In vivo study on the repair of rat Achilles tendon injury treated with non-thermal atmospheric-pressure helium microplasma jet.

Non-thermal atmospheric-pressure plasma (NTAPP) has been widely studied for clinical applications, e.g., disinfection, wound healing, cancer therapy, hemostasis, and bone regeneration. It is being revealed that the physical and chemical actions of plasma have enabled these clinical applications. Based on our previous report regarding plasma-stimulated bone regeneration, this study focused on Achilles tendon repair by NTAPP. This is the first study to reveal that exposure to NTAPP can accelerate Achilles tendon repair using a well-established Achilles tendon injury rat model. Histological evaluation using the Stoll's and histological scores showed a significant improvement at 2 and 4 weeks, with type I collagen content being substantial at the early time point of 2 weeks post-surgery. Notably, the replacement of type III collagen with type I collagen occurred more frequently in the plasma-treated groups at the early stage of repair. Tensile strength test results showed that the maximum breaking strength in the plasma-treated group at two weeks was significantly higher than that in the untreated group. Overall, our results indicate that a single event of NTAPP treatment during the surgery can contribute to an early recovery of an injured tendon.

Overcoming antibiotic resistance: non-thermal plasma and antibiotics combination inhibits important pathogens.

Antibiotic resistance (ATBR) is increasing every year as the overuse of antibiotics (ATBs) and the lack of newly emerging antimicrobial agents lead to an efficient pathogen escape from ATBs action. This trend is alarming and the World Health Organization warned in 2021 that ATBR could become the leading cause of death worldwide by 2050. The development of novel ATBs is not fast enough considering the situation, and alternative strategies are therefore urgently required. One such alternative may be the use of non-thermal plasma (NTP), a well-established antimicrobial agent actively used in a growing number of medical fields. Despite its efficiency, NTP alone is not always sufficient to completely eliminate pathogens. However, NTP combined with ATBs is more potent and evidence has been emerging over the last few years proving this is a robust and highly effective strategy to fight resistant pathogens. This minireview summarizes experimental research addressing the potential of the NTP-ATBs combination, particularly for inhibiting planktonic and biofilm growth and treating infections in mouse models caused by methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa. The published studies highlight this combination as a promising solution to emerging ATBR, and further research is therefore highly desirable.

Antimicrobial efficacy of direct air gas soft jet plasma for the in vitro reduction of oral bacterial biofilms.

The aim of this study was to evaluate the antimicrobial efficacy of an air gas soft jet CAP for its potential use in removing oral biofilms, given that plasma-based technologies have emerged as promising methods in periodontology. Two types of biofilms were developed, one by Streptococcus mutans UA 159 bacterial strain and the other by a complex mixture of saliva microorganisms isolated from a patient with periodontitis. This latter biofilm was characterized via Next Generation Sequencing to determine the main bacterial phyla. The CAP source was applied at a distance of 6 mm for different time points. A statistically significant reduction of both CFU count and XTT was already detected after 60 s of CAP treatment. CLSM analysis supported CAP effectiveness in killing the microorganisms inside the biofilm and in reducing the thickness of the biofilm matrix. Cytotoxicity tests demonstrated the possible use of CAP without important side effects towards human gingival fibroblasts cell line. The current study showed that CAP treatment was able to significantly reduce preformed biofilms developed by both S. mutans and microorganisms isolated by a saliva sample. Further studies should be conducted on biofilms developed by additional saliva donors to support the potential of this innovative strategy to counteract oral pathogens responsible for periodontal diseases.

Human coronavirus 229E inactivation on porous and nonporous materials using dielectric barrier discharge (DBD) plasma.

