Opposite effects of non-thermal plasma on cell migration and collagen production in keloid and normal fibroblasts

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.

Comparing Redox and Intracellular Signalling Responses to Cold Plasma in Wound Healing and Cancer

Cold plasma (CP) is an ionised gas containing excited molecules and ions, radicals, and free electrons, and which emits electric fields and UV radiation. CP is potently antimicrobial, and can be applied safely to biological tissue, birthing the field of plasma medicine. Reactive oxygen and nitrogen species (RONS) produced by CP affect biological processes directly or indirectly via the modification of cellular lipids, proteins, DNA, and intracellular signalling pathways. CP can be applied at lower levels for oxidative eustress to activate cell proliferation, motility, migration, and antioxidant production in normal cells, mainly potentiated by the unfolded protein response, the nuclear factor-erythroid factor 2-related factor 2 (Nrf2)-activated antioxidant response element, and the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway, which also activates nuclear factor-kappa B (NFκB). At higher CP exposures, inactivation, apoptosis, and autophagy of malignant cells can occur via the degradation of the PI3K/Akt and mitogen-activated protein kinase (MAPK)-dependent and -independent activation of the master tumour suppressor p53, leading to caspase-mediated cell death. These opposing responses validate a hormesis approach to plasma medicine. Clinical applications of CP are becoming increasingly realised in wound healing, while clinical effectiveness in tumours is currently coming to light. This review will outline advances in plasma medicine and compare the main redox and intracellular signalling responses to CP in wound healing and cancer.

Liquid plasma promotes angiogenesis through upregulation of endothelial nitric oxide synthase-induced extracellular matrix metabolism: potential applications of liquid plasma for vascular injuries

BACKGROUND

Applications of nonthermal plasma have expanded beyond the biomedical field to include antibacterial, anti-inflammatory, wound healing, and tissue regeneration. Plasma enhances epithelial cell repair; however, the potential damage to deep tissues and vascular structures remains under investigation.

RESULT

This study assessed whether liquid plasma (LP) increased nitric oxide (NO) production in human umbilical vein endothelial cells by modulating endothelial NO synthase (eNOS) phosphorylation and potential signaling pathways. First, we developed a liquid plasma product and confirmed the angiogenic effect of LP using the Matrigel plug assay. We found that the NO content increased in plasma-treated water. NO in plasma-treated water promoted cell migration and angiogenesis in scratch and tube formation assays via vascular endothelial growth factor mRNA expression. In addition to endothelial cell proliferation and migration, LP influenced extracellular matrix metabolism and matrix metalloproteinase activity. These effects were abolished by treatment with NG-L-monomethyl arginine, a specific inhibitor of NO synthase. Furthermore, we investigated the signaling pathways mediating the phosphorylation and activation of eNOS in LP-treated cells and the role of LKB1-adenosine monophosphate-activated protein kinase in signaling. Downregulation of adenosine monophosphate-activated protein kinase by siRNA partially inhibited LP-induced eNOS phosphorylation, angiogenesis, and migration.

CONCLUSION

The present study suggests that LP treatment may be a novel strategy for promoting angiogenesis in vascular damage. Video Abstract.

An Atmospheric Plasma Jet Induces Expression of Wound Healing Genes in Progressive Burn Wounds in a Comb Burn Rat Model: A Pilot Study

Burn-related injuries are devastating injuries with a high mortality rate that affect people of all ages worldwide. We assessed the effectiveness of plasma jet treatment in altering the expression of genes involved in wound healing in a prospective longitudinal observational animal study. Six male Sprague-Dawley rats weighing 350 g were used, and burn wounds were made by applying a preheated brass comb (100°C) to the back of the rats, resulting in four full-thickness burn wounds separated by three interspaces. A total of 18 burn wounds were induced on three rats. One side of the burn, on each rat received plasma treatment (plasma group), while the other side did not (control group). The interspaces were subjected to the plasma jet for 2 minutes per day until 7 days post-wounding. Plasma treatment significantly decreased the expression of proinflammatory cytokines. Furthermore, an increase in the expression of anti-inflammatory cytokines was observed in the plasma group. We showed that plasma jet treatment could improve burn wound healing by altering the expression of genes involved in the development of wound healing.

