Plasmas for Treating Cancer: Opportunities for Adaptive and Self-Adaptive Approaches

Cold atmospheric plasma (CAP): a revolutionary approach in dermatology and skincare

Cold atmospheric plasma (CAP) technology has emerged as a revolutionary therapeutic technology in dermatology, recognized for its safety, effectiveness, and minimal side effects. CAP demonstrates substantial antimicrobial properties against bacteria, viruses, and fungi, promotes tissue proliferation and wound healing, and inhibits the growth and migration of tumor cells. This paper explores the versatile applications of CAP in dermatology, skin health, and skincare. It provides an in-depth analysis of plasma technology, medical plasma applications, and CAP. The review covers the classification of CAP, its direct and indirect applications, and the penetration and mechanisms of action of its active components in the skin. Briefly introduce CAP's suppressive effects on microbial infections, detailing its impact on infectious skin diseases and its specific effects on bacteria, fungi, viruses, and parasites. It also highlights CAP's role in promoting tissue proliferation and wound healing and its effectiveness in treating inflammatory skin diseases such as psoriasis, atopic dermatitis, and vitiligo. Additionally, the review examines CAP's potential in suppressing tumor cell proliferation and migration and its applications in cosmetic and skincare treatments. The therapeutic potential of CAP in treating immune-mediated skin diseases is also discussed. CAP presents significant promise as a dermatological treatment, offering a safe and effective approach for various skin conditions. Its ability to operate at room temperature and its broad spectrum of applications make it a valuable tool in dermatology. Finally, introduce further research is required to fully elucidate its mechanisms, optimize its use, and expand its clinical applications.

Enhancement of Biocompatibility of High-Transparency Zirconia Abutments with Human Gingival Fibroblasts via Cold Atmospheric Plasma Treatment: An In Vitro Study

The objective of this study was to explore the effects of cold atmospheric plasma (CAP) treatment on the biological behavior of human gingival fibroblasts (HGFs) cultured on the surface of high-transparency zirconia. Two types of zirconia, 3Y-ZTP and 4Y-PSZ, were subjected to a CAP treatment for various treatment durations. Analyses of the physical and chemical properties of 3Y-ZTP and 4Y-PSZ were conducted using scanning electron microscopy, contact angle measurements, and X-ray photoelectron spectroscopy, both before and after CAP treatment. The biological responses of HGFs on both surfaces were assessed using CCK-8 assay, confocal laser scanning microscopy, and real-time PCR. Initially, the oxygen and hydroxyl contents on the surface of 4Y-PSZ exceeded those on 3Y-ZTP. CAP treatment enhanced the surface hydrophilicity and the reactive oxygen species (ROS) content of 4Y-PSZ, while not altering the surface morphology. After CAP treatment, HGFs' adhesion on 4Y-PSZ was superior, with more pronounced effects compared to 3Y-ZTP. Notably, HGFs counts and the expression of adhesion-related genes on 4Y-PSZ peaked following the CAP exposures for 30 s and 60 s. Consequently, this study demonstrates that, following identical CAP treatments, 4Y-PSZ is more effective in promoting HGFs adhesion compared to traditional 3Y-ZTP zirconia.

Glycosylation editing: an innovative therapeutic opportunity in precision oncology

Cancer is still one of the most arduous challenges in the human society, even though humans have found many ways to try to conquer it. With our incremental understandings on the impact of sugar on human health, the clinical relevance of glycosylation has attracted our attention. The fact that altered glycosylation profiles reflect and define different health statuses provide novel opportunities for cancer diagnosis and therapeutics. By reviewing the mechanisms and critical enzymes involved in protein, lipid and glycosylation, as well as current use of glycosylation for cancer diagnosis and therapeutics, we identify the pivotal connection between glycosylation and cellular redox status and, correspondingly, propose the use of redox modulatory tools such as cold atmospheric plasma (CAP) in cancer control via glycosylation editing. This paper interrogates the clinical relevance of glycosylation on cancer and has the promise to provide new ideas for laboratory practice of cold atmospheric plasma (CAP) and precision oncology therapy.

Plasma-liquid interactions in the presence of organic matter-A perspective

As investigations in the biomedical applications of plasma advance, a demand for describing safe and efficacious delivery of plasma is emerging. It is quite clear that not all plasmas are "equal" for all applications. This Perspective discusses limitations of the existing parameters used to define plasma in context of the need for the "right plasma" at the "right dose" for each "disease system." The validity of results extrapolated from in vitro studies to preclinical and clinical applications is discussed. We make a case for studying the whole system as a single unit, in situ. Furthermore, we argue that while plasma-generated chemical species are the proposed key effectors in biological systems, the contribution of physical effectors (electric fields, surface charging, dielectric properties of target, changes in gap electric fields, etc.) must not be ignored.

Cold atmospheric plasma sensitizes melanoma cells to targeted therapy agents in vitro

Cold atmospheric plasma (CAP) has been reported to kill melanoma cells in vitro and in vivo. BRAF and MEK inhibitors are targeted therapy agents for advanced melanoma patients with BRAF mutations. However, low overall survival and relapse-free survival are still tough challenges due to drug resistance. In this study, we confirmed that CAP alleviated innate drug resistance and promoted the anti-tumor effect of targeted therapy in A875 and WM115 melanoma cells in vitro. Further, we revealed that CAP altered the expression of various molecules concerning MAPK and PI3K-AKT pathways in A875 cells. This study demonstrates that CAP promises to work as adjuvant treatment with targeted therapy to overcome drug resistance for malignant tumors in future.

Comparative assessment of direct and indirect cold atmospheric plasma effects, based on helium and argon, on human glioblastoma: an in vitro and in vivo study

Recent research has highlighted the promising potential of cold atmospheric plasma (CAP) in cancer therapy. However, variations in study outcomes are attributed to differences in CAP devices and plasma parameters, which lead to diverse compositions of plasma products, including electrons, charged particles, reactive species, UV light, and heat. This study aimed to evaluate and compare the optimal exposure time, duration, and direction-dependent cellular effects of two CAPs, based on argon and helium gases, on glioblastoma U-87 MG cancer cells and an animal model of GBM. Two plasma jets were used as low-temperature plasma sources in which helium or argon gas was ionized by high voltage (4.5 kV) and frequency (20 kHz). In vitro assessments on human GBM and normal astrocyte cell lines, using MTT assays, flow cytometry analysis, wound healing assays, and immunocytochemistry for Caspase3 and P53 proteins, demonstrated that all studied plasma jets, especially indirect argon CAP, selectively induced apoptosis, hindered tumor cell growth, and inhibited migration. These effects occurred concurrently with increased intracellular levels of reactive oxygen species and decreased total antioxidant capacity in the cells. In vivo results further supported these findings, indicating that single indirect argon and direct helium CAP therapy, equal to high dose Temozolomide treatment, induced tumor cell death in a rat model of GBM. This was concurrent with a reduction in tumor size observed through PET-CT scan imaging and a significant increase in the survival rate. Additionally, there was a decrease in GFAP protein levels, a significant GBM tumor marker, and an increase in P53 protein expression based on immunohistochemical analyses. Furthermore, Ledge beam test analysis revealed general motor function improvement after indirect argon CAP therapy, similar to Temozolomide treatment. Taken together, these results suggest that CAP therapy, using indirect argon and direct helium jets, holds great promise for clinical applications in GBM treatment.

