Cold Atmospheric Plasma Treatment Research Articles

Decitabine combined with cold atmospheric plasma induces pyroptosis via the ROS/Caspase-3/GSDME signaling pathway in Ovcar5 cells

BackgroundHigh methylation of the DFNA5 gene results in the absence of GSDME, a key protein that mediates pyroptosis, while decitabine demethylates the DFNA5 gene, resulting in high expression of the GSDME protein. Cold atmospheric plasma (CAP) is a novel anti-cancer method that induces tumor cell death. MethodsThe pyroptosis induced by decitabine in combination with CAP in Ovcar5 cells was evaluated. In particular, mitochondrial membrane potential was estimated by JC-1 staining, dehydrogenase (LDH) release was assessed by ELISA, Annexin V/PI staining was detected by flow cytometry, the cell cycle changes were evaluated using PI staining followed by detection by flow cytometry, and Caspase-9 cleavage, Caspase-3 cleavage and GSDME expression were evaluated by western blot. ResultsDecitabine resulted in high expression of the GSDME in Ovcar5 in a concentration-dependent manner and increased tumor cell sensitivity to CAP. CAP induced mitochondrial damage and activated the Caspase-9/Caspase-3 pathway. Therefore, decitabine combined with CAP induced Ovcar5 cell pyroptosis through Caspase-3 mediated GSDME cleavage. Reactive oxygen species (ROS) generated by CAP treatment played an important role in the CAP/decitabine combination-induced production of ROS, activation of Caspase-9/Caspase-3, GSDME cleavage and pyroptosis that ROS scavenger NAC inhibited all these processes. ConclusionsCAP combined with decitabine induced Caspase-3 activation, which cleaved decitabine-upregulated GSDME and ediated pyroptosis.

Cold Atmospheric Plasma Improves the Colonization of Titanium with Primary Human Osteoblasts: An In Vitro Study.

Several studies have shown that cold atmospheric plasma (CAP) treatment can favourably modify titanium surfaces to promote osteoblast colonization. The aim of this study was to investigate the initial attachment of primary human osteoblasts to plasma-treated titanium. Micro-structured titanium discs were treated with cold atmospheric plasma followed by the application of primary human osteoblasts. The microwave plasma source used in this study uses helium as a carrier gas and was developed at the Leibniz Institute for Surface Modification in Leipzig, Germany. Primary human osteoblasts were analyzed by fluorescence and cell biological tests (alkaline phosphatase activity and cell proliferation using WST-1 assay). The tests were performed after 4, 12, and 24 h and showed statistically significant increased levels of cell activity after plasma treatment. The results of this study indicate that plasma treatment improves the initial attachment of primary human osteoblasts to titanium. For the first time, the positive effect of cold atmospheric plasma treatment of micro-structured titanium on the initial colonization with primary human osteoblasts has been demonstrated. Overall, this study demonstrates the excellent biocompatibility of micro-structured titanium. The results of this study support efforts to use cold atmospheric plasmas in implantology, both for preimplantation conditioning and for regeneration of lost attachment due to peri-implantitis.

Inactivation of lipase and lipoxygenase in whole wheat flour using atmospheric cold plasma and steam treatments: Kinetics, mechanism, and impact on its compositional properties

This study aims to utilize two separate techniques, viz., atmospheric cold plasma (voltage: 5–25 kV; time: 1–10 min) and steam treatments (at 100 °C for 1–4 min), to inactivate lipase and lipoxygenase in whole wheat flour (WWF) and assess the impact on its compositional properties. The cold plasma exposure of WWF at 25 kV/6 min resulted in 97.5% and 100% inactivation in lipase and lipoxygenase activity, respectively, whereas corresponding inactivation values after the steam treatment (100 °C/4 min) were 90.6% and 99.7%. The inactivation order (n) of lipase and lipoxygenase during cold plasma treatment was 1.2 and 1.0, respectively. In the optical emission spectra of cold plasma-induced air, the band heads within 328–426 nm confirmed the transition between various reactive nitrogen species (second positive, first negative, second positive, and mono-positive systems). The band-head for OH radicals was recorded at 314 nm. The oxygen molecular band at 739 nm and singlet oxygen transition line at 778 nm were also observed. The cold plasma and steam treatments resulted in a more random coil in lipase's secondary structure. The cold plasma treatment at 25 kV/6 min didn't impact the particle size, density, color profile, and proximate composition of the flour.