Viruses can spread through contaminated aerosols and contaminated surface materials, and effective disinfection techniques are essential for virus inactivation. Nonthermal plasma-generated reactive oxygen and nitrogen species can effectively inactivate the coronavirus. We aim to interpret the coronavirus inactivation level and mechanism of surface interaction with materials with and without dielectric barrier discharge (DBD) plasma treatment. Nonthermal plasma, particularly surface-type DBD plasma, can inactivate human coronavirus 229E (HCoV-229E) on porous (paper, wood, mask) and nonporous (plastic, stainless steel, glass, Cu) materials. Virus inactivation was analyzed using a 50% tissue culture infectivity dose (TCID50) using cell line, flow cytometry, and immunofluorescence. Surfaces contaminated with HCoV-229E were treated at different time intervals (0-5 h) with and without plasma exposure (natural decay in ambient air conditions). HCoV-229E persistence conformed to the following order: plastic > cover glass > stainless steel > mask > wood > paper > Cu with and without plasma exposure. HCoV-229E was more stable in plastic, cover glass, and stainless steel in 5 h, and the viable virus titer gradually decreased from its initial log10 order of 6.892 to 1.72, 1.53, and 1.32 TCID50/mL, respectively, under plasma exposure. No virus was observed in Cu after treatment for 5 h. The use of airflow, ambient nitrogen, and argon did not promote virus inactivation. Flow cytometry and immunofluorescence analysis demonstrated a low expression level of spike protein (fluorescence intensity) during plasma treatment and in E and M genes expression compared with the virus control.

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.

Novel Nonthermal Atmospheric Plasma Irradiation of Titanium Implants Promotes Osteogenic Effect in Osteoporotic Conditions.

Osteoporosis is a metabolic disease characterized by bone density and trabecular bone loss. Bone loss may affect dental implant osseointegration in patients with osteoporosis. To promote implant osseointegration in osteoporotic patients, we further used a nonthermal atmospheric plasma (NTAP) treatment device previously developed by our research group. After the titanium implant (Ti) is placed into the device, the working gas flow and the electrode switches are turned on, and the treatment is completed in 30 s. Previous studies showed that this NTAP device can remove carbon contamination from the implant surface, increase the hydroxyl groups, and improve its wettability to promote osseointegration in normal conditions. In this study, we demonstrated the tremendous osteogenic enhancement effect of NTAP-Ti in osteoporotic conditions in rats for the first time. Compared to Ti, the proliferative potential of osteoporotic bone marrow mesenchymal stem cells on NTAP-Ti increased by 180% at 1 day (P = 0.004), while their osteogenic differentiation increased by 149% at 14 days (P < 0.001). In addition, the results indicated that NTAP-Ti significantly improved osseointegration in osteoporotic rats in vivo. Compared to the Ti, the bone volume fraction (BV/TV) and trabecular number (Tb.N) values of NTAP-Ti in osteoporotic rats, respectively, increased by 18% (P < 0.001) and 25% (P = 0.007) at 6 weeks and the trabecular separation (Tb.Sp) value decreased by 26% (P = 0.02) at 6 weeks. In conclusion, this study proved a novel NTAP irradiation titanium implant that can significantly promote osseointegration in osteoporotic conditions.

Inactivation of microorganisms on fabrics using plasma-activated nebulized mist driven by different plasma gases.

The disinfection of fabrics is crucial in preventing the spread of infectious diseases caused by pathogenic microorganisms to maintain public health. A previous study proved that plasma-activated nebulized mist (PANM) could effectively inactivate microorganisms both in aerosol and attached to the surface. In this study, the PANM driven by different plasma gases were employed to inactivate microorganisms on diverse fabrics. The PANM could efficiently inactivate a variety of microorganisms, including bacteria, fungi, and viruses, contaminating different fabrics, and even across covering layers of different fabrics. The mites residing on the cotton fabrics both uncovered and covered with various types of fabrics were also effectively inactivated by the PANM. After 30 times repeated treatments of the PANM, notable changes were observed in the color of several fabrics while the structural integrity and mechanical strength of the fabrics were unaffected and maintained similarly to the untreated fabrics with slight changes in elemental composition. Additionally, only trace amounts of nitrate remained in the fabrics after the PANM treatment. Therefore, the PANM treatment supplied an efficient, broad-spectrum, and environmentally friendly strategy for industrial and household disinfection of fabrics.

The synergistic effect of dielectric barrier discharge plasma and phycocyanin on shelf life of Oncorhynchus mykiss rainbow fillets.

