Design of solid powder particles for a needle-free injection

Background: In 2020, the COVID19 pandemic has shown the medical need for vaccinations. The conventional method of vaccine application is intravascular injection of a liquid solution. However, this method is associated with some disadvantages, such as a high risk of infection. Purpose(s): The approach of a needle-free ballistic administration accelerates solid powder particles to a sufficient speed so that they are able to penetrate into the skin and address target Langerhans cells. For this purpose, the particles require certain characteristics (Weissmueller et al., 2017). The main criteria for a successful application is the particle size as well as the density (Maa et al., 2004). Method(s): One potential production process is freeze-drying out of a solution with a subsequent milling step (abbreviated to FD). Another modified approach is spray-freeze drying (abbreviated to SFD). Dried powders are treated afterwards by ultrasonic microsieving (6000 vibrations per seconds for ten minutes) in order to segregate a useable fraction (38 mum to 75 mum). Tap density was determined according to the protocol by Ph.eur. guidelines. Helium pycnometry determines the true density. The magnitude of density is described by the quotient of tap density rho tap and pycometric density rho He-pycnometer. Result(s): Estimated density of examined samples containing trehalose and mannitol could not exceed 50%. Conclusion(s): The described techniques reveal a quite porous structure of the product. This structure might not be sufficient for particles to successfully penetrate into the skin. These powder particles might burst upon the surface. However the dimension of the speed has to be considered as well as it plays a crucial role as well.

Radiation source with enhanced virucide effectiveness based on a mixture of helium and iodine vapor

Subject of study. A source of spontaneous emission (a lamp) in the ultraviolet spectral range excited by a capacitive discharge was investigated. Iodine vapor and mixtures of iodine vapor with inert gases were used as the operating gas medium of the lamp. Conditions for enhancements in specific output parameters of the lamp emission were investigated. Excitation conditions under which the lamp emits predominantly at the iodine atomic line with a wavelength of 206.16 nm were determined. Aim of study. The primary aim of the study was to investigate the spectral and energy characteristics of the lamp based on the iodine vapor, which is promising for the development of a radiation source with enhanced virucidal effectiveness for ultraviolet disinfection of a human environment contaminated with pathogenic microorganisms including severe acute respiratory syndrome coronavirus 2 (SARSCoV-2). Method. In this study, the composition and pressure of the operating medium were optimized. In addition, the excitation mode of the lamp emission was optimized by changing the repetition rate of voltage pulses. Main results. At a specific excitation power of approximately 1.3 mW/cm3 and partial pressures of iodine vapor and helium of approximately 2.5 and 7 Torr, respectively, the line of an iodine atom with a wavelength of 206.16 nm dominates in the output lamp spectrum, and the specific emission power at the outer surface of the lamp tube is approximately 3 mW/cm2. Practical significance. The emission of the investigated lamp is in the spectral range of 200–225 nm, which is promising in terms of developing technology for safe ultraviolet inactivation of pathogenic microorganisms including SARS-CoV-2. © 2022 Optica Publishing Group.

Emergence of Silicon Photonics in the Field of Biomedical Sensing Applications: A Review

In the last few decades, the human body is prone to many different types of infectious diseases. This involves making use of technologies for detecting and monitoring the factors responsible for these diseases, and the devices should be free from any kind of harmful radiations. Photonics is considered to be one of the new advancements in the field of technology which can fulfill the need or requirement of biomedical sensing applications. The scope of this review paper summarizes the concept of designing methods and material structures for biomedical applications. These designing methods include plane wave expansion, surface plasmon resonance (SPR), Helium ion lithography, band-gap variations, and refractive index variation of the material. The losses that are incurred or induced during the wave propagation includes adsorption, attenuation, reflection, and diffraction. There are several physical structures of the materials mainly 1D, 2D, 3D, three-layer silicon, five-layer, seven-layer, etc. The above mentioned material structures are used to detect cancer cell, DNA and protein concentration, identifying different mutation of SARS virus which includes COVID-19, as well as in the field of bio-sensing, bio-screening, and drug delivery system. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Pathomorphological changes due to helium inhalation: an expert case report

BACKGROUND: Helium, being an inert substance, does not have a significant effect on the human body, but sometimes at very high concentrations in the air, it can cause suffocation and a state of oxygen deficiency. Oxygen-helium therapy has proven to be the most effective recovery, rehabilitation, and treatment for all types of lung damage and reduced saturation. It is even included in the recommendations for preventing, diagnosing, and treating COVID-19. Deaths due to inhalation of inert gases, especially helium, are sporadic in forensic practice. As a rule, the probability of death in such cases is most often associated with man-made accidents or violations of safety regulations when performing technological processes and operations related to the use of gas. Safety instructions for handling helium warn of possible damage to the mucous membrane of the eyes and frostbite of the skin, as well as mechanical injury when a heavy gas cylinder falls. CASE PRESENTATION: Inert gases do not interact with other chemicals. However, we encountered a suicide case where an inert gas was chosen as a means. Inhalation of helium caused macro- and micromorphological changes in the human body, which led to a fatal outcome. The case is illustrated by photographs of microscopic preparations, which demonstrate the absence of specific signs of toxic effects on the organs and tissues of the deceased. CONCLUSION: Despite the substance's extreme volatility, the compressed gas's pressure and low temperature can cause various injuries and even death. The study of general pathomorphology can be helpful in the conduct of a forensic medical examination. © Authors, 2021

