Cold Atmospheric Plasma Research Articles

Comprehensive studies on the biological activities of human metastatic (MDA-MB-231) and non-metastatic (MCF-7) breast cancer cell lines, directly or combinedly treated using non-thermal plasma-based approaches

Progressive incidence and a pessimistic survival rate of breast cancer in women worldwide remains one of the most concerning topics. Progressing research indicates a potentially high effectiveness of use cold atmospheric plasma (CAP) systems. The undoubted advantage seems its simplicity in combination with other anti-cancer modalities. Following observed trend of studies, one inventory CAP system was applied to directly treat human breast cancer cell lines and culturing in two different Plasma Activated Media (PAM) for combined utilization. Proposed CAP treatments on MCF-10 A, MCF-7, and MDA-MB-231 cell lines were studied in terms of impact on cell viability by MTT assay. Disturbances in cell motility following direct and combined CAP application were assessed by scratch test. Finally, the induction of apoptosis and necrosis was verified with annexin V and propidium iodide staining. Reactive species generated during CAP treatment were determined based on optical emission spectrometry analysis along with colorimetric methods to qualitatively assess the NO2−, NO3−, H2O2, and total ROS with free radicals concentration. The most effective approach for CAP utilization was combined treatment, leading to significant disruption in cell viability, motility and mostly apoptosis induction in breast cancer cell lines. Determined CAP dose allows for mild outcome, showing insignificant harm for the non-cancerous MCF-10 A cell line, while the highly aggressive MDA-MB-231 cell line shows the highest sensitivity on proposed CAP treatment. Direct CAP treatment seems to drive the cells into the sensitive state in which the effectiveness of PAM is boosted. Observed anti-cancer response of CAP treatment was mostly triggered by RNS (mostly NO2− ions) and ROS along with free radicals (such as H2O2, OH•, O2-•, 1O2, HO2•). The combined application of one CAP source represent a promising alternative in the development of new and effective modalities for breast cancer treatment.

In-vitro biofilm removal from TiUnite® implant surface with an air polishing and two different plasma devices

BackgroundWe investigated the efficacy of two different cold atmospheric pressure jet plasma devices (CAP09 and CAPmed) and an air polishing device with glycine powder (AP) either applied as monotherapies or combined therapies (AP + CAP09; AP + CAPmed), in microbial biofilm removal from discs with anodised titanium surface.MethodsDiscs covered with 7-day-old microbial biofilm were treated either with CAP09, CAPmed, AP, AP + CAP09 or AP + CAPmed and compared with negative and positive controls. Biofilm removal was assessed with flourescence and electron microscopy immediately after treatment and after 5 days of reincubation of the treated discs.ResultsTreatment with CAP09 or CAPmed did not lead to an effective biofilm removal, whereas treatment with AP detached the complete biofilm, which however regrew to baseline magnitude after 5 days of reincubation. Both combination therapies (AP + CAP09 and AP + CAPmed) achieved a complete biofilm removal immediately after cleaning. However, biofilm regrew after 5 days on 50% of the discs treated with the combination therapy.ConclusionAP treatment alone can remove gross biofilm immediately from anodised titanium surfaces. However, it did not impede regrowth after 5 days, because microorganisms were probably hidden in holes and troughs, from which they could regrow, and which were inaccessible to AP. The combination of AP and plasma treatment probably removed or inactivated microorganisms also from these hard to access spots. These results were independent of the choice of plasma device.