This study aimed to evaluate the efficacy of dielectric barrier discharge treatment (DBD) combined with phycocyanin pigment (PC) in extending the shelf life of Oncorhynchus mykiss rainbow fillets stored at 4 ± 0.1 °C. Microbiological, physicochemical, sensory and antioxidant properties were assessed over an 18-day storage period. The combined DBD and PC treatment significantly inhibited total viable counts and Psychrotrophic bacteria counts compared to the rest of the samples throughout storage. While Total Volatile Nitrogen concentrations remained below international standard until day 18, they exceeded this threshold in control sample by day 9. DBD treatment notably reduced Trimethylamine levels compared to controls (p < 0.05). PC and DBD combined inhibited DPPH and ABTS radical scavenging capacities by 80% and 85%, respectively, while demonstrating heightened iron-reducing antioxidant activity compared to controls. Analysis of 24 fatty acids indicated that PC mitigated DBD's adverse effects, yielding superior outcomes compared to controls. The ratio of n-3 to n-6 fatty acids in all samples met or fell below international standard. Thus, the combined use of DBD and PC shows promise in extending fillet shelf life by over 15 days at 4 °C.

Fracture healing on non-union fracture model promoted by non-thermal atmospheric-pressure plasma.

Non-thermal atmospheric-pressure plasma (NTAPP) is attracting widespread interest for use in medical applications. The tissue repair capacity of NTAPP has been reported in various fields; however, little is known about its effect on fracture healing. Non-union or delayed union after a fracture is a clinical challenge. In this study, we aimed to investigate how NTAPP irradiation promotes fracture healing in a non-union fracture model and its underlying mechanism, in vitro and in vivo. For the in vivo study, we created normal and non-union fracture models in LEW/SsNSlc rats to investigate the effects of NTAPP. To create a fracture, a transverse osteotomy was performed in the middle of the femoral shaft. To induce the non-union fracture model, the periosteum surrounding the fracture site was cauterized after a normal fracture model was created. The normal fracture model showed no significant difference in bone healing between the control and NTAPP-treated groups. The non-union fracture model demonstrated that the NTAPP-treated group showed consistent improvement in fracture healing. Histological and biomechanical assessments confirmed the fracture healing. The in vitro study using pre-osteoblastic MC3T3-E1 cells demonstrated that NTAPP irradiation under specific conditions did not reduce cell proliferation but did enhance osteoblastic differentiation. Overall, these results suggest that NTAPP is a novel approach to the treatment of bone fractures.

Fungicidal efficiency of DBD cold plasma against Aspergillus niger on dried jujube.

This study investigated the fungicidal efficiency and mechanism of action of dielectric barrier discharge cold atmosphere plasma (DBD-CAP) in inactivating Aspergillus niger (A. niger) spores. The disinfection efficacy and quality of dried jujube used as the processing application object were also studied. The results indicated that the Weibull + Tail model performed better for spore inactivation curves at different voltages among various treatment times, and the spore cells were reduced by 4.05 log (cfu/mL) in spores suspension at 70 kV after 15 min of treatment. This disinfection impact was further supported by scanning electron microscope (SEM) and transmission electron microscopy (TEM) images, which showed that the integrity of the cell membrane was damaged, and the intracellular content leaked out after DBD-CAP treatment. Elevated levels of reactive oxygen species (ROS) during the treatment increased the relative conductivity of cells, and leakage of nucleic acids and proteins further supported the disinfection impact. Additionally, the growth and toxicity of surviving A. niger spores after treatment were also greatly reduced. When DBD-CAP was applied to disinfecting dried jujube, the spore number exhibited a 2.67 log cfu/g reduction after treatment without significant damage observed onto the quality (P > 0.05).

Cold atmospheric plasma attenuates skin cancer via ROS induced apoptosis.

