Plasma medicine: Opportunities for nanotechnology in a digital age

Nanotechnology-based theranostic and prophylactic approaches against SARS-CoV-2

SARS-CoV-2 (COVID-19) pandemic has been an unpredicted burden on global healthcare system by infecting over 700 million individuals, with approximately 6 million deaths worldwide. COVID-19 significantly impacted all sectors, but it very adversely affected the healthcare system. These effects were much more evident in the resource limited part of the world. Individuals with acute conditions were also severely impacted. Although classical COVID-19 diagnostics such as RT-PCR and rapid antibody testing have played a crucial role in reducing the spread of infection, these diagnostic techniques are associated with certain limitations. For instance, drawback of RT-PCR diagnostics is that due to degradation of viral RNA during shipping, it can give false negative results. Also, rapid antibody testing majorly depends on the phase of infection and cannot be performed on immune compromised individuals. These limitations in current diagnostic tools require the development of nanodiagnostic tools for early detection of COVID-19 infection. Therefore, the SARS-CoV-2 outbreak has necessitated the development of specific, responsive, accurate, rapid, low-cost, and simple-to-use diagnostic tools at point of care. In recent years, early detection has been a challenge for several health diseases that require prompt attention and treatment. Disease identification at an early stage, increased imaging of inner health issues, and ease of diagnostic processes have all been established using a new discipline of laboratory medicine called nanodiagnostics, even before symptoms have appeared. Nanodiagnostics refers to the application of nanoparticles (material with size equal to or less than 100 nm) for medical diagnostic purposes. The special property of nanomaterials compared to their macroscopic counterparts is a lesser signal loss and an enhanced electromagnetic field. Nanosize of the detection material also enhances its sensitivity and increases the signal to noise ratio. Microchips, nanorobots, biosensors, nanoidentification of single-celled structures, and microelectromechanical systems are some of the most modern nanodiagnostics technologies now in development. Here, we have highlighted the important roles of nanotechnology in healthcare sector, with a detailed focus on the management of the COVID-19 pandemic. We outline the different types of nanotechnology-based diagnostic devices for SARS-CoV-2 and the possible applications of nanomaterials in COVID-19 treatment. We also discuss the utility of nanomaterials in formulating preventive strategies against SARS-CoV-2 including their use in manufacture of protective equipment, formulation of vaccines, and strategies for directly hindering viral infection. We further discuss the factors hindering the large-scale accessibility of nanotechnology-based healthcare applications and suggestions for overcoming them.

Opportunities of Electronic and Optical Sensors in Autonomous Medical Plasma Technologies

Low temperature plasma technology is proving to be at the frontier of emerging medical technologies with real potential to overcome escalating healthcare challenges including antimicrobial and anticancer resistance. However, significant improvements in efficacy, safety, and reproducibility of plasma treatments need to be addressed to realize the full clinical potential of the technology. To improve plasma treatments recent research has focused on integrating automated feedback control systems into medical plasma technologies to maintain optimal performance and safety. However, more advanced diagnostic systems are still needed to provide data into feedback control systems with sufficient levels of sensitivity, accuracy, and reproducibility. These diagnostic systems need to be compatible with the biological target and to also not perturb the plasma treatment. This paper reviews the state-of-the-art electronic and optical sensors that might be suitable to address this unmet technological need, and the steps needed to integrate these sensors into autonomous plasma systems. Realizing this technological gap could facilitate the development of next-generation medical plasma technologies with strong potential to yield superior healthcare outcomes.

Plasma Scalpels: Devices, Diagnostics, and Applications

The plasma scalpel is an application of gas discharges in electrosurgery. This paper introduces the device structure and physicochemical parameters of the two types of plasma scalpels, namely, a single-electrode Ar discharge device (argon plasma coagulation) and a two-electrode discharge device in normal saline. The diagnostic methods, including the voltage and current characteristics, optical emission spectroscopy, electron spin resonance, and high-speed imaging, are introduced to determine the critical process parameters, such as the plasma power, the gas temperature, the electron density, and the density of active species, and study the ignition dynamics of the plasma discharges in water. The efficacy of the plasma scalpel is mainly based on the physical effects of the electric current and electric field, in addition to the chemical effects of high-density energetic electrons and reactive species. These two effects can be adjusted separately to increase the treatment efficacy of the plasma scalpel. Specific guidance on further improvements of the plasma scalpel devices is also provided.