Integrated in-package treatment of hydrogen peroxide and cold plasma for microbial inactivation of cabbage slices.

The efficacy of an in-package microbial inactivation method, combining H2O2 and atmospheric dielectric barrier discharge cold plasma (ADCP) treatments (H2O2-ADCP), in reducing contamination of Brassica oleracea (cabbage) slices was investigated. Cabbage slices were placed in a polyethylene terephthalate container with a H2O2-soaked polypropylene pad attached to the inside of the lid, followed by subjecting the closed container to ADCP treatment. The H2O2-ADCP treatment inactivated Escherichia coli O157:H7 and Listeria monocytogenes, resulting in reductions of 1.8 and 2.0 log CFU/g, respectively, which were greater than the sum of the inactivation effects observed with each individual treatment. The combined treatment decreased the count of Bacillus cereus spores and indigenous bacteria by 1.0 log spores/g and 1.3 log CFU/g, respectively. Moreover, the in-package method did not alter the moisture content or texture of cabbage slices. These results demonstrate the potential of H2O2-ADCP as a microbial decontamination method for packaged cabbage slices.

Survival of Listeria Strains and Shelf Life Determination of Fresh Blueberries (Vaccinium corymbosum) Treated with Cold Atmospheric Plasma.

Fresh blueberries are delicate, hand-picked, packaged, and refrigerated fruits vulnerable to spoilage and contamination. Cold atmospheric plasma (CAP) is a promising antimicrobial technology; therefore, this study evaluated the CAP treatment effect on acid-tolerant Listeria innocua and Listeria monocytogenes and evaluated changes in the quality of the treated fruit. Samples were spot-inoculated with pH 5.5 and 6.0 acid-adapted Listeria species. Samples were treated with gliding arc CAP for 15, 30, 45, and 60 s and evaluated after 0, 1, 4, 7, and 11 days of storage at 4 °C and 90% humidity for the following quality parameters: total aerobic counts, yeast and molds, texture, color, soluble solids, pH, and titratable acidity. CAP treatments of 30 s and over demonstrated significant reductions in pathogens under both the resistant strain and pH conditions. Sixty-second CAP achieved a 0.54 Log CFU g-1 reduction in L. monocytogenes (pH 5.5) and 0.28 Log CFU g-1 for L. monocytogenes (pH 6.0). Yeast and mold counts on day 0 showed statistically significant reductions after 30, 45, and 60 s CAP with an average 2.34 Log CFU g-1 reduction when compared to non-CAP treated samples. Quality parameters did not show major significant differences among CAP treatments during shelf life. CAP is an effective antimicrobial treatment that does not significantly affect fruit quality.

Cold atmospheric plasma stabilizes mismatch repair for effective, uniform treatment of diverse colorectal cancer cell types

Mismatch Repair (MMR) mechanisms play a pivotal role in rectifying DNA replication errors and maintaining the stability of DNA microsatellite structure. Colorectal cancer (CRC) can be characterized into microsatellite stability (MSS) and microsatellite instability (MSI) subtypes based on the functionality of MMR. MSI CRC notably exhibits enhanced chemotherapy resistance, attributable to diminished MMR-related protein expression. Cold atmospheric plasma (CAP) has emerged as a promising treatment modality, demonstrating efficacy in inducing apoptosis in various cancer cells. However, the therapeutic impact of CAP on MSI colorectal cancer, and the underlying mechanisms remain elusive. In this study, we investigated the effects of CAP on MSI (MC38, HCT116, and LOVO) and MSS (CT26 and HT29) CRC cell lines. We are probing into the products of CAP treatment. Our findings indicate that CAP treatment induces comparable effects on apoptosis, reactive oxygen species (ROS), and reactive nitrogen species (RNS), as well as the expression of apoptosis-related proteins in both MSI and MSS cells. Mechanistically, CAP treatment led to an elevation in the expression of mismatch repair proteins (MLH1 and MSH2), particularly in MSI cells, which notably have been proven to facilitate the activation of apoptosis-related proteins. Collectively, our study reveals that CAP enhances apoptotic signaling and induces apoptosis in MSI colorectal cancer cells by upregulating the expression of MMR-related proteins, thereby reinforcing MMR stabilization.