Cold atmospheric plasma (CAP) treatment increased reactive oxygen and nitrogen species (RONS) levels in tumor samples obtained from patients with low-grade glioma

Low-grade gliomas (LGGs) are a heterogeneous group of tumors with an average 10-year survival rate of 40%-55%. Current treatment options include chemotherapy, radiotherapy, and gross total resection (GTR) of the tumor. The extent of resection (EOR) plays an important role in improving surgical outcomes. However, the major obstacle in treating low-grade gliomas is their diffused nature and the presence of residual cancer cells at the tumor margins post resection. Cold Atmospheric Plasma (CAP) has shown to be effective in targeted killing of tumor cells in various glioma cell lines without affecting non-tumor cells through Reactive Oxygen and Nitrogen Species (RONS). However, no study on the effectiveness of CAP has been carried out in LGG tissues till date. In this study, we applied helium-based CAP on tumor tissues resected from LGG patients. Our results show that CAP is effective in promoting RONS accumulation in LGG tissues when CAP jet parameters are set at 4 kV voltage, 5 min treatment time and 3 lpm gas flow rate. We also observed that CAP jet is more effective in thinner slice preparations of tumor as compared to thick tumor samples. Our results indicate that CAP could prove to be an effective adjunct therapy in glioma surgery to target residual cancer cells to improve surgical outcome of patients with low-grade glioma.

Current Status and Future Trends of Cold Atmospheric Plasma as an Oncotherapy

Cold atmospheric plasma (CAP), a redox modulation tool, is capable of inhibiting a wide spectrum of cancers and has thus been proposed as an emerging onco-therapy. However, with incremental successes consecutively reported on the anticancer efficacy of CAP, no consensus has been made on the types of tumours sensitive to CAP due to the different intrinsic characteristics of the cells and the heterogeneous design of CAP devices and their parameter configurations. These factors have substantially hindered the clinical use of CAP as an oncotherapy. It is thus imperative to clarify the tumour types responsive to CAP, the experimental models available for CAP-associated investigations, CAP administration strategies and the mechanisms by which CAP exerts its anticancer effects with the aim of identifying important yet less studied areas to accelerate the process of translating CAP into clinical use and fostering the field of plasma oncology.

Low temperature plasma suppresses proliferation, invasion, migration and survival of SK-BR-3 breast cancer cells

BACKGROUND

Low temperature plasma (LTP) is a developing field in recent years to play important roles of sterilization, material modification and wound healing. Breast cancer is a common gynecological malignant tumor. Recent studies have shown that LTP is a promising selective anti-cancer treatment. The effect of LTP on breast cancer is still unclear. In this study, We treated breast cancer cell lines with low temperature plasma for different periods of time and analyzed the relevant differences.

METHODS AND RESULTS

SK-BR-3 cell nutrient solution was firstly treated by ACP for 0, 10, 20, 40, 80 and 120 s, which was next used to cultivateSK-BR-3cells for overnight.we found that LTP was able to suppress cell vitality, proliferation, invasion and migration of SK-BR-3 cells. Also, SK-BR-3 apoptosis was induced by LTP in a time-dependent manner.

CONCLUSION

These evidences suggest the negative effect of LTP on malignant development of SK-BR-3 cells, and LTP has the potential clinical application for breast cancer treatment.

Acquired non-thermal plasma resistance mediates a shift towards aerobic glycolysis and ferroptotic cell death in melanoma

AIMS

To gain insights into the underlying mechanisms of NTP therapy sensitivity and resistance, using the first-ever NTP-resistant cell line derived from sensitive melanoma cells (A375).

METHODS

Melanoma cells were exposed to NTP and re-cultured for 12 consecutive weeks before evaluation against the parental control cells. Whole transcriptome sequencing analysis was performed to identify differentially expressed genes and enriched molecular pathways. Glucose uptake, extracellular lactate, media acidification, and mitochondrial respiration was analyzed to determine metabolic changes. Cell death inhibitors were used to assess the NTP-induced cell death mechanisms, and apoptosis and ferroptosis was further validated via Annexin V, Caspase 3/7, and lipid peroxidation analysis.

RESULTS

Cells continuously exposed to NTP became 10 times more resistant to NTP compared to the parental cell line of the same passage, based on their half-maximal inhibitory concentration (IC50). Sequencing and metabolic analysis indicated that NTP-resistant cells had a preference towards aerobic glycolysis, while cell death analysis revealed that NTP-resistant cells exhibited less apoptosis but were more vulnerable to lipid peroxidation and ferroptosis.

CONCLUSIONS

A preference towards aerobic glycolysis and ferroptotic cell death are key physiological changes in NTP-resistance cells, which opens new avenues for further, in-depth research into other cancer types.

Understanding the Role of Plasma Bullet Currents in Heating Skin to Mitigate Risks of Thermal Damage Caused by Low-Temperature Atmospheric-Pressure Plasma Jets

Low-temperature atmospheric-pressure plasma jets are generally considered a safe medical technology with no significant long-term side effects in clinical studies reported to date. However, there are studies emerging that show plasma jets can cause significant side effects in the form of skin burns under certain conditions. Therefore, with a view of developing safer plasma treatment approaches, in this study we have set out to provide new insights into the cause of these skin burns and how to tailor plasma treatments to mitigate these effects. We discovered that joule heating by the plasma bullet currents is responsible for creating skin burns during helium plasma jet treatment of live mice. These burns can be mitigated by treating the mice at a further distance so that the visible plasma plume does not contact the skin. Under these treatment conditions we also show that the plasma jet treatment still retains its medically beneficial property of producing reactive oxygen species in vivo. Therefore, treatment distance is an important parameter for consideration when assessing the safety of medical plasma treatments.