Biomedical Applications of Cold Atmospheric Plasma: Cancer Therapy and Virus Inactivation

Cold atmospheric plasma (CAP), known for its ability to generate Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS), has emerged as a promising tool in many biomedical applications, including cancer therapeutics and virus inactivation. In cancer therapy, ROS and RNS induced by plasma have been shown to selectively target cancer cells, triggering apoptosis and inhibiting tumor growth while sparing healthy cells. This selective cytotoxicity makes plasma an attractive option for localized cancer treatment with minimal side effects. Additionally, the antimicrobial properties of ROS and RNS make plasma an effective agent for virus inactivation. By connecting the dots between cancer therapy and virus disinfection, this review paper sheds light on the potential of plasma-generated ROS and RNS as versatile tools in medical applications, offering a dual benefit of targeted cancer treatment and effective virus control. Specifically, this review explores the effects of CAP treatment on B16 melanoma cells, assessing changes in cell viability, proliferation, apoptosis and oxidative stress response. Dichloroacetate (DCA), a mitochondrial modulator, has shown promise in inducing apoptosis in melanoma cells. However, its clinical use is limited by side effects related to its neurotoxicity and suspected carcinogenicity. The potential of CAP in enhancing the therapeutic efficacy of DCA on B16-F10 melanoma apoptosis is also explored. CAP therapeutics for other types of cancers are also explored in this review. Alongside its implications in oncology, CAP has gathered substantial attention for its extraordinary potential in neutralizing viruses. CAP’s exceptional precision in targeting viral envelopes, genetic material and structural components disrupts their integrity and vital functions. This orchestrated mechanism offers a swift and efficacious route to render viruses inactive, encompassing both enveloped and nonenveloped viral types. In parallel pursuit, this review examines CAP-generated reactive species’ proficiency in deactivating SARS-CoV-2 across various surfaces. The inquiry entails subjecting surfaces to CAP treatment, succeeded by quantifying viral load and scrutinizing viral integrity. The outcomes gleaned from these investigations provide pivotal insights into CAP’s potential as a robust surface disinfection strategy, poised to combat the propagation of viral transmission.

Emerging Alternaria toxins present in naturally contaminated dried tomatoes and their reduction using cold atmospheric plasma

This study investigated the efficacy of cold atmospheric plasma (CAP) treatment in degrading the emerging Alternaria toxins as pure molecules and as natural contaminants in dried tomatoes. The analyses of 25 batches of dried tomatoes showed that more than 40% of samples were contaminated with tenuazonic acid (TeA), one with Alternariol (AOH), while Tentoxin (TEN), Alternariol monomethyl ether (AME) and Altenuene (ALT) were not detected. CAP under ozone (O3) and NOx regimes were used to reduce the mycotoxin contamination, the results shown that O3 regime was more effective against all mycotoxins tested, while NOx regime showed different efficacy depending on the specific mycotoxin. The Weibull model proved to be appropriate for the degradation kinetics of all Alternaria toxins, regardless of the kinetic order they possess. Under the O3 regime, the resistance of the mycotoxin was AME > AOH > TEN > TeA > ALT. Our studies have shown for the first time that CAP reduces Alternaria toxins in naturally contaminated dried tomatoes. In particular, the rate of degradation under O3 regime increased significantly with the longest exposure time, reaching 52.80 ± 1.21 % of mycotoxin degradation. Our results expand our knowledge of CAP treatment as a potential means of reducing mycotoxin contamination in food. Further studies will be carried out to investigate the potential mycotoxin degradation products and to ensure food safety.

Exploring the Influence of Cold Plasma on Epidermal Melanogenesis In Situ and In Vitro.

Epidermal melanin synthesis determines an individual's skin color. In humans, melanin is formed by melanocytes within the epidermis. The process of melanin synthesis strongly depends on a range of cellular factors, including the fine-tuned interplay with reactive oxygen species (ROS). In this context, a role of cold atmospheric plasma (CAP) on melanin synthesis was proposed due to its tunable ROS generation. Herein, the argon-driven plasma jet kINPen® MED was employed, and its impact on melanin synthesis was evaluated by comparison with known stimulants such as the phosphodiesterase inhibitor IBMX and UV radiation. Different available model systems were employed, and the melanin content of both cultured human melanocytes (in vitro) and full-thickness human skin biopsies (in situ) were analyzed. A histochemical method detected melanin in skin tissue. Cellular melanin was measured by NIR autofluorescence using flow cytometry, and a highly sensitive HPLC-MS method was applied, which enabled the differentiation of eu- and pheomelanin by their degradation products. The melanin content in full-thickness human skin biopsies increased after repeated CAP exposure, while there were only minor effects in cultured melanocytes compared to UV radiation and IBMX treatment. Based on these findings, CAP does not appear to be a useful option for treating skin pigmentation disorders. On the other hand, the risk of hyperpigmentation as an adverse effect of CAP application for wound healing or other dermatological diseases seems to be neglectable.