BACKGROUND: Cold atmospheric plasma (CAP) has been widely used in biomedical research, especially in vitro cancer therapy. Cutaneous squamous cell carcinoma (CSCC) is a malignant tumor originating from epidermal keratinocytes. However, the mechanism of CAP therapy on CSCC remains unclear. METHODS AND RESULTS: The animal models of CSCC induced by 7,12-dimethylbenz(a) anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) were constructed. For the CAP treatment group, after each TPA application, CAP was administered for 3 min twice weekly after drying. HE staining were used to detect the pathological status of tumor tissue in each group. The levels of PCNA, Bcl-2, Bax, MMP2 and MMP9 were evaluated by western blot and qPCR. TUNEL staining were used to detect apoptosis in tumor tissues. In vivo, serum samples were used for ELISA of total ROS. MTT assay was used to detect the viability of A431 cells. Western blot and qPCR were used to detect the levels of PCNA, Bcl-2, Bax, MMP2 and MMP9 in A431 cells. A431 cell proliferation was examined by colony formation assay. The proportions of apoptosis of A431 cells were detected by flow cytometry. Transwell assessed the ability of A431 cells migration and proliferation. We found that CAP could induce skin cancer cells apoptosis and inhibit the progress of skin cancer. Through experiments in vitro, reactive oxygen species (ROS) generated by N-acetylcysteine (NAC) and CAP inhibited the proliferation and migration of A431 skin cancer cells while promoting apoptosis. CONCLUSIONS: These evidences suggest the protective effect of CAP in CSCC, and CAP has the potential clinical application of CSCC.

Wound healing capacity of using mesenchymal stem cell-derived exosomes originated from human adipose tissue and cold atmospheric plasma.

Background: Recently, cold atmospheric plasma (CAP), as well as adipose mesenchymal stem cells derived exosomes (ADMSCs-EX), have been applied separately to wound healing treatment. However, no study has investigated the additive effect on the healing mechanism of these two methods in the same skin lesion treatment model. Aim: We conduct this study to describe the results of using CAP and human ADMSCs-EX on in vitro wound healing. Methods: Exosomes were isolated from donor adipose tissue samples by ultracentrifugation method, characterized by transmission electron microscopy (TEM) and Western blot. Assessment in vitro wound healing on proliferation and migration evaluation experiments on human fibroblasts with culture medium supplemented with 10µg total exosomal proteins/1 mL and irradiated with CAP with an intensity of 30 seconds/cm2. Results: Experimental results to evaluate the ability to stimulate fibroblast migration, showed that cell migration speed in the group supplemented with ADMSCs-EX was equivalent to the group with a combination of CAP and ADMSCs-EX and had the highest rate with 87.8 ± 4.2 % and 84.4 ± 5.3 % while in the control group it was the lowest with 61.9 ± 11.4% (p<0.05). The group supplemented with CAP gave fibroblast proliferation and migration results similar to the control group (p>0.05), showing the safety of CAP with the growth of the cells. Conclusions: Therefore, in animal models, we intend to use a combination of these two therapies by using ADMSCs-EX injection therapy into the dermis at the wound edge to avoid the impact of CAP affecting the cell proliferation.

How does atmospheric pressure cold helium plasma affect the biomechanical behaviour on alkali-lesioned corneas?

BACKGROUND: Melting corneal ulcers are a serious condition that affects a great number of animals and people around the world and it is characterised by a progressive weakening of the tissue leading to possible severe ophthalmic complications, such as visual impairment or blindness. This disease is routinely treated with medical therapy and keratoplasty, and recently also with alternative regenerative therapies, such as cross-linking, amniotic membrane transplant, and laser. Plasma medicine is another recent example of regenerative treatment that showed promising results in reducing the microbial load of corneal tissue together with maintaining its cellular vitality. Since the effect of helium plasma application on corneal mechanical viscoelasticity has not yet been investigated, the aim of this study is first to evaluate it on ex vivo porcine corneas for different exposition times and then to compare the results with previous data on cross-linking treatment. RESULTS: 94 ex vivo porcine corneas divided into 16 populations (healthy or injured, fresh or cultured and treated or not with plasma or cross-linking) were analysed. For each population, a biomechanical analysis was performed by uniaxial stress-relaxation tests, and a statistical analysis was carried out considering the characteristic mechanical parameters. In terms of equilibrium normalised stress, no statistically significant difference resulted when the healthy corneas were compared with lesioned plasma-treated ones, independently of treatment time, contrary to what was obtained about the cross-linking treated corneas which exhibited more intense relaxation phenomena. CONCLUSIONS: In this study, the influence of the Helium plasma treatment was observed on the viscoelasticity of porcine corneas ex vivo, by restoring in lesioned tissue a degree of relaxation similar to the one of the native tissue, even after only 2 min of application. Therefore, the obtained results suggest that plasma treatment is a promising new regenerative ophthalmic therapy for melting corneal ulcers, laying the groundwork for further studies to correlate the mechanical findings with corneal histology and ultrastructural anatomy after plasma treatment.

