In vivo study of non-invasive effects of non-thermal plasma in pressure ulcer treatment

Analysis of inflammation and bone remodeling of atmospheric plasma therapy in experimental periodontitis

BACKGROUND AND OBJECTIVE

The biological effects of atmospheric plasma (cold plasma) show its applicability for controlling the etiological factors that involve tissue repair. Thus, the study evaluated the effect of atmospheric plasma therapy in the control of tissue inflammation and bone remodeling in experimental periodontitis.

METHODS

Fifty-six rats were subjected to ligation in the cervical region of the first maxillary molars (8 weeks). The animals were divided into two groups (n = 28): periodontitis without treatment group (P group), and periodontitis with atmospheric plasma treatment group (P + AP group). Tissue samples were collected at 2 and 4 weeks after treatment to analyze the inflammation and bone remodeling by biochemical, histomorphometric, and immunohistochemical analyses.

RESULTS

Inflammatory infiltration in the gingival and periodontal ligament was lower in the P + AP group than in the P group (p < .05). The MPO and NAG levels were higher in the P + AP group compared to P group (p < .05). At 4 weeks, the TNF-α level was lower and the IL-10 level was higher in the P + AP group compared to P group (p < .05). In the P + AP group, the IL-1β level increased in the second week and decreased in the fourth week (p < .05), the number of blood vessels was high in the gingival and periodontal ligament in the second and fourth week (p < .05); and the number of fibroblasts in the gingival tissue was low in the fourth week, and higher in the periodontal tissue in both period (p < .05). Regarding bone remodeling, the RANK and RANKL levels decreased in the P + AP group (p < .05). The OPG level did not differ between the P and P + AP groups (p > .05), but decreased from the second to the fourth experimental week in P + AP group (p < .05).

CONCLUSIONS

The treatment of experimental periodontitis with atmospheric plasma for 4 weeks modulated the inflammatory response to favor the repair process and decreased the bone resorption biomarkers, indicating a better control of bone remodeling in periodontal disease.

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.

Enhanced Fat Graft Viability and Remodeling Using a Helium-based Radiofrequency Device to Prepare the Recipient Site

BACKGROUND

Improvements to autologous fat grafting for soft tissue augmentation are needed to overcome the unpredictable volume retention. Approaches such as fat harvesting and processing, injection technique, preparation of the recipient site, and supplemental biologics are topics of ongoing research. Here, an energy-based device was investigated as a stimulatory tool for recipient site preparation for improving fat graft retention.

OBJECTIVE

The objective was to measure the stimulatory responses in fat grafts after 4 weeks when using a helium-based radiofrequency device to pretreat the recipient tissue.

METHODS

Using an autologous fat grafting mouse model, the inguinal fat pad was grafted in a small cranial pocket after either a saline injection alone (control) or a saline injection followed by pretreatment (treated). The fat pad was resected after 4 weeks, sectioned and stained with immunofluorescence markers to investigate tissue remodeling.

RESULTS

Pretreatment resulted in higher viability of adipocytes, a higher concentration of viable ASCs in areas of adipose tissue regeneration, and localized macrophages in the areas of regeneration when compared to the control. There was no observable difference in vascularity or angiogenesis. The staining for ASCs was higher in the pretreated group in comparison with the control group (5.0% vs. 3.3%, p=0.36) when using a pixel classifier in QuPath in the viable adipose tissue regions.

CONCLUSIONS

The use of a helium-based radiofrequency device as a pretreatment tool appears to increase the viability of the adipose tissue likely due to higher concentration of ASCs. The apparent increase in viable ASCs may be due to enhanced proliferation or paracrine recruitment of these cells in response to the helium-based radiofrequency treatment.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 . Bullet List of Important Points: Pretreatment of the fat graft recipient site increases the viability of the adipose tissue after 4 weeks in comparison with the control grafts. The increased viability is likely due to the observed increase in adipose-derived stem cells in the pretreated group. Pretreatment enhanced the adipose tissue remodeling as colocalization of adipose-derived stem cells and macrophages showed an active remodeling, whereas the control group exhibited more necrotic and fibrotic tissue.

Harnessing Non-Thermal Plasma to Supercharge Recovery in Abdominal Surgeries: A Pilot Study

(1) Background: This study aims to evaluate the efficacy and safety of non-thermal plasma (NTP) therapy in accelerating wound healing in patients who have undergone laparoscopic and open surgeries. (2) Methods: NTP was applied using a needle-type reactor with an irradiance of 0.5 W/cm2 on the surgical wounds of fifty patients after obtaining informed consent. Three NTP treatments, each lasting three minutes, were administered hourly. (3) Results: The pilot study showed that NTP-treated surgical wounds healed completely without any signs of infection, dehiscence, pain, or itching. Notably, patients reported minimal pain after the NTP treatment. Visual assessments conducted twenty-four hours after surgery revealed no redness or fluid discharge. Comparisons with traditionally sutured wounds indicated that NTP-treated wounds healed at a rate equivalent to seven days. (4) Conclusions: The application of NTP in laparoscopic and open wounds proved safe and effective, expediting the wound healing process and eliminating clinical risks post-surgery. Significantly, NTP facilitated a healing rate within twenty-four hours, equivalent to seven days for suture-treated wounds, significantly reducing the hospitalization time to a single day. These findings highlight the potential of NTP to be a transformative approach for promoting postoperative recovery.

Innovative cold atmospheric plasma (iCAP) decreases corneal ulcer formation and bacterial loads and improves anterior chamber health in methicillin resistant Staphylococcus aureus keratitis

Bacterial keratitis is a vision-threatening infection of the cornea that is typically treated with antibiotics. However, antibiotics sometimes fail to eradicate the infection and do not prevent or repair the damage caused directly by the bacteria or the host immune response to the infection. Our group previously demonstrated that treatment of Pseudomonas aeruginosa keratitis in rabbits with innovative cold atmospheric plasma (iCAP) resulted in reduced edema, ulcer formation, and bacterial load. In this study, we investigated the efficacy of iCAP treatment in methicillin-resistant Staphylococcus aureus (MRSA). New Zealand white rabbits were infected intrastromally with MRSA then treated with iCAP, moxifloxacin, vancomycin, or combination of iCAP with each antibiotic to assess the safety and efficacy of iCAP treatment compared to untreated controls and antibiotics. iCAP treatment significantly reduced bacterial loads and inflammation, improved anterior chamber clarity, and prevented corneal ulceration compared to untreated controls and antibiotic treatment. Safety assessments of grimace test scores and tear production showed that iCAP was not significantly different from either antibiotic treatment in terms of distress or tear production. Combination iCAP/antibiotic treatment did not appear to provide significant added benefit over iCAP alone. Our findings suggest that the addition of iCAP may be a viable tool in reducing damage to the cornea and anterior chamber of the eye following S. aureus keratitis.