A composition-tunable cold atmospheric plasma chip for multiplex-treatment of cells

Cold atmospheric plasma treatment promises a targeted cancer therapy due to its selectivity and specificity in killing tumor cells. However, the current plasma exposure devices produce diverse and coupled reactive species, impeding the investigation of the underlying plasma-anticancer mechanisms. Also, the limited mono-sample and mono-dosage treatment modality result in tedious and manual experimental tasks. Here, we propose a cold atmospheric plasma chip producing targeted species, delivering multiple dosages, and treating multiple cell lines in a single treatment. Three modules are integrated into the chip. The environment control module and multi-inlet gas-feed module coordinately ignite component-tunable and uniformly distributed plasma. The multi-sample holding module enables multiplex treatment: multi-sample and -dosage treatment with single radiation. By exposing the HepG2 cell line to nitrogen-feed plasmas, we prove the crucial role of nitrogen-based species in inhibiting cell growth and stimulating apoptosis. By loading four-type cell lines on our chip, we can identify the most vulnerable cell line for plasma oncotherapy. Simultaneously, three-level treatment dosages are imposed on the cells with single radiation to optimize the applicable treatment dosage for plasma oncotherapy. Our chip will broaden the design principles of plasma exposure devices, potentially help clarify plasma-induced anticancer mechanisms, and guide the clinical application of plasma-based oncotherapy.

Modulation of the Tumor-Associated Immuno-Environment by Non-Invasive Physical Plasma

Over the past 15 years, investigating the efficacy of non-invasive physical plasma (NIPP) in cancer treatment as a safe oxidative stress inducer has become an active area of research. So far, most studies focused on the NIPP-induced apoptotic death of tumor cells. However, whether NIPP plays a role in the anti-tumor immune responses need to be deciphered in detail. In this review, we summarized the current knowledge of the potential effects of NIPP on immune cells, tumor-immune interactions, and the immunosuppressive tumor microenvironment. In general, relying on their inherent anti-oxidative defense systems, immune cells show a more resistant character than cancer cells in the NIPP-induced apoptosis, which is an important reason why NIPP is considered promising in cancer management. Moreover, NIPP treatment induces immunogenic cell death of cancer cells, leading to maturation of dendritic cells and activation of cytotoxic CD8⁺ T cells to further eliminate the cancer cells. Some studies also suggest that NIPP treatment may promote anti-tumor immune responses via other mechanisms such as inhibiting tumor angiogenesis and the desmoplasia of tumor stroma. Though more evidence is required, we expect a bright future for applying NIPP in clinical cancer management.

Recent advances in cold atmospheric plasma (CAP) for breast cancer therapy

The serious problems of conventional breast cancer therapy strategies such as drug resistance, severe side effects, and lack of selectivity prompted the development of various cold atmospheric plasma (CAP) devices. Due to its advanced technology, CAP can produce a unique environment rich in reactive oxygen and nitrogen species (RONS), photons, charged ions, and an electric field, making it a promising revolutionary platform for cancer therapy. Despite substantial technological successes, CAP-based therapeutic systems are encounter with distinct limitations, including low control of the generated RONS, poor knowledge about its anticancer mechanisms, and challenges concerning designing, manufacturing, clinical translation, and commercialization, which must be resolved. The latest developments in CAP-based therapeutic systems for breast cancer treatment are discussed in this review. More significantly, the integration of CAP-based medicine approaches with other breast cancer therapies, including chemo- and nanotherapy is thoroughly addressed.

Plasma for aquaponics

Global environmental, social, and economic challenges call for innovative solutions to food production. Current food production systems require advances beyond traditional paradigms, acknowledging the complexity arising from sustainability and a present lack of awareness about technologies that may help limit, for example, loss of nutrients from soil. Aquaponics, a closed-loop system that combines aquaculture with hydroponics, is a step towards the more efficient management of scarce water, land, and nutrient resources. However, its large-scale use is currently limited by several significant challenges of maintaining desirable water chemistry and pH, managing infections in fish and plants, and increasing productivity efficiently, economically, and sustainably. This paper investigates the opportunities presented by plasma technologies in meeting these challenges, potentially opening new pathways for sustainability in food production.

Anti-Cancer Activity of the Combinational Treatment of Noozone Cold Plasma with p-FAK Antibody-Conjugated Gold Nanoparticles in OSCC Xenograft Mice

Oral squamous cell cancer (OSCC) is the most common type of oral cancer (about 80–90% of cases) and various research is being done to cure the disease. This paper aims to verify whether treatment with no-ozone cold plasma (NCP), which is designed for safe usage of the plasma on oral cavities, in combination with gold nanoparticles conjugated with p-FAK antibody (p-FAK/GNP) can trigger the selective and instant killing of SCC-25 cells both in vitro and in vivo. When SCC25 and HaCaT cells are exposed to p-FAK/GNP+NCP, the instant cell death was observed only in SCC25 cells. Such p-FAK/GNP+NCP-mediated cell death was observed only when NCP was directly treated on SCC25 harboring p-FAK/GNP. During NCP treatment, the removal of charged particles from NCP using grounded electric mesh radically decreased the p-FAK/GNP+NCP-mediated cell death. This p-FAK/GNP+NCP-mediated selective cell death of OSCC was also observed in mice xenograft models using SCC25 cells. The mere treatment of p-FAK/GNP and NCP on the xenograft tumor slowly decreased the size of the tumor, and only about 50% of the tumor remained at the end of the experiment. On the other hand, 1 week of p-FAK/GNP+NCP treatment was enough to reduce half of the tumor size, and most of tumor tissue had vanished at the end. An analysis of isolated tissues showed that in the case of individual treatment with p-FAK/GNP or NCP, the cancer cell population was reduced due to apoptotic cell death. However, in the case of p-FAK/GNP+NCP, apoptotic cell death was unobserved, and most tissues were composed of collagen. Thus, this paper suggests the possibility of p-FAK/GNP+NCP as a new method for treating OSCC.

Emerging innovations in cold plasma therapy against cancer: A paradigm shift

Cancer is one of the major causes of mortality, accounting for ∼ 9.5 million deaths globally in 2018. The spectrum of conventional treatment for cancer includes surgery, chemotherapy and radiotherapy. Recently, cold plasma therapy surfaced as a novel technique in the treatment of cancer. The FDA approval of the first trial for the use of cold atmospheric plasma (CAP) in cancer therapy in 2019 is evidence of this. This review highlights the mechanisms of action of CAP. Additionally, its applications in anticancer therapy have been reviewed. In summary, this article will introduce the readers to the exciting field of plasma oncology and help them understand the current status and prospects of plasma oncology.

Recognizing Cold Atmospheric Plasma Plume Using Computer Vision

Over the last three decades, cold atmospheric plasma (CAP) has been heavily investigated in a wide range of biological applications, including wound healing, microorganism sterilization, and cancer treatment. Atmospheric pressure plasma jets (APPJs) are the most common plasma sources in plasma medicine. An APPJ’s size determines its application range and approach in treatment. In this study, we demonstrated the real-time recognition of an APPJ’s plasma plume output using computer vision (CV), dramatically improving the measurement speed compared to the traditional method of using the naked eye. Our work provides a framework to monitor an aspect of an APPJ’s performance in real time, which is a necessary step to achieving an intelligent CAP source.