Elimination of Chlorella using peracetic acid activated by dielectric barrier discharge plasma: Mechanism and cell deactivation process.

Excessive proliferation of algae in water depletes dissolved oxygen, resulting in the demise of aquatic life and environmental damage. This study delves into the effectiveness of the dielectric barrier discharge (DBD) plasma activated peracetic acid (PAA) system in deactivating Chlorella. Within 15 min, the algae removal effectiveness reached 89 % under ideal trial conditions. DBD plasma activation of PAA augmented the concentration of reactive species such as ·OH, 1O2, and organic radicals (RO·) in the solution, which are involved in the process of cell inactivation. Reactive oxygen species (ROS) within Chlorella cells continued to rise as a result of treatment-induced damage to the morphological structure and cell membrane of the organism. DNA and chlorophyll-a (Chl-a), were oxidized and destroyed by these invasive active compounds. This study presents an efficient advanced oxidation method to destroy algal cells and adds an alternative strategy for algal control in areas where eutrophication occurs.

Effect of (multi pin) atmospheric cold plasma treatment on curcumin extraction and investigating phytochemicals, antioxidants, physical and morphological properties of turmeric (Curcuma longa L.) powder.

This investigation was focused on the impact of cold plasma (CP) on the extraction of curcumin and bioactive compounds of turmeric powder (TP). TP was treated with CP at different applied voltages (10, 20, and 30 kV), with various exposure times (10, 20, and 30 min). The curcumin content was highest at 30 kV for 10 min with a yield of 46.49 mg/g of TP. Total phenols significantly (p < 0.05) enhanced from 163.91 to 360.78 mg GAE/g DW accompanied by a remarkable 16% increment in total flavonoids, paralleled by a 26% increment in antioxidants as of control. Nuclear magnetic resonance spectra justified the extraction of curcuminoids. Moreover, micrographs displayed cell lysis in the treated powder. CP has exhibited a positive effect on surface colour parameters and thermal properties of TP. Overall, CP technology can be tailored for better curcumin extraction and the enhancement of phytochemicals.

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

BACKGROUND: High 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. METHODS: The 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. RESULTS: Decitabine 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. CONCLUSIONS: CAP combined with decitabine induced Caspase-3 activation, which cleaved decitabine-upregulated GSDME and ediated pyroptosis.

In-package cold plasma treatment to extend the shelf life of food.

Conventional food preservation methods such as heat treatment, irradiation, chemical treatment, refrigeration, and coating have various disadvantages, like loss of food quality, nutrition, and cost-effectiveness. Accordingly, cold plasma is one of the new technologies for food processing and has played an important role in preventing food spoilage. Specifically, in-package cold plasma has become a modern trend to decontaminate, process, and package food simultaneously. This strategy has proven successful in processing various fresh food ingredients, including spinach, fruits, vegetables, and meat. In particular, cold plasma treatment within the package reduces the risk of post-processing contamination. Cryoplasm decontamination within packaging has been reported to reduce significantly the microbial load of many foods' spoilage-causing pathogens. However, studies are needed to focus more on the effects of in-package treatments on endogenous enzyme activity, pest control, and removal of toxic pesticide residues. In this review, we comprehensively evaluated the efficacy of in-package low-temperature plasma treatment to extend the shelf life of various foods. The mechanisms by which cold plasma interacts with food were investigated, emphasizing its effects on pathogen reduction, spoilage mitigation, and surface modification. The review also critically assessed the effects of the treatments on food quality, regulatory considerations, and their potential as viable technologies to improve food safety and packaging life. In-package cold plasma treatment could revolutionize food storage when combined with other sophisticated technologies such as nanotechnology.