Reactive species variation in cold atmospheric pressure plasma jet discharge under the influence of intrinsic parameters and its effect on E. coli inactivation

Cold atmospheric pressure plasma jet (CAPJ) has piqued the interest of researchers for various antimicrobial applications such as disinfection, wound decontamination, etc. In the current context, a deeper understanding of the correlation between CAPJ's intrinsic parameters, discharge characteristics, species composition, and antimicrobial activity is required for any successful application. This research evaluated the effect of intrinsic operational parameters such as voltage, frequency, gas flow rate, and operating gas on the reactive species composition of an in-house-developed CAPJ discharge along with the antimicrobial activity. It was observed that the identified excited atoms (Ar I, He I, N2, and O I), ions (Ar+, N2+, N+, H2O+, H3O+, etc.), radical reactive oxygen and nitrogen species (RONS) (OH•), and nonradical RONS (O I, O+, OH+, NO+, O2+, O2-, NO2-, N2O2-, NO3-, N2O3-, etc.) might play a synergistic role in bacterial inactivation via oxidative and electrostatic stress. The variation in voltage, frequency, gas flow rate, and operating gas influenced the discharge chemistry, leading to variation in bacterial inactivation. The reactive species in the discharge responsible for such variation was evaluated extensively. This investigation into various operational parameters would aid in determining the most effective settings for a developed CAPJ to achieve high productivity.

Capacitively Coupled Plasma from Laser-Induced Graphene Points to Ozone as the Major Mediator of Antibacterial Activity

Low-temperature plasma is an emerging approach for the treatment of bacterial infections. Nonchemical treatments such as cold plasma offer potential solutions to antibiotic resistance. We investigated the use of laser-induced graphene as an inexpensive, lightweight, and portable electrode for generating cold plasma. At the same time, the mechanism or molecular mediators of cold plasma-induced antibacterial activity remain poorly understood. This study validates graphene as an efficient structure for producing therapeutic cold plasma, and this study also indicates that ozone is the primary mediator of antibacterial activity in graphene-mediated cold plasmas for bacterial growth under the conditions studied.

Non-Thermal Plasma Application in Medicine-Focus on Reactive Species Involvement

Non-thermal plasma (NTP) application in medicine is a dynamically developing interdisciplinary field. Despite the fact that basics of the plasma phenomenon have been known since the 19th century, growing scientific attention has been paid in recent years to the use of plasma in medicine. Three most important plasma-based effects are pivotal for medical applications: (i) inactivation of a broad spectrum of microorganisms, (ii) stimulation of cell proliferation and angiogenesis with lower plasma treatment intensity, and (iii) inactivation of cells by initialization of cell death with higher plasma intensity. In this review, we explain the underlying chemical processes and reactive species involvement during NTP in human (or animal) tissues, as well as in bacteria inactivation, which leads to sterilization and indirectly supports wound healing. In addition, plasma-mediated modifications of medical surfaces, such as surgical instruments or implants, are described. This review focuses on the existing knowledge on NTP-based in vitro and in vivo studies and highlights potential opportunities for the development of novel therapeutic methods. A full understanding of the NTP mechanisms of action is urgently needed for the further development of modern plasma-based medicine.

Comparing the efficacy of plasma exeresis and cryotherapy for the treatment of seborrheic keratosis: A randomized controlled trial

BACKGROUND

Seborrheic keratoses (SK) is a benign epithelial skin tumor and plasma exeresis is a new technique.

AIMS

To compare the efficacy and safety of plasma exeresis and cryotherapy for treating SK.

METHODS

This study is a randomized controlled trial (RCT). One side of each patient was randomly treated with plasma exeresis (peak-to-peak voltage of 3.44 kV and a frequency of 62.5 kHz) and the other side with cryotherapy.

RESULTS

Thirty-five males were enrolled. At week 3, 37.1 % (N = 13) of lesions treated by plasma exeresis were clear, which was higher than those treated by cryotherapy 17.1% (N = 6). However, this difference was not significant (p-value: 0.06). At week 6, 16 (57.1 %) out of 28 remaining lesions, treated by plasma exeresis were clear, which was significantly higher (p-value: 0.005) than those completely cleared by cryotherapy in 6 out of 29 remaining lesions (20.7%). The mean physician assessment scale score was significantly reduced in both groups in the second follow-up (plasma group first follow-up 0.91 ± 0.89 vs. second follow-up 0.5 ± 0.64 and p-value: 0.0031; cryo group first follow-up 1.4 ± 0.84 vs. second follow-up 1.1 ± 0.72 and p-value: 0.0002). Regarding side effects, no significant difference was seen (p = 0.438). The most common complications in the plasma and cryotherapy groups were erythema (10/19, 52.63%) and hypo pigmentation (5/13, 38.46%).

CONCLUSIONS

Both cryotherapy and plasma exeresis are effective. We observed a significantly higher cleared lesions treated with plasma exeresis in 6 weeks and after two sessions.

Applications of atmospheric cold plasma in agricultural, medical, and bioprocessing industries

Abstract

Atmospheric cold plasma (ACP) is a nonthermal technology that is extensively used in several industries. Within the scopes of engineering and biotechnology, some notable applications of ACP include waste management, material modification, medicine, and agriculture. Notwithstanding numerous applications, ACP still encounters a number of challenges such as diverse types of plasma generators and sizes, causing standardization challenges. This review focuses on the uses of ACP in engineering and biotechnology sectors in which the innovation can positively impact the operation process, enhance safety, and reduce cost. Additionally, its limitations are examined. Since ACP is still in its nascent stage, the review will also propose potential research opportunities that can help scientists gain more insights on the technology.

Key points

• ACP technology has been used in agriculture, medical, and bioprocessing industries.

• Chemical study on the reactive species is crucial to produce function-specific ACP.

• Different ACP devices and conditions still pose standardization problems.

