A viability study of 3D tumor spheroids after their mass-density characterization via an innovative flow-based biophysical method

The simple measurement of mass density, size and weight of sphere-like 3D cell models has been recently enabled by a specifically conceived flow-based method. Here we demonstrate that such technique also allows the post-analysis collection of live 3D tumor spheroids, without compromising their viability.

Design Of A Rapid And Reversible Fluorescence Assay To Detect Covid-19 And Other Pathogens

We describe a rapid and reusable biophysical method to assay COVID-19 and other pathogens. The method uses fluorescent sensors (i.e. molecular beacons) designed to detect COVID-19 RNA or any RNA of interest, concurrent with an internal control without the need for amplification. The molecular beacons are stem-loop structures in which a ∼10 nucleotide loop region has the complementary sequence of a region of the target RNA, and a fluorophore and quencher are placed on the 5’ and 3’ ends of the stem. The energy of hybridization of the loop with its target is designed to be greater than the hybridization energy of the energy of the stem so that when the beacon encounters its target RNA, the structure opens resulting in dequenching of the fluorophore. Here, we designed a COVID-19 beacon that is completely quenched in its native form and undergoes a 50-fold increase in fluorescence when exposed to nanomolar amounts of synthetic viral oligonucleotide. No changes in intensity are seen when control RNA is added. A control beacon to a human GAPDH RNA, chosen for its high levels in saliva, behaved similar to the COVID-19 beacon. This increase in fluorescence with beacon opening can be completely reversed upon addition of single stranded DNA complementary to COVID-19 beacon loop region. Beacons can be attached to an insert matrix allowing their use in concentrated form and can be made from morphilino oligonucleotides that are resistant to RNases. We present an analysis of the parameters that will allow the development of test strips to detect virus in aerosol, body fluids and community waste.Statement of significanceA platform for reusable and rapid detection of COVID-19 RNA and other pathogenic RNAs without the need for amplification or sophisticated instrumentation in a complex environment is described.

Analysis of proportion of nucleic acids and proteins in glandular stomach wall in chickens during experimental escherichiosis

A method for spectral analysis of the ratios of organic substances in a cell using the "Stains all" metachromatic luminescent dye (in its own modification) has been developed. This method is used to establish the ratio of nucleic acids and proteins in the integumentary epithelium of the mucous membrane and in the interlobular connective tissue of the submucosa tissue of the glandular stomach of chickens. Using the developed biophysical method, we studied the ratios of these organic substances in the glandular stomach of healthy and infected with E. coli chickens. The dynamics of the ratios of nucleic acids and proteins detected in the wall of the glandular stomach of the control group chicks fits into the picture of a moderate and uniform increase in the values of these indicators, corresponding to an age increase of the chickens. In chickens affected by Escherichiosis, a curve that reflects the dynamics of the ratios includes a three-fold increase in their values. The results obtained using the developed method indicate the possibility of using it to detect early metabolic changes in the glandular stomach of chickens before the appearance of a characteristic pathomorphological and clinical picture. Thus, this method can provide invaluable assistance in developing a fundamentally new approach in creation of modern technologies for the diagnosis, prevention and treatment of widespread disease Escherichiosis.

Sub-3 Å resolution structure of apoferritin using a multi-purpose TEM with a side-entry cryo-holder

SummaryThe structural analysis of protein complexes by cryo-electron microscopy (cryo-EM) single particle analysis (SPA) has had great impact as a biophysical method in recent years. Many results of cryo-EM SPA are based on state-of-the-art cryo-electron microscopes customized for SPA. These are currently only available in limited locations around the world, where securing machine time is highly competitive. One potential solution for this time-competitive situation is to reuse existing multi-purpose equipment. Here, we used a multi-purpose TEM with a side entry cryo-holder at our facility to evaluate the potential of high-resolution SPA. We report a 3 Å resolution map of apoferritin with local resolution extending to 2.6 Å. The map clearly showed two positions of an aromatic side chain. We also verified the optimal imaging conditions depending on different electron microscope and camera combinations. This study demonstrates the possibilities of more widely available and established electron microscopes, and their applications for cryo-EM SPA.

Polymorphism of human telomeric quadruplexes with drugs: a multi-technique biophysical study

A multi-technique biophysical method is used to study the ligand binding to G-quadruplex DNA.

ИЗУЧЕНИЕ МЕХАНИЗМОВ РАСШИРЕНИЯ СПЕКТРА ЦИТОТОКСИЧНОСТИ ПЕГИЛИРОВАННЫХ ЛИПОСОМАЛЬНЫХ СИСТЕМ ДОСТАВКИ ПРОТИВООПУХОЛЕВЫХ ПРЕПАРАТОВ МЕТОДОМ СПИНОВЫХ ЗОНДОВ

Pegylated liposomal anticancer drugs, in particular, doxorubicin have an expansion of the spectrum of toxicity. To study the mechanisms of influence of polyethylene glycol (PEG) on the structure of cell membranes, the sensitive biophysical method of spin probes was used. Using the spin probe method, it has been shown that in the presence of an increased prothrombin blood index, increased blood viscosity and a high density of red blood cells and other blood components, large and long fragments of PEG molecules located on the surface of pegylated liposomal delivery systems can effectively interact with the membranes of neighboring cells. The list of even these possible effects, which were determined and described by us in experiments for bovine serum albumin, liposomes, erythrocytes and skin tissue, suggests that the expansion of the spectrum of the specific toxicity of pegylated liposomes may be directly or indirectly associated with the mechanisms of action of PEG on proteins and cell membranes.

The Effectiveness of Bioresonance Method on Human Health

Introduction: Bioresonance is a holistic physical method that can be used diagnostically and therapeutically to treat various diseases. Bioresonance uses the electromagnetic waves it receives from the patient. This biophysical method of treatment alters the energy field of the affected organism, increasing the effectiveness of the autoimmune system, thus improving the patient’s overall health. Methods: A quasi-experimental design was used to examine whether bioresonance had an effect on the symptoms of the patients. Statistical data processing involves a study of various parameters such as age, gender, studies, occupation, intolerance or illness as well as the existence and balancing of allergic charges. The study included 311 patients from doctors and bio-coordinating laboratories in Athens, Thessaloniki, Volos and Xanthi. The sample of the study included both men (120 subjects - 38.58%) and women (191 subjects – 61.42%), aged from 2 to 76 years old. The age group with the largest number of patients included those aged from 31 to 45. Results: The patients under treatment came forward with symptoms mostly nasal (61.09%), followed by eye, respiratory, cutaneous, and gastrointestinal symptoms. Most of the patients (90%) observe no symptoms at all or show significant improvement of their symptoms after a period of 12 months of bioresonance treatment. These results show that bioresonance intervention had a significant effect on the improvement of symptoms and this improvement is even obvious 12 months after the intervention; p<.01. Conclusion: We believe that the forthcoming results contribute to a better understanding of the effect of bioresonance on the human body and its affect in preventing and restoring health issues.