Influence of Biofilm Maturity on the Antibacterial Efficacy of Cold Atmospheric Plasma in Oral Microcosm Biofilms.

As biofilms mature, biomass and extracellular polysaccharide (EPS) content increases, enhancing pathogenicity. Therefore, this study aimed to evaluate the antibacterial efficacy of cold atmospheric plasma (CAP) against oral microcosm biofilms and the influence of biofilm maturity on treatment. Oral microcosm biofilms were cultured on hydroxyapatite disks for 2 and 6 days. Based on the treatment and biofilm maturity, these were subsequently allocated into six groups (N = 19 each): Groups 1 and 2 were incubated with distilled water for 1 min; Groups 3 and 4 were treated with CAP for 2 min, and Groups 5 and 6 were treated with 0.12% chlorhexidine gluconate for 1 min. Groups 1, 3, and 5 represent 2-day biofilms, and Groups 2, 4, and 6 represent 6-day biofilms. Treatments were repeated daily for 5 days. Antibacterial efficacy was analyzed by measuring oral biofilms' red fluorescence intensity (RatioR/G) and quantifying EPS content and bacterial viability. The RatioR/G was 1.089-fold and 1.104-fold higher in Groups 4 and 6 than in Groups 3 and 5 following antibacterial treatment, respectively (p < 0.001). EPS content increased by 1.71-fold in Group 6 than in Group 5 (p < 0.001). Bacterial survival rate was the lowest in Group 3 (p = 0.005). These findings underscore the relevance of CAP treatment in maintaining antibacterial efficacy regardless of the biofilm development stage, highlighting its potential utility in oral care.

Biocompatible plasma-treated liquids: A sustainable approach for decontaminating gastrointestinal-infection causing pathogens

Nosocomial infections are a serious threat and difficult to cure due to rising antibiotic resistance in pathogens and biofilms. Direct exposure to cold atmospheric plasma (CAP) has been widely employed in numerous biological research endeavors. Nonetheless, plasma-treated liquids (PTLs) formulated with physiological solutions may offer additional benefits such as enhanced portability, and biocompatibility. Additionally, CAP-infused long-lived reactive oxygen and nitrogen species (RONS) such as nitrite (NO2−), nitrate (NO3−), and hydrogen peroxide (H2O2) can synergistically induce their antibacterial activity. Herein, we investigated those argon-plasma jet-treated liquids, including Ringer’s lactate (RL), phosphate-buffered saline (PBS), and physiological saline, have significant antibacterial activity against nosocomial/gastrointestinal-causing pathogens, which might be due to ROS-mediated lipid peroxidation. Combining the conventional culture-based method with propidium iodide monoazide quantitative PCR (PMAxx™-qPCR) indicated that PTLs induce a minimal viable but non-culturable (VBNC) state and moderately affect culturable counts. Specifically, the PTL exposure resulted in pathogenicity dysfunction via controlling T3SS-related effector genes of S. enterica. Overall, this study provides insights into the effectiveness of PTLs for inducing ROS-mediated damage, controlling the virulence of diarrheagenic bacteria, and modulating homeostatic genes.