Wound healing in db/db mice with type 2 diabetes using non-contact exposure with an argon non-thermal atmospheric pressure plasma jet device

A non-thermal atmospheric pressure plasma jet (APPJ) may stimulate cells and tissues or result in cell death depending on the intensity of plasma at the target; therefore, we herein investigated the effects of non-thermal plasma under non-contact conditions on the healing of full-thickness wounds in diabetic mice (DM+ group) and normal mice (DM- group). A hydrogen peroxide colorimetric method and high performance liquid chromatography showed that APPJ produced low amounts of reactive oxygen and nitrogen species. Ten-week-old male C57BL/6j mice with normal blood glucose levels (DM- group) and 10-week-old male C57BLKS/J Iar-+Leprdb/+Leprdb mice (DM+ group) received two full-thickness cutaneous wounds (4 mm in diameter) on both sides of the dorsum. Wounds were treated with or without the plasma jet or argon gas for 1 minute and were then covered with a hydrocolloid dressing (Hydrocolloid), according to which mice were divided into the following groups: DM+Plasma, DM+Argon, DM+Hydrocolloid, DM-Plasma, DM-Argon, and DM-Hydrocolloid. Exudate weights, wound areas, and wound area ratios were recorded every day. Hematoxylin and eosin staining was performed to assess re-epithelialization and α-SMA immunohistological staining to evaluate the formation of new blood vessels. Non-thermal plasma under non-contact conditions reduced the production of exudate. Exudate weights were smaller in the DM+Plasma group than in the DM+Hydrocolloid and DM+Argon groups. The wound area ratio was smaller for plasma-treated wounds, and was also smaller in the DM+Plasma group than in the DM+Hydrocolloid and DM+Argon groups on days 1-21 (p<0.01). Wound areas were smaller in the DM-Plasma group than in the DM-Argon group until day 14 and differences were significant on days 1-5 (p<0.01). The percentage of re-epithelialization was significantly higher in the DM+Plasma group than in the DM+Argon and DM+Hydrocolloid groups (p<0.01). The number of new blood vessels that had formed by day 7 was significantly higher in the DM+Plasma group than in the DM+Hydrocolloid and DM+Argon groups (p<0.05). These results indicate that treatment with the current non-thermal plasma APPJ device under non-contact conditions accelerated wound healing in diabetic mice.

Plasma Dermatology: Skin Therapy Using Cold Atmospheric Plasma

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

Non-Invasive Physical Plasma Treatment after Tooth Extraction in a Patient on Antiresorptive Medication Promotes Tissue Regeneration

Postoperative tissue regeneration can be negatively affected by bisphosphonate administration, especially in patients with oncologic diseases. A serious complication of bisphosphonate therapy is the medication-related osteonecrosis of the jaw (MRONJ), which can be observed mainly after dental surgery. MRONJ is a progressive destruction of the bone that requires patients to stay in hospital for extended periods of time. For this reason, primary wound closure is particularly important in surgical procedures. In the case of wound dehiscence, there is a very high risk for MRONJ. In recent years, non-invasive physical plasma (NIPP) has become known for improving wound healing on the one hand, but also for its promising efficacy in cancer therapy on the other hand. We report on a 63-year-old patient with a history of multiple myeloma and receiving zoledronate, who developed wound dehiscence after tooth extraction. NIPP treatment resulted in complete epithelialization of the entire wound dehiscence. In conclusion, the use of NIPP in patients receiving antiresorptive drugs seems to support tissue regeneration and thus could be an important tool for the prevention of MRONJ.

Antibacterial and anticandidal effects of atmospheric-pressure, non-thermal, nitrogen- and argon-plasma pulses

Atmospheric-pressure, non-thermal plasma destroys microorganisms by directly reacting with hydrocarbon molecules in the cell wall and/or by damaging the cytoplasmic membrane, proteins, and DNA with charged particles and reactive species. The aim of our study was to evaluate the antibacterial and anticandidal effects of atmospheric-pressure, non-thermal, nitrogen- and argon-plasma pulses on various pathogen preparations. The resultant antibacterial and anticandidal effects were assessed by evaluating percent and log reduction values for pathogen colonies. Nitrogen-plasma pulses emitted at an energy of 1.5 J and argon-plasma pulses generated at 0.5 J elicited remarkable antibacterial effects on Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA) and anticandidal effects on Candida albicans. Nitrogen-plasma pulses at a pulse count of five elicited remarkable antibacterial effects on Cutibacterium acnes at the energy settings of 1.75, 2.5, and 3 J, but not at 1 J. Meanwhile, argon-plasma pulses showed antibacterial effects on C. acnes at an energy of 0.5 and 0.65 J. Nitrogen- or argon-plasma pulses exert antibacterial and anticandidal effects on bacterial and fungal pathogens.

Alternative Approaches for the Management of Diabetic Foot Ulcers

Diabetic foot ulcers (DFU) represent a growing public health problem. The emergence of multidrug-resistant (MDR) bacteria is a complication due to the difficulties in distinguishing between infection and colonization in DFU. Another problem lies in biofilm formation on the skin surface of DFU. Biofilm is an important pathophysiology step in DFU and may contribute to healing delays. Both MDR bacteria and biofilm producing microorganism create hostile conditions to antibiotic action that lead to chronicity of the wound, followed by infection and, in the worst scenario, lower limb amputation. In this context, alternative approaches to antibiotics for the management of DFU would be very welcome. In this review, we discuss current knowledge on biofilm in DFU and we focus on some new alternative solutions for the management of these wounds, such as antibiofilm approaches that could prevent the establishment of microbial biofilms and wound chronicity. These innovative therapeutic strategies could replace or complement the classical strategy for the management of DFU to improve the healing process.

Medical gas plasma-stimulated wound healing: Evidence and mechanisms

Defective wound healing poses a significant burden on patients and healthcare systems. In recent years, a novel reactive oxygen and nitrogen species (ROS/RNS) based therapy has received considerable attention among dermatologists for targeting chronic wounds. The multifaceted ROS/RNS are generated using gas plasma technology, a partially ionized gas operated at body temperature. This review integrates preclinical and clinical evidence into a set of working hypotheses mainly based on redox processes aiding in elucidating the mechanisms of action and optimizing gas plasmas for therapeutic purposes. These hypotheses include increased wound tissue oxygenation and vascularization, amplified apoptosis of senescent cells, redox signaling, and augmented microbial inactivation. Instead of a dominant role of a single effector, it is proposed that all mechanisms act in concert in gas plasma-stimulated healing, rationalizing the use of this technology in therapy-resistant wounds. Finally, addressable current challenges and future concepts are outlined, which may further promote the clinical utilization, efficacy, and safety of gas plasma technology in wound care in the future.

Evaluation of cold atmospheric-pressure plasma against burn wound infections and gene silencing

Background and Objectives

Non-thermal atmospheric-pressure plasma or cold plasma is defined as an ionized gas. This study aimed to investigate the effect of cold plasma on Pseudomonas aeruginosa strains. Also, the expression level of the alp virulence gene before and after treatment with cold plasma was compared with the Housekeeping gene gyrA.