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

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

The JAK-STAT pathway in keloid pathogenesis: a systematic review with qualitative synthesis

Keloid tissues contain inflammatory cells and upregulated pro-inflammatory cytokines. The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway mediate cellular responses to these cytokines. We performed a systematic review on the role of the JAK-STAT pathway in keloid pathogenesis and the evidence for JAK-STAT inhibitors in keloid treatment. The search combined the terms (1) keloid and (2) JAK or TYK or STAT and included MeSH terms and synonyms. Two reviewers screened the articles and assessed the full texts on eligibility. Data were collected on the tested drugs and molecules, the type of cells and tissues used in the experiments, and study findings on the association between the JAK-STAT pathway and keloid cells and tissues. A total of twenty preclinical studies were included. Eleven preclinical studies proved that STAT3 expression and phosphorylation are enhanced in keloid tissue and keloid fibroblasts. Thirteen different JAK and/or STAT inhibitors were investigated. Tested drugs inhibited keloid progression as demonstrated by different processes, including reduced collagen production, cell proliferation and migration, increased cell cycle arrest and apoptosis, enhanced antioxidant responses, decreased (paracrine) signalling, and decreased profibrotic gene expression. No clinical studies have been published to date. Preclinical studies indicate a role for the JAK-STAT pathway in keloid pathogenesis and a potential role for JAK-STAT inhibitors in keloid treatment. The effect of these drugs should be further investigated on relevant biomarkers in a human keloid skin model, preferably including immune cells besides keloid fibroblasts and keratinocytes and in clinical studies.

Efficacy and safety of the innovative cold atmospheric-pressure plasma technology in the treatment of keloid: A randomized controlled trial

BACKGROUND

Keloid (KD) treatment is challenging for both physicians and patients. It can be functional debilitating and psychologically distressing. Available current therapeutics modalities give inconsistently effective results.

OBJECTIVES

To evaluate the efficacy and safety of innovative cold atmospheric plasma (CAP) technology in the treatment of keloid.

METHODS

This prospective, randomized control trial, the assessor-blinded trial, includes 18 patients with keloids. The keloid lesion was divided into two halves. One side was randomly treated with CAP technology biweekly on the same treated side for five sessions with a follow-up 30 days after finishing the final treatment. Another half was left untreated as a control. Efficacy assessment using POSAS, VSS, Patients' satisfaction scale, Antera 3D® skin imaging system. The safety assessment using VAS and adverse effects monitoring was completed.

RESULTS

Objective assessment using Antera 3D® skin imaging system (Miravex, Dublin, Ireland) showed statistically significant improvement (p-value <0.05) on the treated side compared with the untreated side in all parameters, color, melanin, hemoglobin, texture, except for volume. POSAS, patient, and observer overall opinion score, and patient and observer total score in the summary of all rated characteristics, comparing the treated and untreated areas, showed a statistically significant reduction in all parameters after two treatments (*p-value <0.05). VSS showed statistically significant improvement after the second treatment and continued to the last follow-up. Most patients rated satisfaction scales up to 72.2% as moderate improvement, 11.1% as great improvement, 11.1% as slight improvement, and 5.6% as no change. The adverse effect was only a small scab in one patient.

CONCLUSION

CAP technology could be considered an alternative treatment for keloid offering mild-to-moderate improvement with minimal side effects.