Mechanism of improving the digestibility of coconut globulin by atmospheric cold plasma treatment: The perspective of protein structure

As a natural emulsifier in coconut milk, coconut globulin (CG) is a potential plant-based protein source to replace animal protein. However, due to its poor solubility and poor digestive properties, CG is not sufficiently utilized. The aim of this study was to improve the digestibility of CG by employing atmospheric cold plasma (ACP) technology. The influence of ACP treatment on the digestive properties of coconut globulin was evaluated by measurements of digestibility, degree of hydrolysis, free amino acids (FAAs), and polypeptide distribution after gastrointestinal digestion. These results implied that application of ACP treatment facilitated the digestion of CG, resulting in the hydrolysis of the compound into numerous smaller peptides (<1000 Da) and FAAs. The quartz crystal microbalance with dissipation technique was utilized to monitor the dynamic digestion process of CG. The results observed that ACP-treated CG had increased affinity for pepsin and trypsin, especially at 60 kV (the adsorbed mass was 7.60 μg/cm2). Various analytical techniques, including circular dichroism spectroscopy, Fourier transform infrared spectroscopy, fluorescence spectroscopy, and particle size distribution, demonstrated that ACP treatment facilitated the structural unfold of CG, resulting in increased exposure of enzyme binding sites and hydrolysis into smaller fragments. In addition, in vitro and cell-based antioxidant experiments provided evidence of the significant antioxidant activity of the hydrolysate derived from ACP-treated CG. Hence, the utilization of ACP treatment at 60 kV emerged as the optimal approach for enhancing the digestibility of CG (from 71.65% to 78.65%). This finding provides a theoretical basis for the use of ACP treatment in protein-rich foods, thereby providing insights for expanding the application of ACP treatment in the field of food processing.

Investigating the effect of cold atmospheric plasma treatment on the microbial load of raw potato slices.

Potatoes (Solanum tuberosum), as starchy plants, have been highly esteemed for their rich supply of nutrients. Numerous studies have investigated the potential health benefits of potatoes and explored potential solutions. Among these considerations, the discussion regarding microbial contaminants has remained an important topic. The present study used cold atmospheric plasma (CAP) to evaluate the microbial quality (including mesophilic and psychrotrophic bacteria and mold and yeasts) of raw potato slices during a 14-day storage period. To achieve this goal, the duration of CAP exposure was set at 5, 10, and 15 min, utilizing an electric voltage of 60 kV and a specific frequency of 20 kHz. The findings revealed the effectiveness of CAP pre-treatment in inhibiting microbial growth over the 14 days when compared to the control sample (untreated sample), with a statistically significant difference (P < 0.05). Moreover, with an extension of the CAP exposure duration to 15 min, there was a significant reduction in the logarithmic count of mesophilic, psychrotrophic microorganisms, molds, and yeasts (4.95, 2.85, and 2.22CFU/g, respectively) in comparison to the control groups (7.5, 5.62, and 5.5CFU/g) on days 0, 7, and 14 of the storage periods (P < 0.05). The results of this study highlight the potential of CAP pre-treatment on reducing the microbial load in raw potato slices prior to frying, which could potentially influence the overall quality of potato-based products.

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.

Combined of plasma-activated water and dielectric barrier discharge atmospheric cold plasma treatment improves the characteristic flavor of Asian sea bass (Lates calcarifer) through facilitating lipid oxidation

To explore the combination effects of plasma-activated water and dielectric barrier discharge (PAW-DBD) cold plasma treatment on the formation of volatile flavor and lipid oxidation in Asian sea bass (ASB), the volatile flavor compounds and lipid profiles were characterized by gas chromatography-ion mobility spectrometry and LC-MS-based lipidomics analyses. In total, 38 volatile flavor compound types were identified, and the PAW-DBD group showed the most kinds of volatile components with a significant (p < 0.05) higher content in aldehydes, ketones, and alcohols. A total of 1500 lipids was detected in lipidomics analysis, phosphatidylcholine was the most followed by triglyceride. The total saturated fatty acids content in PAW-DBD group increased by 105.02 μg/g, while the total content of unsaturated fatty acids decreased by 275.36 μg/g. It can be concluded that the PAW-DBD processing increased both the types and amounts of the volatile flavor in ASB and promoted lipid oxidation by altering lipid profiles.

