Background: Cancer remains a formidable global health challenge, currently affecting nearly 20 million individuals worldwide. Due to the absence of universally effective treatments, ongoing research explores diverse strategies to combat this disease. Recent efforts have concentrated on developing combined drug regimens and targeted therapeutic approaches.
View Article and Find Full Text PDFMutations in connexin 26 (Cx26) cause hearing disorders of a varying degree. Herein, to identify compounds capable of restoring the function of mutated Cx26, a novel miniaturized microarray-based screening system was developed to perform an optical assay of Cx26 functionality. These molecules were identified through a viability assay using HeLa cells expressing wild-type (WT) Cx26, which exhibited sensitivity toward the HSP90 inhibitor radicicol in the submicromolar concentration range.
View Article and Find Full Text PDFThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has created a public crisis. Many medical and public institutions and businesses went into isolation in response to the pandemic. Because SARS-CoV-2 can spread irrespective of a patient's course of disease, these institutions' continued operation or reopening based on the assessment and control of virus spread can be supported by targeted population screening.
View Article and Find Full Text PDFBackground: Since social distancing during the COVID-19-pandemic had a profound impact on professional life, this study investigated the effect of PCR testing on on-site work.
Methods: PCR screening, antibody testing, and questionnaires offered to 4,890 working adults in Lower Saxony were accompanied by data collection on demographics, family status, comorbidities, social situation, health-related behavior, and the number of work-related contacts. Relative risks (RR) with 95 % confidence intervals were estimated for the associations between regular PCR testing and other work and health-related variables, respectively, and working on-site.
Protein microarray screenings identified fungal natural products from the azaphilone family as potent inhibitors of SARS-CoV-2 spike protein binding to host ACE2 receptors. Cohaerin F, as the most potent substance from the cohaerin group, led to more than 50% less binding of ACE2 and SARS-CoV-2 spike protein. A survey for structurally related azaphilones yielded the structure elucidation of six new multiformins E-J (-) and the revision of the stereochemistry of the multiformins.
View Article and Find Full Text PDFBackground: Detection of seroconversion after SARS-CoV-2-infection or vaccination is relevant to discover subclinical cases and recognize patients with a possible immunity.
Objectives: Test performance, effects of age, time-point of seroconversion and immune status regarding neutralizing antibodies (NAbs) and T-cell-reactivity were investigated.
Study Design: Two antibody assays (Viramed-Test for S/N-specific IgG, Roche-Test for N-specific IgA, -M, -G) were evaluated with classified samples.
While many proteins are known clients of heat shock protein 90 (Hsp90), it is unclear whether the transcription factor, thyroid hormone receptor beta (TRb), interacts with Hsp90 to control hormonal perception and signaling. Higher Hsp90 expression in mouse fibroblasts was elicited by the addition of triiodothyronine (T3). T3 bound to Hsp90 and enhanced adenosine triphosphate (ATP) binding of Hsp90 due to a specific binding site for T3, as identified by molecular docking experiments.
View Article and Find Full Text PDFPurpose: The COVID-19 pandemic affects students in a myriad of different ways. Our prospective, longitudinal study in a cohort of students in Hannover, Germany explores behavioral patterns during escalating COVID-19 restrictions.
Methods: In total, 777 students between the age of 9 and 20 were assessed for their activity engagement, travel patterns, and self-assessed compliance with protective recommendations at six time points between June 2020 and June 2021 (3,564 observations) and were monitored for severe acute respiratory syndrome coronavirus 2 infection by nasal swab polymerase chain reaction and serum antibody titers.
The development of multifunctional nanoscale systems that can mediate efficient tumor targeting, together with high cellular internalization, is crucial for the diagnosis of glioma. The combination of imaging agents into one platform provides dual imaging and allows further surface modification with targeting ligands for specific glioma detection. Herein, transferrin (Tf)-decorated niosomes with integrated magnetic iron oxide nanoparticles (MIONs) and quantum dots (QDs) were formulated (PEGNIO/QDs/MIONs/Tf) for efficient imaging of glioma, supported by magnetic and active targeting.
View Article and Find Full Text PDFAging and overweight increase the risk of developing type 2 diabetes mellitus. In this cross-sectional study, we aimed to investigate the potential mediating role of T-EMRA cells and inflammatory markers in the development of a decreased insulin sensitivity. A total of 134 healthy older volunteers were recruited (age 59.
View Article and Find Full Text PDFEven though the administration of chemotherapeutic agents such as erlotinib is clinically established for the treatment of breast cancer, its efficiency and the therapy outcome can be greatly improved using RNA interference (RNAi) mechanisms for a combinational therapy. However, the cellular uptake of bare small interfering RNA (siRNA) is insufficient and its fast degradation in the bloodstream leads to a lacking delivery and no suitable accumulation of siRNA inside the target tissues. To address these problems, non-ionic surfactant vesicles (niosomes) were used as a nanocarrier platform to encapsulate Lifeguard (LFG)-specific siRNA inside the hydrophilic core.
View Article and Find Full Text PDFLung surfactants are used for reducing alveolar surface tension in preterm infants to ease breathing. Phospholipid films with surfactant proteins regulate the activity of alveolar macrophages and reduce inflammation. Aberrant skin wound healing is characterized by persistent inflammation.