Therapeutic Effects of Cold Atmospheric Plasma on Solid Tumor

Cancer is a devastating disease, and there is no particularly effective treatment at present. Recently, a new treatment, cold atmospheric plasma (CAP), has been proposed. At present, CAP is confirmed to have selective killing effect on tumor by many studies in vitro and in vivo. A targeted literature search was carried out on the study of cold atmospheric plasma. Through analysis and screening, a narrative review approach was selected to describe therapeutic effects of cold atmospheric plasma on solid tumor. According to the recent studies on plasma, some hypothetical therapeutic schemes of CAP are proposed in this paper. The killing mechanism of CAP on solid tumor is expounded in terms of the selectivity of CAP to tumor, the effects of CAP on cells, tumor microenvironment (TME) and immune system. CAP has many effects on solid tumors, and these effects are dose-dependent. The effects of optimal doses of CAP on solid tumors include killing tumor cells, inhibiting non-malignant cells and ECM in TME, affecting the communication between tumor cells, and inducing immunogenic death of tumor cells. In addition, several promising research directions of CAP are proposed in this review, which provide guidance for future research.

TIP60 acts as a regulator of genes involved in filopodia formation and cell migration during wound healing

Wound healing is a complex phenomenon that requires coordination of numerous molecular and cellular changes to facilitate timely and efficient repair of the damaged tissue. Although many of these molecular pathways have been detailed, others remain to be elucidated. In the present work, we show for the first time, roles for the acetyltransferase TIP60 and nuclear receptor transcription factor PXR in this process, participating in wound healing by altering actin dynamics and cellular motility. We found that in response to wound-injury, TIP60 induces rapid formation of filopodia at the wounded cell front, leading to enhanced cell migration and faster closure of the wound. Further, qPCR analysis revealed heightened expression of Cdc42 and ROCK1 genes, key regulators involved in filopodia formation and actin reorganization, exclusively in TIP60-PXR-expressing cells upon wound-induction. We also performed ChIP assays to confirm the context-specific binding of TIP60 on the ROCK1 promoter and demonstrated that the TIP60 chromodomain is essential for loading of the TIP60–PXR complex onto the chromatin. Results from immunoprecipitation assays revealed that during the wounded condition, TIP60 alters the chromatin microenvironment by specifically acetylating histones H2B and H4, thereby modulating the expression of target genes. Overall, findings of this study show that TIP60 is a novel regulator of the wound healing process by regulating the expression of wound repair-related genes.

Cell Type-Specific Anti-Adhesion Properties of Peritoneal Cell Treatment with Plasma-Activated Media (PAM)

Postoperative abdominal adhesions are responsible for serious clinical disorders. Administration of plasma-activated media (PAM) to cell type-specific modulated proliferation and protein biosynthesis is a promising therapeutic strategy to prevent pathological cell responses in the context of wound healing disorders. We analyzed PAM as a therapeutic option based on cell type-specific anti-adhesive responses. Primary human peritoneal fibroblasts and mesothelial cells were isolated, characterized and exposed to different PAM dosages. Cell type-specific PAM effects on different cell components were identified by contact- and marker-independent Raman imaging, followed by thorough validation by specific molecular biological methods. The investigation revealed cell type-specific molecular responses after PAM treatment, including significant cell growth retardation in peritoneal fibroblasts due to transient DNA damage, cell cycle arrest and apoptosis. We identified a therapeutic dose window wherein specifically pro-adhesive peritoneal fibroblasts were targeted, whereas peritoneal mesothelial cells retained their anti-adhesive potential of epithelial wound closure. Finally, we demonstrate that PAM treatment of peritoneal fibroblasts reduced the expression and secretion of pro-adhesive cytokines and extracellular matrix proteins. Altogether, we provide insights into biochemical PAM mechanisms which lead to cell type-specific pro-therapeutic cell responses. This may open the door for the prevention of pro-adhesive clinical disorders.