Cold Atmospheric Plasma Targeting Hematological Malignancies: Potentials and Problems of Clinical Translation

Cold atmospheric plasma is an ionized gas produced near room temperature; it generates reactive oxygen species and nitrogen species and induces physical changes, including ultraviolet, radiation, thermal, and electromagnetic effects. Several studies showed that cold atmospheric plasma could effectively provoke death in a huge amount of cell types, including neoplastic cells, via the induction of apoptosis, necrosis, and autophagy. This technique seems able to destroy tumor cells by disturbing their more susceptible redox equilibrium with respect to normal cells, but it is also able to cause immunogenic cell death by enhancing the immune response, to decrease angiogenesis, and to provoke genetic and epigenetics mutations. Solutions activated by cold gas plasma represent a new modality for treatment of less easily reached tumors, or hematological malignancies. Our review reports on accepted knowledge of cold atmospheric plasma’s effect on hematological malignancies, such as acute and chronic myeloid leukemia and multiple myeloma. Although relevant progress was made toward understanding the underlying mechanisms concerning the efficacy of cold atmospheric plasma in hematological tumors, there is a need to determine both guidelines and safety limits that guarantee an absence of long-term side effects.

Plasma Dermatology: Skin Therapy Using Cold Atmospheric Plasma

Cold atmospheric plasma-based plasma medicine has been expanding the diversity of its specialties. As an emerging branch, plasma dermatology takes advantage of the beneficial complexity of plasma constituents (e.g., reactive oxygen and nitrogen species, UV photons, and electromagnetic emission), technical versatility (e.g., direct irradiation and indirect aqueous treatment), and practical feasibility (e.g., hand-held compact device and clinician-friendly operation). The objective of this comprehensive review is to summarize recent advances in the CAP-dominated skin therapy by broadly covering three aspects. We start with plasma optimisation of intact skin, detailing the effect of CAP on skin lipids, cells, histology, and blood circulation. We then conduct a clinically oriented and thorough dissection of CAP treatment of various skin diseases, focusing on the wound healing, inflammatory disorders, infectious conditions, parasitic infestations, cutaneous malignancies, and alopecia. Finally, we conclude with a brief analysis on the safety aspect of CAP treatment and a proposal on how to mitigate the potential risks. This comprehensive review endeavors to serve as a mini textbook for clinical dermatologists and a practical manual for plasma biotechnologists. Our collective goal is to consolidate plasma dermatology’s lead in modern personalized medicine.

Primary cold atmospheric plasma combined with low dose cisplatin as a possible adjuvant combination therapy for HNSCC cells-an in-vitro study

BACKGROUND

The aim of the present study was to examine the cytostatic effects of cold atmospheric plasma (CAP) on different head and neck squamous carcinoma (HNSCC) cell lines either in isolation or in combination with low dose cisplatin. The effect of CAP treatment was investigated by using three different HNSCC cell lines (chemo-resistant Cal 27, chemo-sensitive FaDu and OSC 19).

MATERIALS AND METHOD

Cell lines were exposed to CAP treatment for 30, 60, 90, 120 and 180 s (s). Cisplatin was added concurrently (cc) or 24 h after CAP application (cs). Cell viability, DNA damage and apoptosis was evaluated by dye exclusion, MTT, alkaline microgel electrophoresis assay and Annexin V-Fit-C/PI respectively.

RESULTS

In all cell lines, 120 s of CAP exposure resulted in a significant reduction of cell viability. DNA damage significantly increased after 60 s. Combined treatment of cells with CAP and low dose cisplatin showed additive effects. A possible sensitivity to cisplatin could be restored in Cal 27 cells by CAP application.

CONCLUSION

CAP shows strong cytostatic effects in HNSCC cell lines that can be increased by concurrent cisplatin treatment, suggesting that CAP may enhance the therapeutic efficacy of low dose cisplatin.

Theranostic Potential of Adaptive Cold Atmospheric Plasma with Temozolomide to Checkmate Glioblastoma: An In Vitro Study

Simple Summary

Glioblastoma (GBM) is an aggressive form of brain cancer. Here, we present a combination therapy of cold atmospheric plasma (CAP) and temozolomide (TMZ) to treat GBM in vitro. We analyze the effects of the co-treatment in two GBM (TMZ-resistant and -sensitive) cell lines. The aim of this study is mainly to sensitize these cells using CAP so that they respond well to TMZ. We further found that the removal of cell culture media after CAP treatment does not affect the sensitivity of CAP to cancer cells but enhances the effects of TMZ. However, it was observed in our study that keeping the CAP-treated media for a shorter time did not significantly inhibit T98G cells. Interestingly, keeping the same plasma-treated media for a longer duration resulted in a decrease in cell viability. On the contrary, TMZ-sensitive cell A172 responded well to the co-treatment. This could be a potential reason for the sensitization of the combination therapy.

Abstract

Cold atmospheric plasma (CAP) has been used for the treatment of various cancers. The anti-cancer properties of CAP are mainly due to the reactive species generated from it. Here, we analyze the efficacy of CAP in combination with temozolomide (TMZ) in two different human glioblastoma cell lines, T98G and A172, in vitro using various conditions. We also establish an optimized dose of the co-treatment to study potential sensitization in TMZ-resistant cells. The removal of cell culture media after CAP treatment did not affect the sensitivity of CAP to cancer cells. However, keeping the CAP-treated media for a shorter time helped in the slight proliferation of T98G cells, while keeping the same media for longer durations resulted in a decrease in its survivability. This could be a potential reason for the sensitization of the cells in combination treatment. Co-treatment effectively increased the lactate dehydrogenase (LDH) activity, indicating cytotoxicity. Furthermore, apoptosis and caspase-3 activity also significantly increased in both cell lines, implying the anticancer nature of the combination. The microscopic analysis of the cells post-treatment indicated nuclear fragmentation, and caspase activity demonstrated apoptosis. Therefore, a combination treatment of CAP and TMZ may be a potent therapeutic modality to treat glioblastoma. This could also indicate that a pre-treatment with CAP causes the cells to be more sensitive to chemotherapy treatment.

Insight into the Impact of Oxidative Stress on the Barrier Properties of Lipid Bilayer Models

As a new field of oxidative stress-based therapy, cold physical plasma is a promising tool for several biomedical applications due to its potential to create a broad diversity of reactive oxygen and nitrogen species (RONS). Although proposed, the impact of plasma-derived RONS on the cell membrane lipids and properties is not fully understood. For this purpose, the changes in the lipid bilayer functionality under oxidative stress generated by an argon plasma jet (kINPen) were investigated by electrochemical techniques. In addition, liquid chromatography-tandem mass spectrometry was employed to analyze the plasma-induced modifications on the model lipids. Various asymmetric bilayers mimicking the structure and properties of the erythrocyte cell membrane were transferred onto a gold electrode surface by Langmuir-Blodgett/Langmuir-Schaefer deposition techniques. A strong impact of cholesterol on membrane permeabilization by plasma-derived species was revealed. Moreover, the maintenance of the barrier properties is influenced by the chemical composition of the head group. Mainly the head group size and its hydrogen bonding capacities are relevant, and phosphatidylcholines are significantly more susceptible than phosphatidylserines and other lipid classes, underlining the high relevance of this lipid class in membrane dynamics and cell physiology.