Materials and Methods

P. aeruginosa isolates recovered from hospitalized burn patients at Shahid Motahari Burns Hospital, Tehran, Iran. The Kirby Bauer disk diffusion method was used to determine the antimicrobial susceptibility test. Then, the antibacterial effect of atmospheric non-thermal plasma was evaluated on P. aeruginosa in as in vitro and in vivo studies at different times on Muller Hinton agar and in mouse model (treated by plasma every day/ 90 sec). The histopathological study was evaluated by Hematoxylin-Eosin staining. Data were analyzed using SPSS software by the Chi-square test and Pvalues less than 0.05 considered as statistically significant.

Results

Results indicated that non-thermal atmospheric plasma inhibited the growth of P. aeruginosa. The non-thermal helium plasma accelerates wound healing for 6 days. Results showed that cold plasma decreased virulence gene expression alp after treatment. Therefore, cold plasma can be suggested as a complementary therapeutic protocol to reduce bacterial infection and accelerate wound healing and reduce the expression of virulence genes of pathogens.

Conclusion

Cold plasma showed pathogen inhibitory properties of P. aeruginosa and virulence alkaline protease and wound healing properties in animal models, so this inexpensive and suitable method can be presented to the medical community to disinfect burn wounds and improve wound healing.

Gas Plasma-Augmented Wound Healing in Animal Models and Veterinary Medicine

The loss of skin integrity is inevitable in life. Wound healing is a necessary sequence of events to reconstitute the body’s integrity against potentially harmful environmental agents and restore homeostasis. Attempts to improve cutaneous wound healing are therefore as old as humanity itself. Furthermore, nowadays, targeting defective wound healing is of utmost importance in an aging society with underlying diseases such as diabetes and vascular insufficiencies being on the rise. Because chronic wounds’ etiology and specific traits differ, there is widespread polypragmasia in targeting non-healing conditions. Reactive oxygen and nitrogen species (ROS/RNS) are an overarching theme accompanying wound healing and its biological stages. ROS are signaling agents generated by phagocytes to inactivate pathogens. Although ROS/RNS’s central role in the biology of wound healing has long been appreciated, it was only until the recent decade that these agents were explicitly used to target defective wound healing using gas plasma technology. Gas plasma is a physical state of matter and is a partially ionized gas operated at body temperature which generates a plethora of ROS/RNS simultaneously in a spatiotemporally controlled manner. Animal models of wound healing have been vital in driving the development of these wound healing-promoting technologies, and this review summarizes the current knowledge and identifies open ends derived from in vivo wound models under gas plasma therapy. While gas plasma-assisted wound healing in humans has become well established in Europe, veterinary medicine is an emerging field with great potential to improve the lives of suffering animals.

Influences of cold atmospheric plasma on apoptosis related molecules in osteoblast-like cells in vitro

Background

Cold atmospheric plasma (CAP) has recently been identified as a novel therapeutic strategy for supporting processes of wound healing. Since CAP is additionally known to kill malignant cells, our study intends to determine the influence of CAP on crucial molecules involved in the molecular mechanism of apoptosis in osteoblast-like cells.

Methods

Human osteoblast-like cells were CAP-treated for 30 and 60 s. CAP effects on critical factors related to apoptosis were studied at transcriptional and protein level using real time-PCR, immunofluorescence staining and western blot. Phalloidin / DAPI staining was used for analyzing the cell morphology. In addition, apoptotic outcomes of CAP were displayed using flow cytometry analysis. For studying intracellular signaling pathways, MAP kinase MEK 1/2 and PI3K were blocked. Finally, the effects of CAP on caspase-3 activity were examined using a caspase-3 assay.

Results

CAP treatment resulted in a significant downregulation of p53 and apoptotic protease activating factor (APAF)-1, caspase (CASP)9, CASP3, BCL2 Antagonist/Killer (BAK)1, and B-Cell Lymphoma (BCL)2 mRNA expression at 1 d. An inhibitory effect of CAP on apoptotic genes was also shown under inflammatory and apoptotic conditions. Nuclear translocation of p53 was determined in CAP treated cells at the early and late stage, after 15 min, 30 min, and 1 h. p53 and APAF-1 protein levels were reduced at 1 d, visualized by immunofluorescence and western blot, respectively. Moreover, a morphological cytoskeleton modification was observed after CAP treatment at 1 d. Further, both CAP-treated and untreated (control) cells remained equally vital as detected by flow cytometry analysis. Interestingly, CAP-associated downregulation of CASP9 and CASP3 mRNA gene expression was also visible after blocking MAP kinase and PI3K. Finally, CAP led to a decrease in CASP3 activity in osteoblast-like cells under normal and apoptotic conditions.

Conclusions

Our in vitro-study demonstrated, that CAP decreases apoptosis related molecules in osteoblast-like cells, underlining a beneficial effect on hard-tissue cells.

Inhibitory Effect of Cold Atmospheric Plasma on Chronic Wound-Related Multispecies Biofilms

The presence of microbial biofilms in the wounds affects negatively the healing process and can contribute to therapeutic failures. This study aimed to establish the effective parameters of cold atmospheric plasma (CAP) against wound-related multispecies and monospecies biofilms, and to evaluate the cytotoxicity and genotoxicity of the protocol. Monospecies and multispecies biofilms were formed by methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Enterococcus faecalis. The monospecies biofilms were grown in 96 wells plates and multispecies biofilm were formed on collagen membranes. The biofilms were exposed to helium CAP for 1, 3, 5 and 7 min. In monospecies biofilms, the inhibitory effect was detected after 1 min of exposure for E. faecalis and after 3 min for MRSA. A reduction in P. aeruginosa biofilm’s viability was detected after 7 min of exposure. For the multispecies biofilms, the reduction in the overall viability was detected after 5 min of exposure to CAP. Additionally, cytotoxicity and genotoxicity were evaluated by MTT assay and static cytometry, respectively. CAP showed low cytotoxicity and no genotoxicity to mouse fibroblastic cell line (3T3). It could be concluded that He-CAP showed inhibitory effect on wound-related multispecies biofilms, with low cytotoxicity and genotoxicity to mammalian cells. These findings point out the potential application of CAP in wound care.

Plasma bioscience and its application to medicine

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

Acidified Nitrite Contributes to the Antitumor Effect of Cold Atmospheric Plasma on Melanoma Cells

Cold atmospheric plasma (CAP) is partially ionized gas near room temperature with previously reported antitumor effects. Despite extensive research and growing interest in this technology, active components and molecular mechanisms of CAP are not fully understood to date. We used Raman spectroscopy and colorimetric assays to determine elevated nitrite and nitrate levels after treatment with a MiniFlatPlaster CAP device. Previously, we demonstrated CAP-induced acidification. Cellular effects of nitrite and strong extracellular acidification were assessed using live-cell imaging of intracellular Ca²⁺ levels, cell viability analysis as well as quantification of p21 and DNA damage. We further characterized these observations by analyzing established molecular effects of CAP treatment. A synergistic effect of nitrite and acidification was found, leading to strong cytotoxicity in melanoma cells. Interestingly, protein nitration and membrane damage were absent after treatment with acidified nitrite, thereby challenging their contribution to CAP-induced cytotoxicity. Further, phosphorylation of ERK1/2 was increased after treatment with both acidified nitrite and indirect CAP. This study characterizes the impact of acidified nitrite on melanoma cells and supports the importance of RNS during CAP treatment. Further, it defines and evaluates important molecular mechanisms that are involved in the cancer cell response to CAP.