Plasma water treatment for PFAS: Study of degradation of perfluorinated substances and their byproducts by using cold atmospheric pressure plasma jet

This study evaluates the effectiveness of non-thermal plasma at atmospheric pressure (NTP APPJ) for treating PFAS - contaminated water in different matrices. Successful removal of several perfluoroalkyl carboxylic acids (PFCAs) (C6 to C4), perfluroalkane sulfonic acids (PFSAs) (C8 to C4) and perfluropolyethers (PFPEs) (GenX and ADONA) PFAS compounds was achieved in laboratory scale experiments. In the deionized water (DW), high removal efficiencies (> 90%) were observed for longer-chain PFAS, PFOS (99.89%), PFHxA (94.61%) and ADONA (94.83%), while shorter- chain compounds had lower removal rates. Real water samples (tap water and synthetic effluent) showed lower overall degradation percentages (8–50%) depending on compound and matrix. Short-chain PFAS displayed around 10% removal in tap water, while PFOS and GenX achieved 50% and 32% removal, respectively. Complex matrix effects influence degradation rates. Byproducts from the plasma treatment were investigated, revealing distinct degradation mechanisms for various PFAS compounds. For PFSAs and PFCAs, degradation involved electron transfer, bond breaking and subsequent reactions. Conversely, ADONA and GenX degradation initiated with ether-group cleavage, followed by additional transformation processes. Plasma-based technology shows potential for degradation of PFAS, especially for newer substitute compounds like ADONA and GenX. However, further research is needed to optimize plasma performance for complete mineralization of PFAS. This study also proposes a degradation mechanism for ADONA, marking a novel investigation into ether-group PFAS degradation with potential implications for further research and understanding toxicological implications.

Multiparameter optimization of non-thermal plasma-driven synthesis of carbohydrate-stabilized rhenium nanoparticles towards enhancement of their catalytical activity for reduction of nitroaromatic compounds

This study aims to optimize the synthesis of carbohydrate-stabilized rhenium nanoparticles (ReNPs) utilizing cold atmospheric pressure plasma (CAPP), specifically direct current atmospheric pressure glow discharge (dc-APGD), hypothesizing that controlling synthesis parameters will enhance catalytic efficiency in the reduction of nitroaromatic compounds (NACs). The dc-APGD system operated in flowing liquid cathode (FLC-dc-APGD) and flowing liquid anode (FLA-dc-APGD) modes. Design of experiments (DOE) and response surface methodology (RSM) were employed for the first time to optimize ReNPs synthesis by adjustment of the concentration of ReO4- in ReNPs precursor solution, its flow rate, as well as the discharge current. ReNPs were characterized using high-resolution transmission electron microscopy (HRTEM), dynamic light scattering (DLS), and X-Ray photoelectron spectroscopy (XPS). In turn, optical emission spectroscopy (OES) was employed for the identification of reactive species generated in the plasma phase that contributed to the synthesis of ReNPs. The resultant sizes, surface charges, and phase compositions were linked with synthesis parameters and then with catalytic activities revealed by the variety of ReNPs. HRTEM photomicrographs showed spherical and spherical-like morphologies of the obtained ReNPs synthesized using FLC-dc-APGD and FLA-dc-APGD modes with the actual sizes of 7.28 ± 2.90 nm and 3.24 ± 0.57 nm, respectively. The optimized conditions yielded ReNPs of exceptional catalytic activity, that reduced 94.9 % (FLC-dc-APGD) and 90.5 % (FLA-dc-APGD) of 4-nitrophenol (4-NP) with the apparent rate constants (k1) 0.269 and 0.107 min−1, respectively. Further, the conversions of 90 % were achieved over FLC-dc-APGD-based ReNPs for nitrobenzene (NB), 2,4,6-trinitrophenol (2,4,6-TNP), 2,4-dinitrophenol (2,4-DNP), and 4-nitroaniline (4-NA). In these cases, the k1 values were 0.235, 0.174, 0.070, 0.001 min−1, respectively. The results allowed to find a correlation between ReNP size distribution, oxidation state, and catalytic activity that suggested a potential for tailored Re nanocatalysts in environmental remediation.