Cold Atmospheric Plasma-Activated Media Improve Paclitaxel Efficacy on Breast Cancer Cells in a Combined Treatment Model

The use of plasma-activated media (PAM), an alternative to direct delivery of cold atmospheric plasma to cancer cells, has recently gained interest in the plasma medicine field. Paclitaxel (PTX) is used as a chemotherapy of choice for various types of breast cancers, which is the leading cause of mortality in females due to cancer. In this study, we evaluated an alternative way to improve anti-cancerous efficiency of PTX by association with PAM, the ultimate achievement being a better outcome in killing tumoral cells at smaller doses of PTX. MCF-7 and MDA-MB-231 cell lines were used, and the outcome was measured by cell viability (MTT assay), the survival rate (clonogenic assay), apoptosis occurrence, and genotoxicity (COMET assay). Treatment consisted of the use of PAM in combination with under IC50 doses of PTX in short- and long-term models. The experimental data showed that PAM had the capacity to improve PTX's cytotoxicity, as viability of the breast cancer cells dropped, an effect maintained in long-term experiments. A higher frequency of apoptotic, dead cells, and DNA fragmentation was registered in cells treated with the combined treatment as compared with those treated only with PT. Overall, PAM had the capacity to amplify the anti-cancerous effect of PTX.

Cold Plasma Discharge Tube Enhances Antitumoral Efficacy of Temozolomide

Glioblastoma (GBM) is a fatal human brain tumor with a low survival rate. Temozolomide (TMZ) has been widely used in GBM therapy with noticeable side effects. Cold plasma is an ionized gas that is generated near room temperature. Here, we demonstrated the enhancement therapeutic efficacy of TMZ via using a cold plasma source based on nonequilibrium plasma in a sealed glass tube, named a radial cold plasma discharge tube (PDT). The PDT affected glioblastoma cells' function just by its electromagnetic (EM) emission rather than any chemical factors in the plasma. The PDT selectively increased the cytotoxicity of TMZ on two typical glioblastoma cell lines, U87MG and A172, compared with normal astrocyte cell line hTERT/E6/E7 to some extent. Furthermore, on the basis of a patient-derived xenograft model, our preliminary in vivo studies demonstrated the drastically improved mean survival days of the tumor-barrier mice by more than 100% compared to control. The PDT is not only independent of continuous helium supply but is also capable of resisting the interference of environmental changes. Thus, the PDT was a stable and low-cost cold atmospheric plasma source. In short, this study is the first to demonstrate the promising application of PDTs in GBM therapy as a noninvasive and portable modality.

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.

Cold Atmospheric Plasma Attenuates Breast Cancer Cell Growth Through Regulation of Cell Microenvironment Effectors

Breast cancer exists in multiple subtypes some of which still lack a targeted and effective therapy. Cold atmospheric plasma (CAP) has been proposed as an emerging anti-cancer treatment modality. In this study, we investigated the effects of direct and indirect CAP treatment driven by the advantageous nanosecond pulsed discharge on breast cancer cells of different malignant phenotypes and estrogen receptor (ER) status, a major factor in the prognosis and therapeutic management of breast cancer. The main CAP reactive species in liquid (i.e. H2O2, NO2−/NO3−) and gas phase were determined as a function of plasma operational parameters (i.e. treatment time, pulse voltage and frequency), while pre-treatment with the ROS scavenger NAC revealed the impact of ROS in the treatment. CAP treatment induced intense phenotypic changes and apoptosis in both ER+ and ER- cells, which is associated with the mitochondrial pathway as evidenced by the increased Bax/Bcl-2 ratio and cleavage of PARP-1. Interestingly, CAP significantly reduced CD44 protein expression (a major cancer stem cell marker and matrix receptor), while differentially affected the expression of proteases and inflammatory mediators. Collectively, the findings of the present study suggest that CAP suppresses breast cancer cell growth and regulates several effectors of the tumor microenvironment and thus it could represent an efficient therapeutic approach for distinct breast cancer subtypes.

Multi-Modal Biological Destruction by Cold Atmospheric Plasma: Capability and Mechanism

Cold atmospheric plasma (CAP) is a near-room-temperature, partially ionized gas composed of reactive neutral and charged species. CAP also generates physical factors, including ultraviolet (UV) radiation and thermal and electromagnetic (EM) effects. Studies over the past decade demonstrated that CAP could effectively induce death in a wide range of cell types, from mammalian to bacterial cells. Viruses can also be inactivated by a CAP treatment. The CAP-triggered cell-death types mainly include apoptosis, necrosis, and autophagy-associated cell death. Cell death and virus inactivation triggered by CAP are the foundation of the emerging medical applications of CAP, including cancer therapy, sterilization, and wound healing. Here, we systematically analyze the entire picture of multi-modal biological destruction by CAP treatment and their underlying mechanisms based on the latest discoveries particularly the physical effects on cancer cells.

Inactivation of Acanthamoeba Cysts in Suspension and on Contaminated Contact Lenses Using Non-Thermal Plasma

Water suspensions of cysts of a pathogenic clinical isolate of Acanthamoeba sp. were prepared, and the cysts were inactivated either in suspension or placed on the surface of contact lenses by the non-thermal plasma produced by the DC corona transient spark discharge. The efficacy of this treatment was determined by cultivation and the presence of vegetative trophozoites indicating non-inactivated cysts. The negative discharge appeared to be more effective than the positive one. The complete inactivation occurred in water suspension after 40 min and on contaminated lenses after 50 min of plasma exposure. The properties of lenses seem to not be affected by plasma exposure; that is, their optical power, diameter, curvature, water content and infrared and Raman spectra remain unchanged.

Cold atmospheric plasma selectively induces G0/G1 cell cycle arrest and apoptosis in AR-independent prostate cancer cells

Purpose: Androgen receptor-independent prostate cancers do not respond to androgen blockage therapies and suffer from high recurrence rate. We aim to contribute to the establishment of novel therapeutic approaches against such malignancies.

Materials and Methods: We examined whether and how cold atmospheric plasma delivers selectivity against AR-independent prostate cancers via cell viability, transwell assay, wound healing, cell apoptosis assay, flow cytometry, intracellular hydrogen peroxide determination assay, RONS scavenger assay and western blot using human normal epithelial prostatic cells PNT1A and AR-negative DU145 prostate cancer cells.

Results: We show that cold atmospheric plasma could selectively halt cell proliferation and migration in androgen receptor-independent cells as a result of induced cell apoptosis and G0/G1 stage cell cycle arrest, and such outcomes were achieved through modulations on the MAPK and NF-kB pathways in response to physical plasma induced intracellular redox level.