Untersuchung des reaktiven Intermediats der RNA Autohydrolyse mittels kryogener Infrarotspektroskopie in der Gasphase

Im Laufe der COVID‐19 Pandemie haben mRNA‐basierte Impfstoffe an immenser Bedeutung gewonnen. Massenspektrometrie ist für die Entwicklung und Analyse von modifizierten RNA Molekülen unerlässlich, setzt jedoch ein grundlegendes Verständnis über Fragmentierungsprozesse voraus. Analog zu der Zersetzung von RNA in Lösung durch Autohydrolyse, kann die Spaltung des RNA Rückgrats ebenso in der Gasphase stattfinden. Bislang sind die Fragmentierungsmechanismen jedoch unzureichend untersucht. In dieser Arbeit wurden Intermediate aus isolierten RNA Dinukleotiden in der Gasphase generiert und mittels kryogener Infrarotspektroskopie in Helium‐Nanotröpfchen untersucht. Die experimentellen Daten, unterstützt durch Dichtefunktionaltheorie, liefern Hinweise dafür, dass die Bildung eines fünfgliedrigen zyklischen Phosphat‐Intermediats begünstigt ist, während lineare oder sechsgliedrige Strukturen ausgeschlossen werden können. Weiterhin zeigen die Experimente, dass eine zusätzliche, bekannte Reaktion von RNA Nukleotiden in Lösung auch in der Gasphase induziert werden kann: die Tautomerisierung von Cytosin. Die beiden beobachteten Reaktionen spiegeln daher universelle und intrinsische Eigenschaften der untersuchten Moleküle wider.

Oxygen-helium gas mixture «Heliox» for the treatment of respiratory failure in patients with new coronavirus infection Covid-19 (randomized single-center controlled trial)

IntRoDuCtIon Treatment of respiratory failure in pneumonia caused by coronavirus infection (COVID-19) is still an unsolved problem that requires a comprehensive approach and the development of new methods that expand the range of possibilities of modern therapy. There is evidence that the heated oxygen-helium mixture has a positive effect on gas exchange in the infiltration zone by improving both ventilation and diffusion. AIM oF StuDY To evaluate the effectiveness of the inclusion of a heated oxygen-helium mixture HELIOX (70% Helium/ 30% Oxygen) in the complex intensive care of respiratory failure of pneumonia caused by SARS-CoV-2 infection. MAteRIAL AnD MethoDS The study included 60 patients with confirmed viral pneumonia caused by COVID-19. The patients were randomized into two groups: group 1 (n=30) — patients who were treated with the standard COVID-19 treatment protocol with the heated oxygen-helium mixture HELIOX, and group 2 (control) (n=30) — patients who received standard therapy. Lethality was studied for 28 days, the time in days until a steady increase in SpO2>96% was achieved when breathing atmospheric air;the time until the patient is transferred from the intensive care unit (ICU) to the general department. ReSuLtS Inhalation of the HELIOX mixture (70% Helium / 30% Oxygen) resulted in a faster recovery of the hemoglobin oxygen saturation index (SpO2). Starting from day 3, these differences became statistically significant. The time in days from inclusion in the study to a persistent increase in the degree of oxygen saturation of hemoglobin (SpO2>96%) when breathing atmospheric air in the group with inhalation of the HELIOX mixture was less — 8 (7;10), compared to 10 (8;13) in the control group (p=0.006). In the group with inhaled HELIOX mixture, the median treatment time in the ICU was 8 (7;9.5) days vs 13 (8;17) days (p<0.001) in the comparison group. ConCLuSIonS Inhalation of the HELIOX mixture (70% Helium / 30% Oxygen) led to a faster recovery of the hemoglobin oxygen saturation index SpO2, which contributed to reduction in the duration of oxygen therapy and a decrease in mortality. © 2021 Sklifosovsky Research Institute for Emergency Medicine. All rights reserved.

Imaging of SARS-CoV-2 infected Vero E6 cells by helium ion microscopy.

Helium ion microscopy (HIM) offers the opportunity to obtain direct views of biological samples such as cellular structures, virus particles, and microbial interactions. Imaging with the HIM combines sub-nanometer resolution, large depth of field, and high surface sensitivity. Due to its charge compensation capability, the HIM can image insulating biological samples without additional conductive coatings. Here, we present an exploratory HIM study of SARS-CoV-2 infected Vero E6 cells, in which several areas of interaction between cells and virus particles, as well as among virus particles, were imaged. The HIM pictures show the three-dimensional appearance of SARS-CoV-2 and the surface of Vero E6 cells at a multiplicity of infection of approximately 1 with great morphological detail. The absence of a conductive coating allows for a distinction between virus particles bound to the cell membrane and virus particles lying on top of the membrane. After prolonged imaging, it was found that ion-induced deposition of hydrocarbons from the vacuum renders the sample sufficiently conductive to allow for imaging even without charge compensation. The presented images demonstrate the potential of the HIM in bioimaging, especially for the imaging of interactions between viruses and their host organisms.