Assessment of Food Processing Technologies on Allergen Reduction in United States

Purpose: The aim of the study was to analyze the assessment of food processing technologies on allergen reduction in United States. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: Recent advancements in food processing technologies in the U.S. are focusing on reducing allergenicity in food products. Thermal methods are traditionally used, but novel nonthermal techniques, such as high-pressure processing and cold atmospheric plasma, are now being explored for their potential to create hypoallergenic products. These methods aim to modify allergenic proteins without using heat, which can preserve food quality while reducing allergen reactivity. Despite these advancements, ensuring the complete removal of allergens remains challenging, highlighting the ongoing need for robust detection and control strategies​. Unique Contribution to Theory, Practice and Policy: Risk assessment theory, health belief model (HBM) &amp; diffusion of innovations theory may be used to anchor future studies on analyze the assessment of food processing technologies on allergen reduction in United States. Implementing advanced food processing technologies focused on allergen reduction can revolutionize industry practices. Regulatory bodies could use empirical data from these assessments to set more precise guidelines and safety standards for allergen levels in food products.

Machine learning-aided evaluation of oxidative strength of cold atmospheric plasma-treated water.

Plasma medicine is gaining attraction in the medical field, particularly the use of cold atmospheric plasma (CAP) in biomedicine. The chemistry of the plasma is complex, and the reactive oxygen species (ROS) within it are the basis for the biological effect of CAP on the target. Understanding how the oxidative power of ROS responds to diverse plasma parameters is vital for standardizing the effective application of CAP. The proven applicability of machine learning (ML) in the field of medicine is encouraging, as it can also be applied in the field of plasma medicine to correlate the oxidative strength of plasma-treated water (PTW) according to different parameters. In this study, plasma-treated water was mixed with potassium iodide-starch reagent for color formation that could be linked to the oxidative capacity of PTW. Corresponding images were captured resulting from the exposure of the color-forming agent to water treated with plasma for different time points. Several ML models were trained to distinguish the color changes sourced by the oxidative strength of ROS. The AdaBoost Classifier (ABC) algorithm demonstrated better performance among the classification models used by extracting color-based features from the images. Our results, with a test accuracy of 63.5%, might carry a potential for future standardization in the field of plasma medicine with an automated system that can be created to interpret the oxidative properties of ROS in different plasma treatment parameters via ML.

Effects of Cold Atmospheric Pressure Plasma on Streptococcus mutans isolated from Dental Caries

A total of (40) oral cavity swabs were sampled from various sites of dental caries (pit, fissure and dental roots) from patients who referred to the Dental Clinic at the College of Dentistry, Aliraqia University, Baghdad, Iraq. Initially, the swabs were placed in test tubes supplied with Stuart transport medium and then distributed by streaking on semi-selective Mitis Salivaris agar medium (MSA). The findings indicated that the isolates are gram-positive cocci that are arranged in chains. The isolates were further morphologically and biochemically identified, using the VITEK instrument, revealing only 32.5 % (n= 13) of S. mutans. The nonthermal plasma (cold atmospheric pressure plasma; CAP) has many uses in the area of research and development of clinical application worldwide. According to the biofilm assay, all isolates showed the capability of producing biofilm, with differences in thickness of the formed layer, with 3 isolates (7.5%) forming a strong layer, 6 (15%) forming a moderate layer, and 4 (10%) forming a weak layer. The non-thermal plasma (cold atmospheric pressure plasma; CAP) has many uses in the area of research and development of clinical application worldwide.

Cold Atmospheric Pressure Plasma-Activated Medium Modulates Cellular Functions of Human Mesenchymal Stem/Stromal Cells In Vitro.