Cold atmospheric plasma applications in dermatology: A systematic review

Cold atmospheric plasma (CAP) applications can potentially lead to effective therapy for numerous skin diseases. Our aim is to systematically review the available data and map the use of CAP in dermatology. PubMed, Embase and Web of science were explored before 2020 for studies regarding the use of CAP in dermatology. A total of 166 studies were finally included. 74.1% of these studies used indirect CAP sources. Most studies used plasma jet (67.5%). Argon was the mostly used working gas (48.2%). Plasma application itself could be direct (89.2%) and indirect (16.3%). The proportion of studies with in vivo results remained 57.2%, of which most concerned direct plasma treatment (97.9%). Analyses performed indicate that CAP has been beneficial in many skin disorders. While, most CAP applications were focused on wound healing and melanoma treatment. This study provides a brief overview of CAP sources and relative medical applications in dermatology.

Antibacterial and safety tests of a flexible cold atmospheric plasma device for the stimulation of wound healing

Cold atmospheric plasma (CAP) devices generate an ionized gas with highly reactive species and electric fields at ambient air pressure and temperature. A flexible dielectric barrier discharge (DBD) was developed as an alternative antimicrobial treatment for chronic wounds. Treatment of Staphylococcus aureus in collagen-elastin matrices with CAP for 2 min resulted in a 4 log reduction. CAP treatment was less effective on S. aureus on dermal samples. CAP did not affect cellular activity or DNA integrity of human dermal samples when used for up to 2 min. Repeated daily CAP treatments for 2 min lowered cellular activity of dermal samples to 80% after 2 to 4 days, but this was not significant. Repeated treatment of ex vivo human burn wound models with CAP for 2 min did not affect re-epithelialization. Intact skin of 25 healthy volunteers was treated with CAP for 3× 20" to determine safety. Although participants reported moderate pain scores (numerical rating scale 3.3), all volunteers considered the procedure to be acceptable. Severe adverse events did not occur. CAP treatment resulted in a temporarily increased local skin temperature (≈3.4°C) and increased erythema. Lowering the plasma power resulted in a significantly lower erythema increase. Good log reduction (2.9) of bacterial load was reached in 14/15 volunteers artificially contaminated with Pseudomonas aeruginosa. This study demonstrated the in vitro and in vivo safety and efficacy in bacterial reduction of a flexible cold plasma device. Trial registration number NCT03007264, January 2, 2017 KEY POINTS: • CAP strongly reduced bacterial numbers both in vitro and in vivo. • Re-epithelialization of burn wound models was not affected by repeated CAP. • CAP treatment of intact skin was well tolerated in volunteers.

Could cold plasma act synergistically with allogeneic mesenchymal stem cells to improve wound skin regeneration in a large size animal model?

Skin wound healing may sometimes lead to open sores that persist for long periods and expensive hospitalization is needed. Among different kinds of therapeutic innovative approaches, mesenchymal stem cells (MSCs) and low-temperature atmospheric pressure cold plasma (ionized gas) have been recently tested to improve this regenerative process. To optimize wound healing the present study intended to combine, for the first time, these two novel approaches in a large size animal wound healing model with the aim of assessing the putative dual beneficial effects. Based on clinical, histopathological, and molecular results a synergistic action in a second intention healing wound in sheep has been observed. Experimental wounds treated with cold plasma and MSCs showed a slower but more effective healing compared to the single treatment, as observed in previous studies. The combined treatment improved the correct development of skin appendages and structural proteins of the dermis showing the potential of the dual combination as a safe and effective tool for skin regeneration in the veterinary clinical field.

The antimicrobial and tissue healing efficacy of the atmospheric pressure cold plasma on grade III infected pressure ulcer: randomized controlled in vivo experiment

AIM

To evaluate the antimicrobial efficacy and wound healing effect of atmospheric pressure cold plasma (APCP) on an infected pressure ulcer (IPUs) model that was created on rats.

METHODS

A total of 18 rats was divided into APCP, silver sulfadiazine (AgS) and control groups to have six rats in each group. A third-grade pressure ulcer model was developed on the back of each of the rats, and pressure ulcers were infected by inoculation of multidrug resistance (MDR) Pseudomonas aeruginosa. A portable dielectric barrier discharge device was used to generate cold air plasma. APCP, AgS and saline treatments were carried out once a day for 14 days. The effectiveness of the treatment was evaluated on days 5, 10 and 15. Surface area, depth, pressure ulcer healing scale (PUSH) and microbiological examination were used for evaluation.

RESULTS

The results of this study showed that APCP was superior over AgS application and irrigation with saline by means of the reduction in surface area and depth of ulcers. Furthermore, PUSH score in plasma group was lower than other groups and histopathological examination showed a higher epithelization in APCP group. The average reductions of MDR P. aeruginosa for APCP, AgS and control groups were determined as 5·64 ± 1·87, 1·91 ± 0·90 and 1·22 ± 0·88 log10 CFU per gram tissue, respectively.

CONCLUSION

Atmospheric pressure cold plasma healed IPUs better than AgS.

SIGNIFICANCE AND IMPACT OF THE STUDY

Portable cold plasma devices could be a potential novel treatment modality for the patients who have IPUs.

The molecular and physiological consequences of cold plasma treatment in murine skin and its barrier function

Cold plasma technology is an emerging tool facilitating the spatially controlled delivery of a multitude of reactive species (ROS) to the skin. While the therapeutic efficacy of plasma treatment has been observed in several types of diseases, the fundamental consequences of plasma-derived ROS on skin physiology remain unknown. We aimed to bridge this gap since the epidermal skin barrier and perfusion plays a vital role in health and disease by maintaining homeostasis and protecting from environmental damage. The intact skin of SKH1 mice was plasma-treated in vivo. Gene and protein expression was analyzed utilizing transcriptomics, qPCR, and Western blot. Immunofluorescence aided the analysis of percutaneous skin penetration of curcumin. Tissue oxygenation, perfusion, hemoglobin, and water index was investigated using hyperspectral imaging. Reversed-phase liquid-chromatography/mass spectrometry was performed for the identification of changes in the lipid composition and oxidation. Transcriptomic analysis of plasma-treated skin revealed modulation of genes involved in regulating the junctional network (tight, adherence, and gap junctions), which was confirmed using qPCR, Western blot, and immunofluorescence imaging. Plasma treatment increased the disaggregation of cells in the stratum corneum (SC) concomitant with increased tissue oxygenation, gap junctional intercellular communication, and penetration of the model drug curcumin into the SC preceded by altered oxidation of skin lipids and their composition in vivo. In summary, plasma-derived ROS modify the junctional network, which promoted tissue oxygenation, oxidation of SC-lipids, and restricted penetration of the model drug curcumin, implicating that plasma may provide a novel and sensitive tool of skin barrier regulation.