Conclusion: Our study reports cold atmospheric plasma induced reduction on the proliferation and migration of androgen receptor-independent prostate cancer cells that offers novel therapeutic insights on the treatment of such cancers, and provides the first evidence on physical plasma induced cell cycle G0/G1 stage arrest that warrants the exploration on the synergistic use of cold atmospheric plasma and drugs such as chemotherapies in eradicating such cancer cells.

Selectivity of direct plasma treatment and plasma-conditioned media in bone cancer cell lines

Atmospheric pressure plasma jets have been shown to impact several cancer cell lines, both in vitro and in vivo. These effects are based on the biochemistry of the reactive oxygen and nitrogen species generated by plasmas in physiological liquids, referred to as plasma-conditioned liquids. Plasma-conditioned media are efficient in the generation of reactive species, inducing selective cancer cell death. However, the concentration of reactive species generated by plasma in the cell culture media of different cell types can be highly variable, complicating the ability to draw precise conclusions due to the differential sensitivity of different cells to reactive species. Here, we compared the effects of direct and indirect plasma treatment on non-malignant bone cells (hOBs and hMSCs) and bone cancer cells (SaOs-2s and MG63s) by treating the cells directly or exposing them to previously treated cell culture medium. Biological effects were correlated with the concentrations of reactive species generated in the liquid. A linear increase in reactive species in the cell culture medium was observed with increased plasma treatment time independent of the volume treated. Values up to 700 µM for H2O2 and 140 µM of NO2- were attained in 2 mL after 15 min of plasma treatment in AdvDMEM cell culture media. Selectivity towards bone cancer cells was observed after both direct and indirect plasma treatments, leading to a decrease in bone cancer cell viability at 72 h to 30% for the longest plasma treatment times while maintaining the survival of non-malignant cells. Therefore, plasma-conditioned media may represent the basis for a potentially novel non-invasive technique for bone cancer therapy.

Cold Atmospheric Plasma Cancer Treatment, a Critical Review

Cold atmospheric plasma (CAP) is an ionized gas, the product of a non-equilibrium discharge at atmospheric conditions. Both chemical and physical factors in CAP have been demonstrated to have unique biological impacts in cancer treatment. From a chemical-based perspective, the anti-cancer efficacy is determined by the cellular sensitivity to reactive species. CAP may also be used as a powerful anti-cancer modality based on its physical factors, mainly EM emission. Here, we delve into three CAP cancer treatment approaches, chemically based direct/indirect treatment and physical-based treatment by discussing their basic principles, features, advantages, and drawbacks. This review does not focus on the molecular mechanisms, which have been widely introduced in previous reviews. Based on these approaches and novel adaptive plasma concepts, we discuss the potential clinical application of CAP cancer treatment using a critical evaluation and forward-looking perspectives.

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.

Cold atmospheric plasma induced genotoxicity and cytotoxicity in esophageal cancer cells

In this paper, we studied the functional effects of cold atmospheric plasma (CAP) on the esophageal cancer cell line (KYSE-30) by direct and indirect treatment and fibroblast cell lines as normal cells. KYSE-30 cells were treated with CAP at different time points of 60, 90, 120 and, 240 s for direct exposure and 90, 180, 240 and, 360 s for indirect exposure. Cell viability was studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and apoptosis induction in the treated cells was measured by Annexin-V/PI using flow cytometry. The expression of apoptotic related genes (BAX/BCL-2) was analyzed by real-time polymerase chain reaction. Moreover, the genotoxicity was analyzed by comet assay. Cell viability results showed that direct CAP treatment has a markedly cytotoxic impact on the reduction of KYSE-30 cells at 60 s (p = 0.000), while indirect exposure was less impactful (p > 0.05). The results of the Annexin-V/PI staining confirmed this analysis. Subsequently, the genotoxicity study of the direct CAP treatment demonstrated a longer tail-DNA length and caused increase in DNA damage in the cells (p < 0.00001) as well as shift BAX/BCL-2 toward apoptosis. The concentration of H₂O₂ and NO₂^- in direct CAP treatment was significantly higher than indirect (p > 0.05). Treatment with direct CAP showed genotoxicity in cancer cells. Collectively, our results pave a deeper understanding of CAP functions and the way for further investigations in the field of esophageal cancer treatment.

Inactivation of Schistosoma Using Low-Temperature Plasma

The inactivation of Schistosoma mansoni cercariae and miracidia was achieved by exposure to plasma produced by the positive, negative, and axial negative corona discharges. The positive discharge appeared as the most effective, causing the death of cercariae and miracidia within 2-3 min of exposure. The negative discharge was less effective, and the axial discharge was ineffective. The water pre-activated (PAW) by the discharges showed similar efficiency, with the exception of the significantly effective PAW activated with axial discharge. These facts, together with the observation of various reactions among plasma-damaged schistosomes, suggest that the mechanisms of inactivation by different types of discharges are different.

Cold Atmospheric Plasma: A Promising Controller of Cancer Cell States

Simple Summary

Cancer treatment is complicated by the distinct phenotypic attractor states in which cancer cells exist within individual tumors, and inherent plasticity of cells in transiting between these states facilitates the acquisition of drug-resistant and more stem cell-like phenotypes in cancer cells. Controlling these crucial transition switches is therefore critical for the long-term success of any cancer therapy. This paper highlights the most promising avenues for controlling cancer state transition events by cold atmospheric plasma (CAP) to enable the development of efficient tools for cancer prevention and management. The key switches in carcinogenesis can be used to halt or reverse cancer progression, and understanding how CAP can modulate these processes is critical for the development of CAP-based strategies for cancer prevention, detection and effective treatment.

Abstract

Rich in reactive oxygen and nitrogen species, cold atmospheric plasma has been shown to effectively control events critical to cancer progression; selectively inducing apoptosis, reducing tumor volume and vasculature, and halting metastasis by taking advantage of, e.g., synergies between hydrogen peroxide and nitrites. This paper discusses the efficacy, safety and administration of cold atmospheric plasma treatment as a potential tool against cancers, with a focus on the mechanisms by which cold atmospheric plasma may affect critical transitional switches that govern tumorigenesis: the life/death control, tumor angiogenesis and epithelial–mesenchymal transition, and drug sensitivity spectrum. We introduce the possibility of modeling cell transitions between the normal and cancerous states using cold atmospheric plasma as a novel research avenue to enhance our understanding of plasma-aided control of oncogenesis.

Advances in Plasma Oncology toward Clinical Translation

This Special Issue on "Advances in Plasma Oncology Toward Clinical Translation" aims to bring together cutting-edge research papers within the field in the context of clinical translation and application [...].