Cold atmospheric pressure plasma (CAP) offers a variety of therapeutic possibilities and induces the formation of reactive chemical species associated with oxidative stress. Mesenchymal stem/stromal cells (MSCs) play a central role in tissue regeneration, partly because of their antioxidant properties and ability to migrate into regenerating areas. During the therapeutic application, MSCs are directly exposed to the reactive species of CAP. Therefore, the investigation of CAP-induced effects on MSCs is essential. In this study, we quantified the amount of ROS due to the CAP activation of the culture medium. In addition, cell number, metabolic activity, stress signals, and migration were analyzed after the treatment of MSCs with a CAP-activated medium. CAP-activated media induced a significant increase in ROS but did not cause cytotoxic effects on MSCs when the treatment was singular and short-term (one day). This single treatment led to increased cell migration, an essential process in wound healing. In parallel, there was an increase in various cell stress proteins, indicating an adaptation to oxidative stress. Repeated treatments with the CAP-activated medium impaired the viability of the MSCs. The results shown here provide information on the influence of treatment frequency and intensity, which could be necessary for the therapeutic application of CAP.

Electric field and higher harmonics of RF plasma slit jet measured by antennas and VI probes

The cold atmospheric plasma jets change their character when interacting with the different surfaces. Since such interaction is the primary area of plasma jet applications, it is essential to monitor the process. The non-linearity of the RF plasma slit jet (PSJ) was analyzed using the VI probes and a novel method, the non-intrusive antenna measurements. Regardless of the experimental setup and gas mixture (Ar, Ar/O2, Ar/N2), the PSJ frequency spectrum consisted of the following main features: dominant fundamental frequency peak, relatively strong odd harmonics, and significantly weaker even harmonics. The lowest degree of non-linearity was recorded for the Ar PSJ ignited against a grounded target. Admixing a molecular gas increased the discharge non-linearity. It was attributed to the enhancement of secondary electron emission from the dielectric surfaces. In addition to the non-linearity analysis, the antenna spectra were for the first time used to determine the semi-quantitative values of the PSJ-radiated electric field. The electric fields decreased by a factor of 2 after the admixing of nitrogen and oxygen molecular gases. Out of the studied targets, the highest electric fields were observed when plasma impinged on the grounded targets, followed by the floating target (2× lower) and the PSJ ignited in the open space configuration (4× lower than in the grounded target configuration).

Modification of Staphylococcal aureus quorum sensing and virulence factor expression by cold plasma treatment

Abstract Staphylococcal aureus (S. aureus) resides in biofilms and produces virulence factors. Cold atmospheric plasma treatment can be used to kill and reduce bacteria virulence expression. This study will observe the effects of cold plasma treatment on S. aureus killing, biofilm disruption, virulence factor, and quorum sensing gene expression in vitro and in vivo. S. aureus biofilms were grown in vitro on discs and then treated with plasma (J-Plasma; Apyx Medical Inc.) CFU counts, Crystal Violet Staining, and SEM were conducted to determine biofilm disruption and killing. Gene expression was determined by qPCR for Superoxide dismutase (SodA), Panton-Valentine Leukocidin (luk-PV), alpha-hemolysin (Hla), and AgrB and SarA. A similar study was performed on muscles infected in a rat model, treated and untreated, at Days 0, 4 and 14. Cold plasma-treated biofilms on discs had significantly less bacterial CFU counts, lower crystal violet absorbance, and visible disturbances of biofilm. qPCR showed a significant reduction of virulence factor and quorum signaling genes. In vivo, all day 4 and 14 muscle samples had significantly higher CFU counts than 6-hour samples. Results showed a fold change reduction after plasma treatment in virulence and quorum sensing gene expression. Cold plasma treatment disrupts S. aureus biofilm formation and gene expression, both in vivo and in vitro, highlighting the potential of cold plasma treatment to aid in the clearance of S. aureus infections.