The Anti-Fibrotic Effect of Cold Atmospheric Plasma on Localized Scleroderma In Vitro and In Vivo

Cold Atmospheric Plasma (CAP) has shown promising results in the treatment of various skin diseases. The therapeutic effect of CAP on localized scleroderma (LS), however, has not yet been evaluated. We investigated the effects of CAP on LS by comparing human normal fibroblasts (hNF), human TGF-β-activated fibroblasts (hAF), and human localized scleroderma-derived fibroblasts (hLSF) after direct CAP treatment, co-cultured with plasma-treated human epidermal keratinocytes (hEK) and with an experimental murine model of scleroderma. In hAF and hLSF, 2 min CAP treatment with the MicroPlaSterβ^® plasma torch did not affect pro-fibrotic gene expression of alpha smooth muscle actin, fibroblast activating protein, and collagen type I, however, it promoted re-expression of matrix metalloproteinase 1. Functionally, CAP treatment reduced cell migration and stress fiber formation in hAF and hLSF. The relevance of CAP treatment was confirmed in an in vivo model of bleomycin-induced dermal fibrosis. In this model, CAP-treated mice showed significantly reduced dermal thickness and collagen deposition as well as a decrease in both alpha smooth muscle actin-positive myofibroblasts and CD68-positive macrophages in the affected skin in comparison to untreated fibrotic tissue. In conclusion, this study provides the first evidence for the successful use of CAP for treating LS and may be the basis for clinical trials including patients with LS.

Cold Atmospheric Plasma Promotes the Immunoreactivity of Granulocytes In Vitro

Cold atmospheric plasma (CAP) reduces bacteria and interacts with tissues and cells, thus improving wound healing. The CAP-related induction of neutrophils was recently described in stained sections of wound tissue in mice. Consequently, this study aimed to examine the functionality of human polymorphonuclear cells (PMN)/granulocytes through either a plasma-treated solution (PTS) or the direct CAP treatment with different plasma modes and treatment durations. PTS analysis yielded mode-dependent differences in the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) after CAP treatment. Live-cell imaging did not show any chemo-attractive or NETosis-inducing effect on PMNs treated with PTS. The time to maximum ROS production (TmaxROS) in PMNs was reduced by PTS and direct CAP treatment. PMNs directly treated with CAP showed an altered cell migration dependent on the treatment duration as well as decreased TmaxROS without inducing apoptosis. Additionally, flow cytometry showed enhanced integrin and selectin expression, as a marker of activation, on PMN surfaces. In conclusion, the modification of PMN immunoreactivity may be a main supporting mechanism for CAP-induced improvement in wound healing.

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.

Wound Healing Effect of Nonthermal Atmospheric Pressure Plasma Jet on a Rat Burn Wound Model: A Preliminary Study

Worldwide, an estimated 6 million patients seek medical attention for burns annually. Various treatment methods and materials have been investigated and developed to enhance burn wound healing. Recently, a new technology, plasma medicine, has emerged to offer new solutions in wound care. As the development of plasma medicine has shown benefit in wound healing, we aimed to assess the effects of plasma medicine on burn wounds. To investigate the effectiveness of a nonthermal atmospheric pressure plasma jet (NAPPJ) for burn wound treatment on a brass comb burn wound rat model. Burn wounds were made by applying a preheated brass comb (100°C) for 2 minutes, which resulted in four full-thickness burn wounds separated by three interspaces. Interspaces were exposed to NAPPJ treatment for 2 minutes and morphological changes and neutrophil infiltration were monitored at 0, 4, and 7 days post-wounding. The percentage of necrotic interspace was higher in the control group than in the plasma-treated group (51.8 ± 20.5% vs 31.5 ± 19.0%, P < .001). Moreover, the exposure of interspace to NAPPJ greatly reduced the number of infiltrating neutrophils. In addition, the percentage of interspace that underwent full-thickness necrosis in the plasma-treated group was smaller than that in the control group (28% vs 67%). NAPPJ exposure on interspaces has a positive effect on burn wounds leading to wound healing by reducing burn injury progression.