Cold Atmospheric Pressure Plasma (CAP) as a New Tool for the Management of Vulva Cancer and Vulvar Premalignant Lesions in Gynaecological Oncology

Vulvar cancer (VC) is a specific form of malignancy accounting for 5–6% of all gynaecologic malignancies. Although VC occurs most commonly in women after 60 years of age, disease incidence has risen progressively in premenopausal women in recent decades. VC demonstrates particular features requiring well-adapted therapeutic approaches to avoid potential treatment-related complications. Significant improvements in disease-free survival and overall survival rates for patients diagnosed with post-stage I disease have been achieved by implementing a combination therapy consisting of radical surgical resection, systemic chemotherapy and/or radiotherapy. Achieving local control remains challenging. However, mostly due to specific anatomical conditions, the need for comprehensive surgical reconstruction and frequent post-operative healing complications. Novel therapeutic tools better adapted to VC particularities are essential for improving individual outcomes. To this end, cold atmospheric plasma (CAP) treatment is a promising option for VC, and is particularly appropriate for the local treatment of dysplastic lesions, early intraepithelial cancer, and invasive tumours. In addition, CAP also helps reduce inflammatory complications and improve wound healing. The application of CAP may realise either directly or indirectly utilising nanoparticle technologies. CAP has demonstrated remarkable treatment benefits for several malignant conditions, and has created new medical fields, such as “plasma medicine” and “plasma oncology”. This article highlights the benefits of CAP for the treatment of VC, VC pre-stages, and postsurgical wound complications. There has not yet been a published report of CAP on vulvar cancer cells, and so this review summarises the progress made in gynaecological oncology and in other cancers, and promotes an important, understudied area for future research. The paradigm shift from reactive to predictive, preventive and personalised medical approaches in overall VC management is also considered.

Model for deformation of cells from external electric fields at or near resonant frequencies

This paper presents a numerical model to investigate the deformation of biological cells by applying external electric fields operating at or near cell resonant frequencies. Cells are represented as pseudo solids with high viscosity suspended in liquid media. The electric field source is an atmospheric plasma jet developed inhouse, for which the emitted energy distribution has been measured. Viscoelastic response is resolved in the entire cell structure by solving a deformation matrix assuming an isotropic material with a prescribed modulus of elasticity. To investigate cell deformation at resonant frequencies, one mode of natural cell oscillation is considered in which the cell membrane is made to radially move about its eigenfrequency. An electromagnetic wave source interacts with the cell and induces oscillation and viscoelastic response. The source carries energy in the form of a distribution function which couples a range of oscillating frequencies with electric field amplitudes. Results show that cell response may be increased by the external electric field operating at or near resonance. In the elastic regime, response increases until a steady threshold value, and the structure moves as a damped oscillator. Generally, this response is a function of both frequency and magnitude of the source, with a maximum effect found at resonance. To understand the full effect of the source energy spectrum, the system is solved by considering five frequency-amplitude couplings. Results show that the total solution is a nonlinear combination of the individual solutions. Additionally, sources with different signal phases are simulated to determine the effect of initial conditions on the evolution of the system, and the result suggests that there may be multiple solutions within the same order of magnitude for elastic response and velocity. Cell rupture from electric stress may occur during application given a high energy source.

Plasma-activated medium as adjuvant therapy for lung cancer with malignant pleural effusion

This study compared effects of plasma-activated medium (PAM) with effects of conventional clinical thermal therapy on both lung cancer cells and benign cells for management of malignant pleural effusion (MPE). For MPE treatment, chemotherapy, photodynamic therapy, and thermal therapy are used but caused systemic side effects, patient photosensitivity, and edema, respectively. Recent studies show that plasma induces apoptosis in cancer cells with minor effects on normal cells and is cost-effective. However, the effects of plasma on MPE have not been investigated previously. This study applied a nonthermal atmospheric-pressure plasma jet to treat RPMI medium to produce PAM, carefully controlled the long-life reactive oxygen and nitrogen species concentration in PAM, and treated the cells. The influence of PAM treatment on the microenvironment of cells was also checked. The results indicated that PAM selectively inhibited CL1–5 and A549 cells, exerting minor effects on benign mesothelial and fibroblast cells. In contrast to selective lethal effects of PAM, thermal therapy inhibited both CL1–5 and benign mesothelial cells. This study also found that fibroblast growth factor 1 is not the factor explaining why PAM can selectively inhibit CL1–5 cells. These results indicate that PAM is potentially a less-harmful and cost-effective adjuvant therapy for MPE.

Inactivation of Dermatophytes Causing Onychomycosis and Its Therapy Using Non-Thermal Plasma

Onychomycosis is one of the most common nail disorders. Its current treatment is not satisfactorily effective and often causes adverse side effects. This study aims to determine the optimal conditions for non-thermal plasma (NTP) inactivation of the most common dermatophytes in vitro and to apply it in patient`s therapy. The in vitro exposure to NTP produced by negative DC corona discharge caused full inactivation of Trichophyton spp. if applied during the early growth phases. This effect decreased to negligible inactivation with the exposure applied six days after inoculation. In a group of 40 patients with onychomycosis, NTP therapy was combined with nail plate abrasion and refreshment (NPAR) or treatment with antimycotics. The cohort included 17 patients treated with NPAR combined with NTP, 11 patients treated with antimycotics and NTP, and 12 patients treated with NPAR alone. The combination of NPAR and NTP resulted in clinical cure in more than 70% of patients. The synergistic effect of NPAR and NTP caused 85.7% improvement of mycological cure confirmed by negative microscopy and culture of the affected nail plate. We conclude that NTP can significantly improve the treatment of onychomycosis.

Combination therapy of cold atmospheric plasma (CAP) with temozolomide in the treatment of U87MG glioblastoma cells

Cold atmospheric plasma (CAP) technology, a relatively novel technique mainly investigated as a stand-alone cancer treatment method in vivo and in vitro, is being proposed for application in conjunction with chemotherapy. In this study, we explore whether CAP, an ionized gas produced in laboratory settings and that operates at near room temperature, can enhance Temozolomide (TMZ) cytotoxicity on a glioblastoma cell line (U87MG). Temozolomide is the first line of treatment for glioblastoma, one of the most aggressive brain tumors that remains incurable despite advancements with treatment modalities. The cellular response to a single CAP treatment followed by three treatments with TMZ was monitored with a cell viability assay. According to the cell viability results, CAP treatment successfully augmented the effect of a cytotoxic TMZ dose (50 μM) and further restored the effect of a non-cytotoxic TMZ dose (10 μM). Application of CAP in conjunction TMZ increased DNA damage measured by the phosphorylation of H2AX and induced G2/M cell cycle arrest. These findings were supported by additional data indicating reduced cell migration and increased αvβ3 and αvβ5 cell surface integrin expression as a result of combined CAP–TMZ treatment. The data presented in this study serve as evidence that CAP technology can be a suitable candidate for combination therapy with existing chemotherapeutic drugs. CAP can also be investigated in future studies for sensitizing glioblastoma cells to TMZ and other drugs available in the market.