In vitro study of cold atmospheric plasma-activated liquids inhibits malignant melanoma by affecting macrophage polarization through the ROS/JAK2/STAT1 pathway

Melanoma is a prevalent malignant skin tumor known for its high invasive ability and a high rate of metastasis, making clinical treatment exceptionally challenging. Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment and play a crucial role in tumor survival and development. Cold atmospheric plasma (CAP) is an emerging tool for tumor treatment that has garnered attention from scholars due to its interaction with non-tumor cells in the tumor microenvironment. Here, we used the macrophage lines THP-1 and RAW264.7, as well as the melanoma cell lines A375 and MV3, as research subjects to investigate the effect of plasma-activated liquid (PAL) on macrophage differentiation and its inhibitory effect on melanoma cell proliferation. We confirmed that the killing effect of PAL on melanoma cells was selective. Using flow cytometry and PCR, we discovered that PAL can influence macrophage differentiation. Through in vitro cell coculture, we demonstrated that PAL-treated macrophages can significantly impede tumor cell development and progression, and the effect is more potent than that of PAL directly targeting tumor cells. Furthermore, we have proposed the hypothesis that PAL promotes the differentiation of macrophages into the M1 type through the ROS/JAK2/STAT1 pathway. To test the hypothesis, we employed catalase and fludarabine to block different sites of the pathway. The results were then validated through Western Blot, qPCR and ELISA. This study illustrates that PAL therapy is an effective tumor immunotherapy and expands the scope of tumor immunotherapy. Furthermore, these findings establish a theoretical foundation for potential clinical applications of PAL.

Use of Cold Plasma in the Treatment of Infected Wounds

The fact that chronic and complex wounds are a serious problem, both for those affected and for the health care system, has been known for decades. Most chronic wounds can be healed through targeted treatment of the cause of the wound and optimal wound care. This includes not only phase-adapted modern wound care, but also, in particular, preparation for surgical coverage. The correct preparation of the wound bed, also known as conditioning, plays an important role in this. In recent years, the use of Cold Atmospheric Plasma (CAP) has emerged as a promising new option. Here, the wound is regularly treated with a partially ionized gas. According to studies, this active gas mixture has antimicrobial properties and promotes wound healing by activating cell regenerative processes. To test the efficacy of cold plasma therapy, for complex hard to heel wound with difficult conditions, 40 patients with 41 wounds were included in a retrospective, multicenter observational trial in Italy. The wounds were complex wounds of different genesis that had been present for at least 2 months (&gt; 60 days) were treated with cold atmospheric plasma, generated with the CE approved handheld plasma device plasma care®. The treatment, as an add on to standard wound therapy, was performed once a week and for 1 Minute per treated wound area for an intervention period of 4 weeks. In the intervention period, a total of 41 wounds from 40 patients were treated and measured. Two patients left the trial, the others showed an average wound size reduction of 28% within 30 days. Of all wounds, two were completely closed at the end and 10 wounds even achieved a reduction of at least 40%. Analyzed by initial wound size, 43% of wounds smaller than 18 cm² reduction of 40 %. No improvement or worsening of the wound size was only observed in five wounds. The observational trial showed a reduction in the bacterial load and accelerated wound healing. In addition to the bacterial load, improved wound bed conditioning was also demonstrated. Cold plasma therapy is well suited for locally targeted application to promote wound healing. It is an uncomplicated and quickly applicable method with no known side effects or risks at present.

Improved Wound Healing by Direct Cold Atmospheric Plasma Once or Twice a Week: A Randomized Controlled Trial on Chronic Venous Leg Ulcers.