The emerging potential of cold atmospheric plasma in skin biology

The maintenance of skin integrity is crucial to ensure the physiological barrier against exogenous compounds, microorganisms and dehydration but also to fulfill social and aesthetic purposes. Besides the development of new actives intended to enter a formulation, innovative technologies based on physical principles have been proposed in the last years. Among them, Cold Atmospheric Plasma (CAP) technology, which already showed interesting results in dermatology, is currently being studied for its potential in skin treatments and cares. CAP bio-medical studies gather several different expertise ranging from physics to biology through chemistry and biochemistry, making this topic hard to pin. In this review we provide a broad survey of the interactions between CAP and skin. In the first section, we tried to give some fundamentals on skin structure and physiology, related to its essential functions, together with the main bases on cold plasma and its physicochemical properties. In the following parts we dissected and analyzed each CAP parameter to highlight the already known and the possible effects they can play on skin. This overview aims to get an idea of the potential of cold atmospheric plasma technology in skin biology for the future developments of dermo-cosmetic treatments, for example in aging prevention.

Treatment of keloids through Runx2 siRNA‑induced inhibition of the PI3K/AKT signaling pathway

Keloids are a skin fibroproliferative condition characterized by the hyperproliferation of fibroblasts and the excessive deposition of extracellular matrix (ECM) components. Previous studies have determined that Caveolin-1 controlled hyperresponsiveness to mechanical stimuli through Runt-related transcription factor 2 (Runx2) activation in keloids. However, the molecular mechanism of Runx2 regulating the pathological progression of keloids has not been elucidated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that most of the differentially expressed genes (DEGs), including Runx2, were significantly enriched in the biological processes ‘Positive regulation of cell proliferation’, in the cellular components ‘Extracellular matrix’, in the molecular functions ‘Extracellular matrix structural constituents’ and in the KEGG ‘PI3K-Akt signaling pathway’. The aim of the present study was to investigate the expression levels of the Runx2 in human keloid tissues and primary human keloid fibroblasts (HKFs), and to determine the underlying molecular mechanisms involved in the fibrotic roles of Runx2 in keloid formation. Runx2 expression levels were analyzed in patient keloid tissues and HKFs using western blotting, reverse transcription-quantitative PCR (RT-qPCR) and immunofluorescence microscopy. Primary HKFs were transfected with a small interfering RNA (si) specifically targeting Runx2 (si-Runx2). Subsequently, Cell Counting Kit-8, wound healing and Transwell assays, flow cytometry, RT-qPCR and western blotting were applied to evaluate the proliferation, migration, apoptosis, ECM deposition and PI3K/AKT signaling pathway of HKFs, respectively. In addition, western blotting was also used to determine the expression levels of phosphorylated AKT and PI3K in HKFs. The results revealed that Runx2 expression levels were upregulated in keloid tissues and primary HKFs compared with the normal skin tissues and human normal fibroblasts. Following the transfection with si-Runx2, the proliferative and migratory abilities of HKFs were significantly reduced and the apoptotic rate was increased. The expression levels of type I, type III collagen, fibronectin, and α-smooth muscle actin were downregulated in si-Runx2-transfected cells, which was hypothesized to occur through following the downregulation of the phosphorylation levels of PI3K and AKT. In conclusion, the findings of the present study indicated that Runx2 silencing in HKFs might significantly inhibit the cell proliferation, migration and the expression levels of ECM-related proteins, and promote apoptosis via suppressing the PI3K/AKT signaling pathway. Thus, Runx2 siRNA treatment may reverse the pathological phenotype of keloids through the inhibition of PI3K/AKT signaling in patients.

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

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

The effect of non-thermal atmospheric pressure plasma application on wound healing after gingivectomy