Cold Atmospheric Plasma Treatment for Pancreatic Cancer-The Importance of Pancreatic Stellate Cells

Simple Summary

This review aims to highlight the potential of cold plasma, the fourth state of matter, as anti-cancer treatment for pancreatic cancer, and the importance of pancreatic stellate cells in the response to this treatment. Currently, a significant lack of basic research on cold plasma considering both pancreatic cancer and stellate cells exists. However, co-cultures of these populations can be advantageous, as they resemble the cell-to-cell interactions occurring in a tumor in response to therapy. Even more, these studies should be performed prior to clinical trials of cold plasma to avoid unforeseen responses to treatment. This review article provides a framework for future research of cold plasma therapies for pancreatic cancer, considering the critical role of pancreatic stellate cells in the disease and treatment outcome.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with low five-year survival rates of 8% by conventional treatment methods, e.g., chemotherapy, radiotherapy, and surgery. PDAC shows high resistance towards chemo- and radiotherapy and only 15–20% of all patients can have surgery. This disease is predicted to become the third global leading cause of cancer death due to its significant rise in incidence. Therefore, the development of an alternative or combinational method is necessary to improve current approaches. Cold atmospheric plasma (CAP) treatments could offer multiple advantages to this emerging situation. The plasma-derived reactive species can induce oxidative damage and a cascade of intracellular signaling pathways, which could lead to cell death. Previous reports have shown that CAP treatment also influences cells in the tumor microenvironment, such as the pancreatic stellate cells (PSCs). These PSCs, when activated, play a crucial role in the propagation, growth and survival of PDAC tumors. However, the effect of CAP on PSCs is not yet fully understood. This review focuses on the application of CAP for PDAC treatment and the importance of PSCs in the response to treatment.

Critical Analysis of Non-Thermal Plasma-Driven Modulation of Immune Cells from Clinical Perspective

The emerged field of non-thermal plasma (NTP) shows great potential in the alteration of cell redox status, which can be utilized as a promising therapeutic implication. In recent years, the NTP field considerably progresses in the modulation of immune cell function leading to promising in vivo results. In fact, understanding the underlying cellular mechanisms triggered by NTP remains incomplete. In order to boost the field closer to real-life clinical applications, there is a need for a critical overview of the current state-of-the-art. In this review, we conduct a critical analysis of the NTP-triggered modulation of immune cells. Importantly, we analyze pitfalls in the field and identify persisting challenges. We show that the identification of misconceptions opens a door to the development of a research strategy to overcome these limitations. Finally, we propose the idea that solving problems highlighted in this review will accelerate the clinical translation of NTP-based treatments.

A Physically Triggered Cell Death via Transbarrier Cold Atmospheric Plasma Cancer Treatment

Cold atmospheric plasma (CAP) is a near room-temperature ionized gas composed of highly reactive species. CAP also generates thermal radiation, ultraviolet radiation, and electromagnetic (EM) waves. So far, nearly all biological effects of CAP have relied on the chemical factors in CAP. Here, we first show that the EM emission from CAP can lead to the death of melanoma cells via a transbarrier contactless method. Compared with reactive species, the effect of the physical factors causes much stronger growth inhibition on a reactive species-resistant melanoma cell line B16F10. Such a physically triggered growth inhibition is due to a new cell death type, characterized by the rapid leakage of bulk solutions from the cells, resulting in cytoplasm shrinkage and bubbling on the cell membrane. The physically based CAP-triggered cell death can occur even there is a macroscale gap between the bulk CAP and cells, which includes an air gap (∼8 mm) and a dielectric material of the dish or plate (∼1 mm). Either a too large or a too small gap will inhibit such cell death. The physically triggered cellular pressure may cause the bubbling on cells, which can be inhibited in a hypotonic environment via the extracellular osmotic pressure. This study builds a foundation to use CAP as a physically based noninvasive cancer treatment.

The anti-glioblastoma effect of cold atmospheric plasma treatment: physical pathway v.s. chemical pathway

Cold atmospheric plasma (CAP), a near room temperature ionized gas, has shown potential application in many branches of medicine, particularly in cancer treatment. In previous studies, the biological effect of CAP on cancer cells and other mammalian cells has been based solely on the chemical factors in CAP, particularly the reactive species. Therefore, plasma medicine has been regarded as a reactive species-based medicine, and the physical factors in CAP such as the thermal effect, ultraviolet irradiation, and electromagnetic effect have been regarded as ignorable factors. In this study, we investigated the effect of a physical CAP treatment on glioblastoma cells. For the first time, we demonstrated that the physical factors in CAP could reinstate the positive selectivity on CAP-treated astrocytes. The positive selectivity was a result of necrosis, a new cell death in glioblastoma cells characterized by the leak of bulk water from the cell membrane. The physically-based CAP treatment overcomed a large limitation of the traditional chemically based CAP treatment, which had complete dependence on the sensitivity of cells to reactive species. The physically-based CAP treatment is a potential non-invasive anti-tumor tool, which may have wide application for tumors located in deeper tissues.

Recent advances in the implant-based drug delivery in otorhinolaryngology

The surgical implant is an interdisciplinary therapeutic modality that offers unique advantages in the daily practice of otorhinolaryngology. Some well-known examples include cochlear implants, bone-anchored hearing aids, sinus stents, and tracheostomy tubes. Neuroprotective, osteogenic, anti-inflammatory, and antimicrobial effects are among their established or pursued functions. Implant-based drug delivery affords an efficient and potent approach to enhancing these therapeutic functions. Recent innovations have infiltrated all four elements of a drug-eluting implant. The purpose of this pre-clinical, biotechnology-oriented review is to discuss these developments in terms of the implant biomaterial, loaded medication, delivery pattern, and system fabrication. Cell-mediated neurotrophin release, fabrication of a hydroxyapatite-supported system, biodegradable polymer-based implants, and multiclass and multidrug delivery are some representative advancements. The ultimate goal here is to bridge the gap between biotechnology advances and clinical needs. The review is concluded with a perspective regarding the future opportunities and challenges in this popular and rapidly developing subject of research. STATEMENT OF SIGNIFICANCE: Surgical implants and local drug delivery are representative modern modalities of surgical treatment and medical treatment, respectively. Their synergy offers unique therapeutic advantages, such as minimal systemic side effects, proximity-related high efficiency, and potential absorbability. The applications of implant-based drug delivery have infiltrated otorhinolaryngology and head & neck surgery, which is well known for its related tissue diversity and surgical complexity. Examples discussed here include cochlear implants, bone-anchored hearing aids, sinus stents, and airway tubes. This timely review focuses primarily on the four fundamental components of an implant-based drug delivery system, namely implant biomaterial, loaded medication, delivery pattern, and system fabrication. A particular emphasis is placed upon the in vitro cellular and in vivo animal studies that demonstrate pre-clinical potentials.