Objective: This study compared the effect of two frequencies of direct cold atmospheric plasma (direct-CAP) treatment with standard of care (SOC) alone on healing of venous leg ulcers (VLUs). Approach: Open-label, randomized controlled trial (ClinicalTrials.gov NCT04922463) on chronic VLUs at two home care organizations in the Netherlands. All three groups received SOC for 12 weeks or until healing. In addition, treatment groups received direct-CAP once (1× direct-CAP) or twice (2× direct-CAP) a week, at specialized wound care facilities and the patients' residences. Primary outcome was percentage of wounds healed. Secondary outcomes included wound area reduction and adverse events. Results: In total, 46 patients were randomly allocated to receive SOC only (n = 15), SOC + direct-CAP once a week (n = 17), or SOC + direct-CAP twice a week (n = 14). A higher percentage of wounds healed within 12 weeks in the treatment groups 53.3% (1× direct-CAP, p = 0.16) and 61.5% (2× direct-CAP, p = 0.08) versus 25.0% (control). The largest wound area reduction was obtained with 2× direct-CAP (95.2%, p = 0.07), followed by 1× direct-CAP (63.9%, p = 0.58), versus control (52.8%). Absolute wound area reduced significantly compared with baseline in both treatment groups (p ≤ 0.001), not in control (p = 0.11). No device-related serious adverse events occurred. Innovation: Direct-CAP applied once or twice a week could substantially improve wound healing of VLUs in primary care. Conclusion: Together with other clinical safety and efficacy data, these results support the integration of direct-CAP as a valuable therapy for complex wounds.

Improving functionality and texturization potential of novel pennycress (Thlaspi arvense) protein by inducing polymerization

Pennycress protein isolate (PcPI) has inferior gelation and water holding properties compared to market leader soy protein, preventing its use in food applications such as meat analogues. Therefore, this work aimed to induce polymerization of PcPI by either cold atmospheric plasma (CAP) or transglutaminase (TG) to improve functionality and texturization potential. Micro-compounding was utilized to determine bench-scale texturization potential of unmodified, CAP, and TG modified PcPI hydrated at 50% moisture. CAP treatment following dielectric barrier discharge (DBD) induced polymerization primarily through disulfide linkages. Whereas, TG resulted in a relatively higher extent of polymerization induced by disulfide linkages and other covalent interactions involving mostly cruciferin acidic subunits. Compared to unmodified PcPI, the gel strength doubled and tripled post CAP and TG treatments, respectively. TG treatment caused a significant increase in water holding capacity by 20%. Unmodified PcPI did not form fibrous structures upon micro-compounding, instead it formed a soft mass with low resilience and cohesiveness. CAP modified PcPI (PcPI-CP) had the lowest water holding properties, which resulted in a relatively hard (significantly highest mechanical energy), dense fibrous structures. Due to high gelation strength and water holding capacity, TG modified PcPI (PcPI-TG) resulted in less dense fibrous structures with more air incorporation (significantly higher void %) relative to PcPI control and PcPI-CP. PcPI-TG texturized mass had significantly higher chewiness that is desirable for meat analogues. This research, for the first time, confirmed the potential success of induced polymerization of PcPI, especially with TG, in enhancing gelation and texturization potential.

Rheological and gelling properties of atmospheric pressure cold plasma treated finger millet (Eleusine coracana) starch

Interest in exploring alternative starch sources like finger millet is rising due to wide starch applications. However, native starch often lacks desired qualities, including rheological properties. Modification is thus necessary for specific end uses. Plasma treatment as a greener and sustainable method for starch modification was therefore, studied for its ability to impact rheological properties of finger millet starch (FMS). Considerable changes in the rheological properties on FMS was noted, a significant decrease and increase (p < 0.05) in the peak viscosity (from 3.35 to 0.553 Pa.s) and paste clarity respectively was observed, indicating occurrence of depolymerization. However, intermediate plasma-treated samples (200 V) observed a decrease in paste clarity attributed to aggregate formation and cross-linking. Cross-linking was also confirmed by findings of frequency sweep where a continuous decrease in G’ values of plasma treated FMS gel was interrupted by sudden increase. Despite depolymerization causing alteration of rheological behaviour such as decrease in shear thinning properties, gel strength observed a contradictory increase. This was attributed to incorporation of functional group and absence of shear responsible for network formation giving higher gel strength to FMS gels. This is elaborated in detail in the study. The study thus concluded that cold plasma significantly impacted all the rheological properties of the FMS and hence can prove to be beneficial for modification of starch rheological parameters.