Recent studies have indicated the potential benefits of Non-thermal atmospheric pressure plasma (NTAPP) as a novel therapeutic approach. The purpose of the current study was thus to assess the effect of NTAPP on gingival wound healing. Fifteen patients with bilaterally symmetrical gingival hyperplasia were included in the study. After gingivectomy and gingivoplasty, the left-hand side of the symmetrical surgical area was irradiated with NTAPP (plasma jet kINPen 11). Digital photographs of the gingival wounds were taken at baseline and days 3, 7, and 14. Wound epithelialisation was evaluated. Landry Wound Healing Index (WHI) scores and visual analogue scale (VAS) scores were also recorded. There were significant differences between the epithelialisation of the NTAPP-treated sites and the control sites after the surgical procedures. The NTAPP-treated sites had significantly smaller stained surface areas compared with the control sites on the 3rd, 7^th , and 14th days (P < .05). The NTAPP-treated sites had better WHI scores than the control sites throughout the follow-up period (P < .05). It can be concluded that NTAPP enhances epithelialisation and stimulates wound healing after gingivectomy and gingivoplasty. However, further clinical studies with larger sample sizes are needed to determine the exact benefits of NTAPP for gingival wound healing.

Identification and analysis of dysregulated lncRNA and associated ceRNA in the pathogenesis of keloid

Background

Keloid is an excessive fibrosis disease caused by the abnormal proliferation of collagen fibers following trauma. Previous studies have shown that genetic factors have been considered to play important roles in keloid formation. This study is aimed to investigate the regulatory network of messenger RNAs (mRNAs) microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in keloid, and identifying its key biomarkers.

Methods

We performed RNA-seq and miRNA-seq on keloid and normal skin samples. Sequencing datasets were analyzed by bioinformatics. Gene ontology (GO) and pathway analysis presented the characteristics of associated protein-coding genes. Differentially expressed ceRNAs were validated by quantitative reverse transcriptase-PCR (qRT-PCR).

Results

We identified a total of 319 lncRNAs, 1,533 mRNAs and 40 miRNAs as keloid-specific RNAs. Both the GO biological processes and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed for 1,219 specific genes with differentially expressed mRNAs. Then, with 509 key lncRNAs, 25 miRNAs, and 94 mRNAs, we constructed a ceRNA network and explored any potential underlying mechanisms. In the regulation of the actin cytokeleton pathway, we validated 2 pairs of ceRNAs EGFR/miR-370-3p/lnc-GLB1L-1 and ITGB5/ miR-204/ lnc-CASP9-3 in another sample size in keloid.

Conclusions

Through RNA-seq and miRNA-seq, we identified keloid-associated lncRNAs, mRNAs and miRNAs, which can be used as potential therapeutic targets and biomarkers for keloid. Our study may lay a foundation for future pathogenesis studies.

Molecular Mechanisms of the Efficacy of Cold Atmospheric Pressure Plasma (CAP) in Cancer Treatment

Recently, the potential use of cold atmospheric pressure plasma (CAP) in cancer treatment has gained increasing interest. Especially the enhanced selective killing of tumor cells compared to normal cells has prompted researchers to elucidate the molecular mechanisms for the efficacy of CAP in cancer treatment. This review summarizes the current understanding of how CAP triggers intracellular pathways that induce growth inhibition or cell death. We discuss what factors may contribute to the potential selectivity of CAP towards cancer cells compared to their non-malignant counterparts. Furthermore, the potential of CAP to trigger an immune response is briefly discussed. Finally, this overview demonstrates how these concepts bear first fruits in clinical applications applying CAP treatment in head and neck squamous cell cancer as well as actinic keratosis. Although significant progress towards understanding the underlying mechanisms regarding the efficacy of CAP in cancer treatment has been made, much still needs to be done with respect to different treatment conditions and comparison of malignant and non-malignant cells of the same cell type and same donor. Furthermore, clinical pilot studies and the assessment of systemic effects will be of tremendous importance towards bringing this innovative technology into clinical practice.

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.