Physical plasma therapy accelerates wound re-epithelialisation and enhances extracellular matrix formation in cutaneous skin grafts

Skin grafting is a surgical method of cutaneous reconstruction, which provides volumetric replacement in wounds unable to heal by primary intention. Clinically, full-thickness skin grafts (FTSGs) are placed in aesthetically sensitive and mechanically demanding areas such as the hands, face, and neck. Complete or partial graft failure is the primary complication associated with this surgical procedure. Strategies aimed at improving the rate of skin graft integration will reduce the incidence of graft failure. Cold atmospheric plasma (CAP) is an emerging technology offering innovative clinical applications. The aim of this study was to test the therapeutic potential of CAP to improve wound healing and skin graft integration into the recipient site. In vitro models that mimic wound healing were used to investigate the ability of CAP to enhance cellular migration, a key factor in cutaneous tissue repair. We demonstrated that CAP enhanced the migration of epidermal keratinocytes and dermal fibroblasts. This increased cellular migration was possibly induced by the low dose of reactive oxygen and nitrogen species produced by CAP. Using a mouse model of burn wound reconstructed with a full-thickness skin graft, we showed that wounds treated with CAP healed faster than did control wounds. Immunohistochemical wound analysis showed that CAP treatment enhanced the expression of the dermal-epidermal junction components, which are vital for successful skin graft integration. CAP treatment was characterised by increased levels of Tgfbr1 mRNA and collagen I protein in vivo, suggesting enhanced wound maturity and extracellular matrix deposition. Mechanistically, we show that CAP induced the activation of the canonical SMAD-dependent TGF-β1 pathway in primary human dermal fibroblasts, which may explain the increased collagen I synthesis in vitro. These studies revealed that CAP improved wound repair and skin graft integration via mechanisms involving extracellular matrix formation. CAP offers a novel approach for treating cutaneous wounds and skin grafts. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

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

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

Helium/Argon-Generated Cold Atmospheric Plasma Facilitates Cutaneous Wound Healing

Cold atmospheric plasma jet (CAPJ) or non-thermal plasma jet has been employed in various biomedical applications based on their functions in bactericidal activity and wound healing. However, the effect of CAPJ generated by a particular composition of gases on wound closure and the underlying mechanisms that regulate wound healing signals remain elusive. In the present study, we investigated the impact of helium (He)- or a gas mixture of He and argon (He/Ar)-generated CAPJ on cell proliferation, which is a pivotal step during the wound healing process. With careful treatment duration control, He/Ar-CAPJ effectively induced keratinocyte proliferation and migration mediated through the activation of epithelial-to-mesenchymal transition (EMT) and cell cycle progression, which was evidenced by a decrease in E-cadherin levels and increases in N-cadherin, cyclin D1, Ki-67, Cdk2, and p-ERK levels. Rat wound healing studies showed that He/Ar-CAPJ treatment facilitated granulation tissue formation and mitigated inflammation in cutaneous tissue, resulting in accelerated wound closure. These findings highlight the possibility that He/Ar-CAPJ can be developed as a therapeutic agent for enhancing wound healing.

Cold Atmospheric Plasma: A Powerful Tool for Modern Medicine

Cold atmospheric plasma use in clinical studies is mainly limited to the treatment of chronic wounds, but its application in a wide range of medical fields is now the goal of many analyses. It is therefore likely that its application spectrum will be expanded in the future. Cold atmospheric plasma has been shown to reduce microbial load without any known significant negative effects on healthy tissues, and this should enhance its possible application to any microbial infection site. It has also been shown to have anti-tumour effects. In addition, it acts proliferatively on stem cells and other cultivated cells, and the highly increased nitric oxide levels have a very important effect on this proliferation. Cold atmospheric plasma use may also have a beneficial effect on immunotherapy in cancer patients. Finally, it is possible that the use of plasma devices will not remain limited to surface structures, because current endeavours to develop sufficiently miniature microplasma devices could very likely lead to its application in subcutaneous and internal structures. This study summarises the available literature on cold plasma action mechanisms and analyses of its current in vivo and in vitro use, primarily in the fields of regenerative and dental medicine and oncology.

Potential effect of non-thermal plasma for the inhibition of scar formation: a preliminary report

Non-thermal plasma (NTP) is a promising biomedical tool for application to wound healing. However, there is limited scientific evidence that confirms its efficacy to inhibit scar formation. This study aims to investigate the role of non-thermal plasma in scar formation. Two full-thickness dorsal cutaneous wounds of rats were treated with either a non-thermal helium plasma jet or helium. It was determined that the non-thermal plasma jet accelerated the wound healing process from 5 days after surgery (day 5: 41.27% ± 2.351 vs 54.7% ± 5.314, p < 0.05; day 7: 56.05% ± 1.881 vs 75.28% ± 3.914, p < 0.01; day 14: 89.85% ± 2.991 vs 98.07% ± 0.839, p < 0.05). The width of the scars for the NTP group was narrower than those of control group (4.607 ± 0.416 mm vs 3.260 ± 0.333 mm, p < 0.05). In addition, a lower level of TGF-β1, p-Smad2 and p-Smad3 were detected in the NTP treated wounds (p < 0.05, p < 0.01 and p < 0.01). As expected, α-SMA was also significantly decreased in the NTP treatment group (p < 0.01). Moreover, the expression of type I collagen and the proportion of type I to III collagen were lower in the NTP group (p < 0.05). The results of the study suggest that NTP may play a potential role in scar formation by inhibiting the TGF β1 signal pathway and reducing the levels of α-SMA and type I collagen, and may have clinical utility in the future.