Possible Synergies of Nanomaterial-Assisted Tissue Regeneration in Plasma Medicine: Mechanisms and Safety Concerns

Cold atmospheric plasma and nanomedicine originally emerged as individual domains, but are increasingly applied in combination with each other. Most research is performed in the context of cancer treatment, with only little focus yet on the possible synergies. Many questions remain on the potential of this promising hybrid technology, particularly regarding regenerative medicine and tissue engineering. In this perspective article, we therefore start from the fundamental mechanisms in the individual technologies, in order to envision possible synergies for wound healing and tissue recovery, as well as research strategies to discover and optimize them. Among these strategies, we demonstrate how cold plasmas and nanomaterials can enhance each other's strengths and overcome each other's limitations. The parallels with cancer research, biotechnology and plasma surface modification further serve as inspiration for the envisioned synergies in tissue regeneration. The discovery and optimization of synergies may also be realized based on a profound understanding of the underlying redox- and field-related biological processes. Finally, we emphasize the toxicity concerns in plasma and nanomedicine, which may be partly remediated by their combination, but also partly amplified. A widespread use of standardized protocols and materials is therefore strongly recommended, to ensure both a fast and safe clinical implementation.

Application of nanotechnology in the early diagnosis and comprehensive treatment of gastrointestinal cancer

Gastrointestinal cancer (GIC) is a common malignant tumour of the digestive system that seriously threatens human health. Due to the unique organ structure of the gastrointestinal tract, endoscopic and MRI diagnoses of GIC in the clinic share the problem of low sensitivity. The ineffectiveness of drugs and high recurrence rates in surgical and drug therapies are the main factors that impact the curative effect in GIC patients. Therefore, there is an urgent need to improve diagnostic accuracies and treatment efficiencies. Nanotechnology is widely used in the diagnosis and treatment of GIC by virtue of its unique size advantages and extensive modifiability. In the diagnosis and treatment of clinical GIC, surface-enhanced Raman scattering (SERS) nanoparticles, electrochemical nanobiosensors and magnetic nanoparticles, intraoperative imaging nanoparticles, drug delivery systems and other multifunctional nanoparticles have successfully improved the diagnosis and treatment of GIC. It is important to further improve the coordinated development of nanotechnology and GIC diagnosis and treatment. Herein, starting from the clinical diagnosis and treatment of GIC, this review summarizes which nanotechnologies have been applied in clinical diagnosis and treatment of GIC in recent years, and which cannot be applied in clinical practice. We also point out which challenges must be overcome by nanotechnology in the development of the clinical diagnosis and treatment of GIC and discuss how to quickly and safely combine the latest nanotechnology developed in the laboratory with clinical applications. Finally, we hope that this review can provide valuable reference information for researchers who are conducting cross-research on GIC and nanotechnology.

Plasma–Saline Water Interaction: A Systematic Review

Plasma–liquid interaction research has developed substantially in recent years due, mostly, to the numerous applications of cold atmospheric plasma (CAP). Plasma–liquid interactions are influenced by the concentrations of the ionic species present in the liquid environment, and few studies have paid attention to saline water, which generally mediates the reactions in many plasma applications. Therefore, the present review aims to explore the main results and the influence of variables on the modification of properties of saline water by CAP sources following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The searches were carried out in the Scopus, Science Direct, and Web of Science databases, resulting in the inclusion of 37 studies. The main effects of the interaction between CAP and saline water are (i) the production of reactive oxygen and nitrogen species (RONS); (ii) the increase in conductivity and decrease in pH, directly proportional to the increase in discharge voltage; (iii) and the effective area of interaction and the shortest distance between electrode and solution. Other effects are the localized evaporation and crystallization of salts, which make the interaction between plasma and saline water a promising field in the development of technologies for desalination and improvement of liquid properties.

