and size of magnetosomes and cell fragments were studied by electron microscopy and dynamic light scattering techniques. Phase and elemental composition were analyzed by X-ray and electron diffraction and Raman spectroscopy. Magnetic properties were studied using vibrating sample magnetometry and electron paramagnetic resonance spectroscopy. Theoretical analysis of the magnetic properties was carried out using the model of clusters of magnetostatically interacting two-phase particles and a modified method of moments for a system of dipole–dipole-interacting uniaxial particles. Magnetic properties were controlled mostly by random aggregates of magnetosomes, with a minor contribution from preserved magnetosome chains. Results confirmed the high chemical stability and homogeneity of bacterial magnetosomes in comparison to synthetic iron oxide magnetic nanoparticles