Plasma Medicine: A Field of Applied Redox Biology

Plasma medicine comprises the application of physical plasma directly on or in the human body for therapeutic purposes. Three most important basic plasma effects are relevant for medical applications: i) inactivation of a broad spectrum of microorganisms, including multidrug-resistant pathogens, ii) stimulation of cell proliferation and angiogenesis with lower plasma treatment intensity, and iii) inactivation of cells by initialization of cell death with higher plasma treatment intensity, above all in cancer cells. Based on own published results as well as on monitoring of relevant literature the aim of this topical review is to summarize the state of the art in plasma medicine and connect it to redox biology. One of the most important results of basic research in plasma medicine is the insight that biological plasma effects are mainly mediated via reactive oxygen and nitrogen species influencing cellular redox-regulated processes. Plasma medicine can be considered a field of applied redox biology.

Modifying the Tumour Microenvironment: Challenges and Future Perspectives for Anticancer Plasma Treatments

Tumours are complex systems formed by cellular (malignant, immune, and endothelial cells, fibroblasts) and acellular components (extracellular matrix (ECM) constituents and secreted factors). A close interplay between these factors, collectively called the tumour microenvironment, is required to respond appropriately to external cues and to determine the treatment outcome. Cold plasma (here referred as ‘plasma’) is an emerging anticancer technology that generates a unique cocktail of reactive oxygen and nitrogen species to eliminate cancerous cells via multiple mechanisms of action. While plasma is currently regarded as a local therapy, it can also modulate the mechanisms of cell-to-cell and cell-to-ECM communication, which could facilitate the propagation of its effect in tissue and distant sites. However, it is still largely unknown how the physical interactions occurring between cells and/or the ECM in the tumour microenvironment affect the plasma therapy outcome. In this review, we discuss the effect of plasma on cell-to-cell and cell-to-ECM communication in the context of the tumour microenvironment and suggest new avenues of research to advance our knowledge in the field. Furthermore, we revise the relevant state-of-the-art in three-dimensional in vitro models that could be used to analyse cell-to-cell and cell-to-ECM communication and further strengthen our understanding of the effect of plasma in solid tumours.

Effects of argon and nitrogen plasma pulses on the skin and skin appendages in an in vivo animal model

BACKGROUND

For medical purposes, plasma can be generated from inert gaseous sources in a device by ultra-high-frequency generators and emitted to target tissue at a pulse duration in the milliseconds.

OBJECTIVE

To evaluate argon and nitrogen plasma pulse-induced tissue reactions in the skin and skin appendages of an in vivo animal model.

METHODS

Argon and nitrogen plasma pulses were non-invasively delivered to in vivo rat skin at various experimental settings. Specimens were histologically evaluated following hematoxylin and eosin and Masson's trichrome staining.

RESULTS

At low-energy settings of 1.0, 1.5, and 2.0 J, nitrogen plasma treatments generated noticeable tissue coagulation at the depths of 31.5 ± 8.3, 94.9 ± 16.9, and 171.6 ± 19.7 µm, respectively, at Day 0. At high-energy settings of 2.5 and 3.0 J, nitrogen plasma treatments generated marked tissue coagulation at the depths of 381.7 ± 33.6 µm and 456.3 ± 75.7 µm, respectively, at Day 0.

CONCLUSIONS

Treatment with argon plasma induces microscopic changes in the epidermis, dermis, and sebaceous glands without generating excessive thermal injury, whereas that with nitrogen plasma elicits energy-dependent thermal coagulation in the epidermis and dermis with remarkable neocollagenesis.

Wound Healing Potential of Low Temperature Plasma in Human Primary Epidermal Keratinocytes

BACKGROUND

Low temperature plasma (LTP) was recently shown to be potentially useful for biomedical applications such as bleeding cessation, cancer treatment, and wound healing, among others. Keratinocytes are a major cell type that migrates directionally into the wound bed, and their proliferation leads to complete wound closure during the cutaneous repair/regeneration process. However, the beneficial effects of LTP on human keratinocytes have not been well studied. Therefore, we investigated migration, growth factor production, and cytokine secretion in primary human keratinocytes after LTP treatment.

METHODS

Primary cultured keratinocytes were obtained from human skin biopsies. Cell viability was measured with the EZ-Cytox cell viability assay, cell migration was evaluated by an in vitro wound healing assay, gene expression was analyzed by quantitative real-time polymerase chain reaction, and protein expression was measured by enzyme-linked immunosorbent assays and western blotting after LTP treatment.

RESULTS

Cell migration, the secretion of several cytokines, and gene and protein levels of angiogenic growth factors increased in LTP-treated human keratinocytes without associated cell toxicity. LTP treatment also significantly induced the expression of hypoxia inducible factor-1α (HIF-1α), an upstream regulator of angiogenesis. Further, the inhibition of HIF-1α expression blocked the production of angiogenic growth factors induced by LTP in human keratinocytes.

CONCLUSION

Our results suggest that LTP treatment is an effective approach to modulate wound healing-related molecules in epidermal keratinocytes and might promote angiogenesis, leading to improved wound healing.

Physical plasma and leukocytes - immune or reactive?

Leukocytes are professionals in recognizing and removing pathogenic or unwanted material. They are present in virtually all tissues, and highly motile to enter or leave specific sites throughout the body. Less than a decade ago, physical plasmas entered the field of medicine to deliver their delicate mix of reactive species and other physical agents for mainly dermatological or oncological therapy. Plasma treatment thus affects leukocytes via direct or indirect means: immune cells are either present in tissues during treatment, or infiltrate or exfiltrate plasma-treated areas. The immune system is crucial for human health and resolution of many types of diseases. It is therefore vital to study the response of leukocytes after plasma treatment in vitro and in vivo. This review gathers together the major themes in the plasma treatment of innate and adaptive immune cells, and puts these into the context of wound healing and oncology, the two major topics in plasma medicine.

Evaluation of an Electro-Pneumatic Device for Artificial Capillary Pulse Generation used in a Prospective Study in Animals for Surgical Neck Wound Healing

The paper examines the development and testing of an electro-pneumatic device for wound healing therapy after surgery in the neck area. The device generates air pressure values in a miniaturized cuff using electronic circuitry to drive an electro-valve and air compressor. The device works in two distinct modes: continuous pressure mode and pulsating pressure mode. The pressure value setting can vary from 3 to 11 mmHg, and the pulsating pressure mode’s operating frequency range is approximately 0.1 to 0.3 Hz. Laboratory measurements were conducted to evaluate the device’s correct functioning in both continuous and pulsating pressure modes. A four-day prospective study with animals (n = 10) was also conducted to evaluate neck wound healing therapy using the electro-pneumatic device. Out of the twelve histological parameters analysed to reveal the differences between the experimental and control wounds, only one demonstrated a significant difference. Out of the ten animals treated with the device, three showed a significant difference in terms of benefit after therapy. We can therefore conclude that the device potentially improves the wound healing process in the neck area if the pre-set air pressure value does not exceed 8 mmHg.