Comparative Analysis of Direct Cold Atmospheric Plasma Treatment vs. Plasma Activated Water for the Deactivation of Omicron Variant of SARS-CoV-2

Comparative Analysis of Direct Cold Atmospheric Plasma Treatment vs. Plasma Activated Water for the Deactivation of Omicron Variant of SARS-CoV-2

Mesoporous silica nanoparticles accommodating electrospun nanofibers as implantable local drug delivery system processed by cold atmospheric plasma and spin coating approaches

Nanofibers (NF) and nanoparticles are attractive for drug delivery to improve the drug bioavailability and administration. Easy manipulation of NF as macroscopic bulk material give rise to potential usages as implantable local drug delivery systems (LLDS) to overcome the failures of systemic drug delivery systems such as unmet personalized needs, side effects, suboptimal dosage. In this study, poly(ethylene glycol) polyethyleneimine (mPEG:PEI) copolymer blended poly ϵ-caprolactone NFs, NFblend accommodating mesoporous silica nanoparticles (MSN) as the implantable LLDS was achieved by employing spin coating and cold atmospheric plasma (CAP) as the post-process for accommodation on NFblend. The macroporous morphology, mechanical properties, wettability, and in vitro cytocompatibility of NFblend ensured their potential as an implantable LLDS and superior features compared to neat NF. The electron microscopy images affirmed of NFblend random fiber (average diameter 832 ± 321 nm) alignments and accessible macropores before and after MSN@Cur accommodation. The blending of polymers improved the elongation of NF and the tensile strength which is attributed as beneficial for implantable LLDS. CAP treatment could significantly improve the wettability of NF observed by the contact angle changes from ∼126° to ∼50° which is critical for the accommodation of curcumin-loaded MSN (MSN@Cur) and in vitro cytocompatibility of NF. The combined CAP and spin coating as the post-processes was employed for accommodating MSN@Cur on NFblend without interfering with the electrospinning process. The post-processing aided fine-tuning of curcumin dosing (∼3 µg to ∼15 µg) per dose unit and sustained zero-order drug release profile could be achieved. Introducing of MSN@Cur to cells via LLDS promoted the cell proliferation compared to MSN@Cur suspension treatments and assigned as the elimination of adverse effects by nanocarriers by the dosage form integration. All in all, NFblend-MSN@Cur was shown to have high potential to be employed as an implantable LLDS. To the best of our knowledge, this is the first study in which mPEG:PEI copolymer blend NF are united with CAP and spin coating for accommodating nano-drug carriers, which allows for NF both tissue engineering and drug delivery applications.

Argon cold atmospheric plasma eradicates pathogens in vitro that are commonly associated with canine bacterial keratitis.

To investigate the antimicrobial effect of cold atmospheric plasma (CAP) on pathogens associated with canine bacterial keratitis. Pseudomonas aeruginosa, Staphylococcus pseudintermedius, and Streptococcus canis strains, which were obtained from dogs with infectious keratitis, were subjected to testing. For each species, four isolates and a reference strain were cultivated on Columbia sheep blood agar and treated with the kiNPen Vet® plasma pen from Neoplas GmbH, Greifswald, Germany. Various continuous treatment durations (0.5, 2, and 5 min) were applied, along with a 0.5-min treatment repeated four times at short intervals. These treatments were conducted at distances of 3 and 18 mm between the agar surface and the pen. CAP treatment reduced bacterial growth in all three species. The most effective treatment duration was 5 min at 3 mm distance, resulting in inhibition zones ranging from 19 to 22 mm for P. aeruginosa, 26-45 mm for S. pseudintermedius and an overall reduction of bacterial growth for Str. canis. Inhibition zones were smaller with decreasing treatment duration and larger distance. Treatment times of 30 s repeated four times and 2 min showed comparable results. Treatment with argon alone did not lead to visible reduction of bacterial growth. Argon cold atmospheric plasma demonstrated a potent in vitro antimicrobial effect on P. aeruginosa, S. pseudintermedius and Str. canis strains with the latter showing the highest sensitivity.

Cold atmospheric plasma modified polycaprolactone solution prior to electrospinning: A novel approach for improving quercetin-loaded nanofiber drug delivery systems