Cytocompatibility of Titanium, Zirconia and Modified PEEK after Surface Treatment Using UV Light or Non-Thermal Plasma

A number of modifications have been developed in order to enhance surface cytocompatibility for prosthetic support of dental implants. Among them, ultraviolet (UV) light and non-thermal plasma (NTP) treatment are promising methods. The objective of this study was to compare the effects of UV light and NTP on machined titanium, zirconia and modified polyetheretherketone (PEEK, BioHPP) surfaces in vitro. Machined samples of titanium, zirconia and BioHPP were treated by UV light and NTP of argon or oxygen for 12 min each. Non-treated disks were set as controls. A mouse fibroblast and a human gingival fibroblast cell line were used for in vitro experiments. After 2, 24 and 48 h of incubation, the attachment, viability and cytotoxicity of cells on surfaces were assessed. Results: Titanium, zirconia and BioHPP surfaces treated by UV light and oxygen plasma were more favorable to the early attachment of soft-tissue cells than non-treated surfaces, and the number of cells on those treated surfaces was significantly increased after 2, 24 and 48 h of incubation (p < 0.05). However, the effects of argon plasma treatment on the cytocompatibility of soft tissue cells varied with the type of cells and the treated material. UV light and oxygen plasma treatments may improve the attachment of fibroblast cells on machined titanium, zirconia and PEEK surfaces, that are materials for prosthetic support of dental implants.

GnRH impairs diabetic wound healing through enhanced NETosis

It has been reported that neutrophil extracellular traps (NETs) impair wound healing in diabetes and that inhibiting NET generation (NETosis) improves wound healing in diabetic mice. Gonadotropin-releasing hormone (GnRH) agonists are associated with a greater risk of diabetes. However, the role of GnRH in diabetic wound healing is unclear. We determined whether GnRH-promoted NETosis and induced more severe and delayed diabetic wound healing. A mouse model of diabetes was established using five injections with streptozotocin. Mice with blood glucose levels >250 mg/dL were then used in the experiments. GnRH agonist treatment induced delayed wound healing and increased NETosis at the skin wounds of diabetic mice. In contrast, GnRH antagonist treatment inhibited GnRH agonist-induced delayed wound healing. The expression of NETosis markers PAD4 and citrullinated histone H3 were increased in the GnRH-treated diabetic skin wounds in diabetic mice and patients. In vitro experiments also showed that neutrophils expressed a GnRH receptor and that GnRH agonist treatment increased NETosis markers and promoted phorbol myristate acetate (PMA)-induced NETosis in mouse and human neutrophils. Furthermore, GnRH antagonist treatment suppressed the expression of NETosis markers and PMA-induced NETosis, which were increased by GnRH treatment. These results indicated that GnRH-promoted NETosis and that increased NETosis induced delayed wound healing in diabetic skin wounds. Thus, inhibition of GnRH might be a novel treatment of diabetic foot ulcers.

Nell-1-ΔE, a novel transcript of Nell-1, inhibits cell migration by interacting with enolase-1

NELL-1 is a secreted protein that was originally found to be upregulated in pathologically fusing and fused sutures in non-syndromic unilateral coronal synostosis patients. Apart from the ability of NELL-1 to promote osteogenesis in long and craniofacial bones, NELL-1 reportedly inhibits the formation of several benign and malignant tumors. We previously identified a novel transcript of Nell-1 that lacked a calcium-binding epidermal growth factor (EGF)-like domain compared with full-length Nell-1; this new transcript was named Nell-1-ΔE. Three obvious structural differences between these two isoforms were revealed by homology modeling. Furthermore, the recombinant Nell-1-ΔE protein, but not the full-length Nell-1 protein, inhibited cell migration in vitro. However, full-length Nell-1 and Nell-1-ΔE proteins were present in similar subcellular locations and displayed similar expression patterns in both the intracellular and extracellular spaces. The results from the co-immunoprecipitation and liquid chromatography/tandem mass spectrometry analyses using two cell lines demonstrated that Nell-1-ΔE but not full-length Nell-1 interacted with enolase-1 in the extracellular spaces of both cell lines. The results of wound healing assays using ENO-1-overexpressing cells treated with full-length Nell-1/Nell-1-ΔE suggested that Nell-1-ΔE inhibited cell migration by interacting with ENO-1. Our study indicated that the novel transcript Nell-1-ΔE, but not full-length Nell-1, might be a candidate tumor suppressor factor for basic research and clinical practice.