Cold atmospheric plasma promotes different types of superficial skin erosion wounds healing

Superficial skin erosion wounds are very common in the clinic, and conventional treatments are not always effective; thus, effective and novel therapy is needed. Cold atmospheric plasma (CAP) has been recognised as a promising approach to wound healing. The purpose of this study is to show the potential clinical application of CAP for the healing of different kinds of superficial skin wounds. Seven patients with different kinds of superficial skin wounds (two patients with pyoderma gangrenosum, two patients with trauma would, one patient with giant genital wart, one patient with diabetic foot, and one patient with chronic eczema) were recruited to this study. All patients accepted and received CAP treatment every other day till the wound healed. The expected results were complete wound healing after CAP treatment. All patients achieved complete wound healing after several rounds (range from two to eight) of CAP treatment, and there was no side effect observed. CAP may provide a new and effective choice to solve the problem of the healing of superficial wounds that are not only caused by trauma but also because of eczema. CAP has certain value in the treatment of superficial skin diseases in the future.

Short exposure to cold atmospheric plasma induces senescence in human skin fibroblasts and adipose mesenchymal stromal cells

Cold Atmospheric Plasma (CAP) is a novel promising tool developed in several biomedical applications such as cutaneous wound healing or skin cancer. Nevertheless, in vitro studies are lacking regarding to CAP effects on cellular actors involved in healthy skin healing and regarding to the mechanism of action. In this study, we investigated the effect of a 3 minutes exposure to CAP-Helium on human dermal fibroblasts and Adipose-derived Stromal Cells (ASC) obtained from the same tissue sample. We observed that CAP treatment did not induce cell death but lead to proliferation arrest with an increase in p53/p21 and DNA damages. Interestingly we showed that CAP treated dermal fibroblasts and ASC developed a senescence phenotype with p16 expression, characteristic morphological changes, Senescence-Associated β-galactosidase expression and the secretion of pro-inflammatory cytokines defined as the Senescence-Associated Secretory Phenotype (SASP). Moreover this senescence phenotype is associated with a glycolytic switch and an increase in mitochondria content. Despite this senescence phenotype, cells kept in vitro functional properties like differentiation potential and immunomodulatory effects. To conclude, we demonstrated that two main skin cellular actors are resistant to cell death but develop a senescence phenotype while maintaining some functional characteristics after 3 minutes of CAP-Helium treatment in vitro.

Acidification is an Essential Process of Cold Atmospheric Plasma and Promotes the Anti-Cancer Effect on Malignant Melanoma Cells

(1) Background: Cold atmospheric plasma (CAP) is ionized gas near room temperature. The anti-cancer effects of CAP were confirmed for several cancer types and were attributed to CAP-induced reactive species. However, the mode of action of CAP is still not well understood. (2) Methods: Changes in cytoplasmic Ca²⁺ level after CAP treatment of malignant melanoma cells were analyzed via the intracellular Ca²⁺ indicator fura-2 AM. CAP-produced reactive species were determined by fluorescence spectroscopic and protein nitration by Western Blot analysis. (3) Results: CAP caused a strong acidification of water and solutions that were buffered with the so-called Good buffers, while phosphate-buffered solutions with higher buffer capacity showed minor pH reductions. The CAP-induced Ca²⁺ influx in melanoma cells was stronger in acidic pH than in physiological conditions. NO formation that is induced by CAP was dose- and pH-dependent and CAP-treated solutions only caused protein nitration in cells under acidic conditions. (4) Conclusions: We describe the impact of CAP-induced acidification on the anti-cancer effects of CAP. A synergistic effect of CAP-induced ROS, RNS, and acidic conditions affected the intracellular Ca²⁺ level of melanoma cells. As the microenvironment of tumors is often acidic, further acidification might be one reason for the specific anti-cancer effects of CAP.

Prevention of Peritoneal Adhesions by Non-Thermal Dielectric Barrier Discharge Plasma Treatment on Mouse Model: A Proof of Concept Study

Purposes: Formation of peritoneal adhesions is a common consequence of abdominopelvic surgeries and remarkably increases the mortality and morbidity. Moreover, peritoneal adhesions linked to chronic abdominopelvic pain and infertility in women. Various attempts for prevention of peritoneal adhesions were reported. However, these methods either remain insufficient to prevent formation of peritoneal adhesions or carry some practical limitations and thus, there is a need for novel techniques that could effectively decrease the formation of peritoneal adhesions. The aim of the present prospective, randomized, controlled, and single blinded study was to evaluate the effect of non-thermal atmospheric plasma (NTAP) treatment on prevention of peritoneal adhesions. Materials and Methods: Sixteen male CD-1 mice were randomly divided into two groups: control and plasma. Excisional and abrasion adhesion models were generated on the peritoneal side wall and cecum, respectively. Ten days after creating adhesion models, mice were sacrificed and adhesion formations were evaluated macroscopically using Knightly's and Linsky's grading systems to assess the intensity and extent of adhesions, respectively. Zühlke's grading system was used for microscopic assessment of adhesions. Results: The mean scores for peritoneum and cecum in control group according to Knightly's grading system were determined as 3.3 and 2.6, respectively. In NTAP-treated group, Knightly's score was determined as 1.6 and 0.5 for peritoneum and cecum, respectively. NTAP treatment reduced Linsky's score from 3.8 to 1.3 and 2.1 to 1.1 on peritoneum and cecum. Finally, in microscopic evaluation, NTAP treatment reduced Zühlke's score from 3.4 to 1.5 and 2.6 to 1.3 for peritoneum and cecum, respectively. Conclusions: The results of the present proof of concept study suggest that NTAP could be a novel method to reduce and/or prevent the formation of peritoneal adhesions after abdominopelvic surgeries.

A Critical Review on Selected External Physical Cues and Modulation of Cell Behavior: Magnetic Nanoparticles, Non-thermal Plasma and Lasers

Physics-based biomedical approaches have proved their importance for the advancement of medical sciences and especially in medical diagnostics and treatments. Thus, the expectations regarding development of novel promising physics-based technologies and tools are very high. This review describes the latest research advances in biomedical applications of external physical cues. We overview three distinct topics: using high-gradient magnetic fields in nanoparticle-mediated cell responses; non-thermal plasma as a novel bactericidal agent; highlights in understanding of cellular mechanisms of laser irradiation. Furthermore, we summarize the progress, challenges and opportunities in those directions. We also discuss some of the fundamental physical principles involved in the application of each cue. Considerable technological success has been achieved in those fields. However, for the successful clinical translation we have to understand the limitations of technologies. Importantly, we identify the misconceptions pervasive in the discussed fields.