Simulating the Feasibility of Using Liquid Micro-Jets for Determining Electron–Liquid Scattering Cross-Sections

The extraction of electron–liquid phase cross-sections (surface and bulk) is proposed through the measurement of (differential) energy loss spectra for electrons scattered from a liquid micro-jet. The signature physical elements of the scattering processes on the energy loss spectra are highlighted using a Monte Carlo simulation technique, originally developed for simulating electron transport in liquids. Machine learning techniques are applied to the simulated electron energy loss spectra, to invert the data and extract the cross-sections. The extraction of the elastic cross-section for neon was determined within 9% accuracy over the energy range 1–100 eV. The extension toward the simultaneous determination of elastic and ionisation cross-sections resulted in a decrease in accuracy, now to within 18% accuracy for elastic scattering and 1% for ionisation. Additional methods are explored to enhance the accuracy of the simultaneous extraction of liquid phase cross-sections.

Plasma bioscience for medicine, agriculture and hygiene applications

Nonthermal biocompatible plasma (NBP) sources operating in atmospheric pressure environments and their characteristics can be used for plasma bioscience, medicine, and hygiene applications, especially for COVID-19 and citizen. This review surveyed the various NBP sources, including a plasma jet, micro-DBD (dielectric barrier discharge) and nanosecond discharged plasma. The electron temperatures and the plasma densities, which are produced using dielectric barrier discharged electrode systems, can be characterized as 0.7 ~ 1.8 eV and (3-5) × 1014-15 cm-3, respectively. Herein, we introduce a general schematic view of the plasma ultraviolet photolysis of water molecules for reactive oxygen and nitrogen species (RONS) generation inside biological cells or living tissues, which would be synergistically important with RONS diffusive propagation into cells or tissues. Of the RONS, the hydroxyl radical [OH] and hydrogen peroxide H2O2 species would mainly result in apoptotic cell death with other RONS in plasma bioscience and medicines. The diseased biological protein, cancer, and mutated cells could be treated by using a NBP or plasma activated water (PAW) resulting in their apoptosis for a new paradigm of plasma medicine.

Plasma with carbon nanoparticles: advances and application

This article is devoted to the study of the glow intensity of radio-frequency capacitive discharge plasma with nanoparticles for further use in lighting devices. The process of carbon nanoparticles synthesis in the radiofrequency discharge was investigated, and the influence of plasma parameters on the formation and growth of the material was also studied. A method for determining the diameter of nanoparticles based on self-bias voltage and electron density is considered. It is revealed that the diameter of nanoparticles has a considerable influence on the optical properties of the plasma, in particular, on the emission intensity. Based on the obtained data, laboratory samples of lighting devices with improved luminous intensities were developed.

Plasma bioscience and its application to medicine

Nonthermal atmospheric pressure biocompatible plasma (NBP), alternatively called bio-cold plasma, is a partially ionized gas that consists of charged particles, neutral atoms and molecules, photons, an electric field, and heat. Recently, nonthermal plasma-based technology has been applied to bioscience, medicine, agriculture, food processing, and safety. Various plasma device configurations and electrode layouts has fast-tracked plasma applications in the treatment of biological and material surfaces. The NBP action mechanism may be related to the synergy of plasma constituents, such as ultraviolet radiation or a reactive species. Recently, plasma has been used in the inactivation of viruses and resistant microbes, such as fungal cells, bacteria, spores, and biofilms made by microbes. It has also been used to heal wounds, coagulate blood, degrade pollutants, functionalize material surfaces, kill cancers, and for dental applications. This review provides an outline of NBP devices and their applications in bioscience and medicine. We also discuss the role of plasma-activated liquids in biological applications, such as cancer treatments and agriculture. The individual adaptation of plasma to meet specific medical requirements necessitates real-time monitoring of both the plasma performance and the target that is treated and will provide a new paradigm of plasma-based therapeutic clinical systems.