Nonthermal plasma air disinfection for the inactivation of airborne microorganisms in an experimental chamber and indoor air.

AIMS: Airborne transmission of diseases presents a serious threat to human health, so effective air disinfection technology to eliminate microorganisms in indoor air is very important. This study evaluated the effectiveness of a non-thermal plasma (NTP) air disinfector in both laboratory experiments and real environments. METHODS AND RESULTS: An experimental chamber was artificially polluted with a bioaerosol containing bacteria or viruses. Additionally, classroom environments with and without people present were used in field tests. Airborne microbial and particle concentrations were quantified. A 3.0 log10 reduction in the initial load was achieved when a virus-containing aerosol was disinfected for 60 min and a bacteria-containing aerosol was disinfected for 90 min. In the field test, when no people were present in the room, NTP disinfection decreased the airborne microbial and particle concentrations (P < 0.05). When people were present in the room, their constant activity continuously contaminated the indoor air, but all airborne indicators decreased (P < 0.05) except for planktonic bacteria (P = 0.094). CONCLUSIONS: NTP effectively inactivated microorganisms and particles in indoor air.

Electromagnetic Nature of Distant Interaction of the Atmospheric Pressure Helium Plasma Discharge Tube with Glioblastoma Cancer Cells.

Atmospheric pressure coaxial gaseous discharge tubes (DTs) with helium have demonstrated potential for in vitro inactivation or sensitization of glioblastoma cancer cells. Here, we study the effect of two configurations of the DT electrode system on its electromagnetic emissivity as well as other physical factors (heating and UV emission) that form in the vicinity of this device. We demonstrate that the configuration of the DT electrodes that concentrates the discharge streamers near the top of the device has a distant (cm scale) deactivation effect on U87-MG glioblastoma cancer cells when irradiated, without measurable UV components in the DT optical emission spectra. This effect persists even through different barriers such as glass, plastic, or quartz Petri dishes but is eliminated when glass or plastic dishes are filled with water. These findings demonstrate the potential for development of noninvasive, physical-based treatment methods of deep-tissue tumors.

Application of Argon Plasma Technology for the Synthesis of Anti-Infective Copper Nanoparticles.

The synthesis of copper nanoparticles (CuNPs) was accomplished by using a rapid, green, and versatile argon plasma reduction method that involves solvent extraction. With this method, a plasma-solid state interaction forms and CuNPs can be synthesized from copper(II) sulfate using a low-pressure, low-temperature argon plasma. Characterization studies of the CuNPs revealed that when a metal precursor is treated under optimal experimental conditions of 80 W of argon plasma for 300 s, brown CuNPs are synthesized. However, when those same brown CuNPs are placed in Milli-Q water for a period of 10 days, oxidation occurs and green CuNPs are formed. Confirmation of the chemical identity of the CuNPs was performed by using X-ray photoelectron spectroscopy. The results reveal that the brown CuNPs are predominantly Cu0 or what we refer to as CuNPs, while the green CuNPs are a mixture of Cu0 and Cu(OH)2 NPs. Upon further characterization of both brown and green CuNPs with scanning electron microscopy (SEM), the results depict brown CuNPs with a rod-like shape and approximate dimensions of 40 nm × 160 nm, while the green CuNPs were smaller in size, with dimensions of 40-80 nm, and more of a round shape. When testing the antibacterial activity of both brown and green CuNPs, our findings demonstrate the effectiveness of both CuNPs against Escherichia coli and Staphylococcus aureus bacteria at a concentration of 17 µg/mL. The inactivation of S. aureus and E. coli 7-day-old biofilms required CuNP concentrations of 99 µg/mL. SEM images of treated 7-day-old S. aureus and E. coli biofilms depict cell membranes that are completely damaged, suggesting a physical killing mechanism. In addition, when the same concentration of CuNPs used to inactivate biofilms were tested with human fibroblasts, both brown and green CuNPs were found to be biocompatible.