In this study, we present a novel approach for enhancing the performance of Quercetin-loaded nanofiber drug delivery systems through the modification of Polycaprolactone (PCL) solution using Cold Atmospheric Plasma (CAP) prior to electrospinning. CAP treatment was applied to PCL solutions for varying durations, namely, 0.5, 1, and 3 min. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) collectively demonstrate that CAP application and QU loading induce morphological changes in nanofibers, facilitating the creation of drug delivery systems with modified fiber diameters, devoid of bead formation. CAP treatment duration correlates with varying fiber diameters, with the longest treatment (3 min) producing the largest fibers (1324 ± 387 nm). Concurrently, the incorporation of quercetin (QU) into the PCL nanofibers resulted in reduced fiber diameter. These observations emphasize the pivotal role of CAP modification in tailoring nanofiber size and morphology. Notably, minimal peak shifts indicate no significant molecular structure changes in PCL nanofibers compared to PCL solutions, assuring the absence of unwanted chemical modifications or degradation during electrospinning. Furthermore, specific QU peaks are undetectable in Fourier-transform infrared (FTIR) spectra, suggesting dispersed or amorphous QU molecules within the nanofibers. Additionally, X-ray diffraction (XRD) results demonstrate that CAP treatment does not alter the crystalline structure of the PCL nanofiber drug delivery system. Crystalline planes of PCL remain unchanged, affirming stability under CAP treatment conditions. Water contact angles indicate that CAP treatment affects nanofiber hydrophobicity, with shorter CAP treatment times rendering more hydrophilic surfaces. Cumulative QU release percentages vary, with PCL/CAP-0.5-QU exhibiting the highest release at 56 ± 2.2 %, surpassing unmodified PCL/QU. Moreover, cell viability remains comparable or slightly increased when QU is incorporated into CAP-treated PCL nanofibers, suggesting potential mitigation of cytotoxic effects induced by CAP treatment. The combination of QU and CAP treatment enhances cancer cell viability reduction, QU release from nanofibers, and drug loading efficiency in a synergistic manner.

Efficiency of cold atmospheric plasma under ozone (O3) and nitrogen oxide (NOx) regimes on the degradation of aflatoxins and ochratoxin A in solid state and in spiked pistachio kernels

Mycotoxins are the primary contaminants in food that have a significant impact on global food safety and security. Cold atmospheric plasma (CAP) has demonstrated significant potential in reducing mycotoxins among innovative technologies. This study aimed to assess the effectiveness of a surface dielectric barrier discharge (SDBD) CAP system in reducing aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1), G2 (AFG2), and ochratoxin A (OTA). The distinctive feature of the device here used was the ability to operate at two different powers, resulting in two different plasma reactive species ambients: ozone (O3) and nitrogen oxides (NOx) regimes. CAP treatments exhibited a significant reduction of all investigated pure mycotoxins, which was regime, molecule chemical structure, distance from the source and time-dependent. In particular, O3 regime was more effective (AFB1 and AFG1 99%, AFB2 and AFG2 60%, OTA 70% reduction, respectively, at 60 min, 4 cm distance from the plasma source). As low-moisture foods pistachio kernels (Pistacia vera L. seeds) were selected to evaluate the matrix effect. As expected, the mycotoxins were reduced to a much lesser extent than pure molecules. Worthy of note was the 23% reduction of OTA. To our best knowledge, this is the first investigation about OTA degradation in pistachio food matrix by cold plasma. It should also be noted that the pistachios have been artificially contaminated with spots of a mixture of mycotoxins, to best represent a probable real contamination.

Effect of Cold Atmospheric Plasma Treatment on the Bond Strength of Glass Fiber Posts

This study assesses the impact of air dielectric barrier discharge (DBD) cold atmospheric plasma (CAP) on the push-out bond strength of glass fiber posts (GFPs) compared to silane and hydrofluoric (HF) treatments. The surfaces of GFPs were subjected to silane, HF, and CAP treatments, and the effects of these treatments were evaluated using contact angle measurements. Additionally, scanning electron microscopy (SEM) was used to visualize the effects of silane, HF, and CAP treatments on the GFP surfaces. GFPs treated with various surface treatments were then placed in post spaces within root canals, and push-out bond strength was measured at the cervical, middle, and apical regions of the root canal. CAP treatment rendered the surfaces of GFPs superhydrophilic, with a measured contact angle of 0&amp;deg;, while silane and HF-treated surfaces had contact angles of 110.5&amp;deg; and 101.3&amp;deg;, respectively. SEM images revealed that CAP treatment increased the surface roughness of GFPs without damaging the glass fibers, whereas HF treatment caused breakage of exposed glass fibers, and silane covered the GFP surfaces. The push-out bond strength in all regions of the root canal was significantly higher in the CAP-treated group, with an overall bond strength improvement of approximately 3.5-fold compared to the control group. CAP treatment, by inducing superhydrophilicity and enhancing surface roughness without damaging glass fibers, substantially increased the bond strength of GFPs. Consequently, CAP may be considered a state-of-the-art surface treatment technique for enhancing the bond strength of GFPs, offering superior bonding strength of dental posts via superhydrophilicity compared to conventional methods and potentially leading to improved clinical outcomes.