View Article and Find Full Text PDFNiosomes are non-ionic surfactant-based vesicles with high promise for drug delivery applications. They can be rapidly prepared via microfluidics, allowing their reproducible production without the need of a subsequent size reduction step, by controlled mixing of two miscible phases of an organic (lipids dissolved in alcohol) and an aqueous solution in a microchannel. The control of niosome properties and the implementation of more complex functions, however, thus far are largely unknown for this method.
View Article and Find Full Text PDFHere, we show that human Connexin 26 (hCx26 or Cx26WT) hemichannel opening rapidly enables the transport of small molecules when triggered by temperature and by compensation of the Ca blockade with EDTA. Point mutations within Cx26 were analysed by a novel optical microarray-based Lucifer Yellow uptake assay or by two electrode voltage clamp (TEVC) on frog oocytes to monitor simultaneous activities of channel proteins. Point mutations L90P, F161S, R184P or K188N influenced the temperature-dependent activity drastically.
View Article and Find Full Text PDFHuman mesenchymal stem cells derived from adipose tissue (AD-hMSCs) represent a promising source for tissue engineering and are already widely used in cell therapeutic clinical trials. Until today, an efficient and sustainable cell labeling system for cell tracking does not exist. We evaluated transient transfection through electroporation for cell labeling and compared it with lentiviral transduction for AD-hMSCs.
View Article and Find Full Text PDFAdv Biochem Eng Biotechnol
October 2019
Aptazymes are synthetic molecules composed of an aptamer domain and a catalytic active nucleic acid unit, which may be a ribozyme or a DNAzyme. In these constructs the aptamer domain serves as a molecular switch that can regulate the catalytic activity of the ribozyme or DNAzyme subunit. This regulation is triggered by binding of the aptamers target molecule, which causes significant structural changes in the aptamer and thus in the entire aptazyme.
View Article and Find Full Text PDFThe heat shock protein 90 (Hsp90) family plays a critical role in maintaining the homeostasis of the intracellular environment for human and prokaryotic cells. Hsp90 orthologues were identified as important target proteins for cancer and plant disease therapies. It was shown that gambogic acid (GBA) has the potential to inhibit human Hsp90.
View Article and Find Full Text PDFMethods Mol Biol
February 2019
The deposition of living cells on microarray surfaces can be used to create physiologically relevant architecture in vitro. Such living cell microarrays enable the reconstruction of biological processes outside the body in a miniaturized format and have many advantages over traditional cell culture. The present protocol offers an option for the preparation and analysis of living primary and stem cell-based microarrays utilizing the standard microarray equipment (contact-free piezoelectric nanoprinter, microarray scanner), as well as microscopy.
View Article and Find Full Text PDFThirteen new reblastatin derivatives, with alkynyl, amino and fluoro substituents on the aromatic ring, were prepared by a chemo-biosynthetic approach using an AHBA(-) mutant strain of Streptomyces hygroscopicus, the geldanamycin producer. The inhibitory potencies of these mutaproducts and of an extended library of natural products and derivatives were probed with purified heat shock proteins (Hsps), obtained from Leishmania braziliensis (LbHsp90) as well as from human sources (HsHsp90). We determined the activities of potential inhibitors by means of a displacement assay in which fluorescence-labelled ATP competes for the ATP binding sites of Hsps in the presence of the inhibitor in question.
View Article and Find Full Text PDFA facile method for testing ATP binding in a highly miniaturized microarray environment using human HSP70 and DnaK from Mycobacterium tuberculosis as biological targets is reported. Supported by molecular modelling studies we demonstrate that the position of the fluorescence label on ATP has a strong influence on the binding to human HSP70. Importantly, the label has to be positioned on the adenine ring and not to the terminal phosphate group.
View Article and Find Full Text PDFThe selection of aptamers represents a promising route in the development of high affinity ligands. In these processes the formation of by-products is a common problem during the PCR-based amplification of complex oligonucleotide libraries. One approach to overcome this drawback is to separate each template oligonucleotide into an individual reaction compartment provided by a droplet.
View Article and Find Full Text PDFAdvanced theranostic nanomedicine is a multifunctional approach which combines the diagnosis and effective therapy of diseased tissues. Here, we investigated the preparation, characterization and in vitro evaluation of theranostic liposomes. As is known, liposome-quantum dot (L-QD) hybrid vesicles are promising nanoconstructs for cell imaging and liposomal-topotecan (L-TPT) enhances the efficiency of TPT by providing protection against systemic clearance and allowing extended time for it to accumulate in tumors.
View Article and Find Full Text PDFDesoxyribonucleic acid (DNA) microarray experiments generate big datasets. To successfully harness the potential information within, multiple filtering, normalization, and analysis methods need to be applied. An in-depth knowledge of underlying physical, chemical, and statistical processes is crucial to the success of this analysis.
View Article and Find Full Text PDFThe application of DNA microarrays for high throughput analysis of genetic regulation is often limited by the fluorophores used as markers. The implementation of multi-scan techniques is limited by the fluorophores' susceptibility to photobleaching when exposed to the scanner laser light. This paper presents combined mechanical and chemical strategies which enhance the photostability of cyanine 3 and cyanine 5 as part of solid state DNA microarrays.
View Article and Find Full Text PDFLiving cell microarrays are a highly efficient cellular screening system. Due to the low number of cells required per spot, cell microarrays enable the use of primary and stem cells and provide resolution close to the single-cell level. Apart from a variety of conventional static designs, microfluidic microarray systems have also been established.
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