The Effect of Fibroblast Growth Factor and Cold Atmospheric Plasma Treatment on Calcaneus Tendon Healing Activity in Rabbits

The Effect of Fibroblast Growth Factor and Cold Atmospheric Plasma Treatment on Calcaneus Tendon Healing Activity in Rabbits

Non-thermal plasma modulated l-tyrosine self-assemblies: a potential avenue for fabrication of supramolecular self-assembled biomaterials.

Aromatic amino acids (AAs) have garnered particular interest due to their pivotal roles in numerous biological processes and disorders. Variations in AA self-assembly not only affect protein structures and functions, but their non-covalent interactions such as hydrogen bonding, van der Waals forces, and π-π stacking, yield versatile assemblies vital in bio-inspired material fabrication. Tyrosine (Tyr), a non-essential aromatic amino acid, holds multifaceted significance in the body as a protein building block, neurotransmitter precursor, thyroid hormone contributor, and melanin synthesis regulator. The proficiency of Cold Atmospheric Plasma (CAP) in generating a spectrum of reactive oxygen and nitrogen species has spurred innovative research avenues in the studies of biomolecular components, including its potential for targeted cancer cell ablation and biomolecule modification. In this work, we have assessed the chemical as well as the structural changes in Tyrosine-derived self-assembled structures arising from the CAP-induced reactive species. For a comprehensive understanding of the mechanism, different treatment times, feed gases, and the role of solvent acidification are compared using various spectroscopic and microscopic techniques. LC-ESI-QQQ mass spectra unveiled the emergence of oxygenated and nitro derivatives of l-tyrosine following its interaction with CAP-derived ROS/RNS. SEM and TEM images demonstrated an enhanced surface size of self-assembled structures and the formation of novel nanomaterial-shaped assemblies following CAP treatment. Overall, this study aims to explore CAP's interaction with a single-amino acid, hypothesizing the creation of novel supramolecular structures and scrutinizing CAP-instigated transformations in l-tyrosine self-assembled structures, potentially advancing biomimetic-attributed nanomaterial fabrication which might present a novel frontier in the field of designing functional biomaterials.

Inactivation Kinetics of Pathogenic and Nonpathogenic Bacteria Upon In Vitro Treatment With Cold Atmospheric Pressure Plasma (CAPP).

In the present study, selected pathogenic (Salmonella Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus) and nonpathogenic (Pseudomonas fragi, Pseudomonas fluorescens, Brochothrix thermosphacta, Bacillus subtilis, Lactiplantibacillus plantarum, and Leuconostoc mesenteroides) bacteria were subjected in vitro in cold atmospheric pressure plasma (CAPP) treatment for up to 15 min and the changes in the surviving microbial population were determined. Plasma treatments were carried out by a plasma jet device, operating with argon (Ar) as carrier gas under constant flow (4.0 L/min) at a frequency of 1 MHz and an electrical voltage of 2-6 kV. Microbial inactivation data were modelled using linear and nonlinear (Geeraerd, Weibull) models, through which the corresponding kinetic parameters were calculated. After 15 min of exposure to plasma radiation, the total reduction in the bacterial populations was 2.12 log10 CFU mL-1 for P. fragi, 1.77 log10 CFU mL-1 for P. fluorescens, 2.30 log10 CFU mL-1 for B. thermosphacta, 1.58 log10 CFU mL-1 for B. subtilis, 1.31 log10 CFU mL-1 for L. plantarum, 3.80 log10 CFU mL-1 for L. mesenteroides (highest reduction observed), 1.12 log10 CFU mL-1 for S. Typhimurium, 1.18 log10 CFU mL-1 for E. coli, 1.43 log10 CFU mL-1 for L. monocytogenes, 1.32 log10 CFU mL-1 for B. cereus, 0.88 log10 CFU mL-1 for S. aureus, and 0.73 log10 CFU mL-1 for P. aeruginosa. The results showed a higher reduction in the population of nonpathogenic microorganisms compared to pathogens. The relatively small decrease in the inactivation of bacteria indicates that parameter optimization is necessary to be considered to improve the efficacy of the treatment.

Atmospheric Cold Plasma Treatment of Whey: Insights Into Microbiological Quality and Structural Characteristics of Whey Proteins

Atmospheric Cold Plasma Treatment of Whey: Insights Into Microbiological Quality and Structural Characteristics of Whey Proteins