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

Tissue adhesion after surgical interventions (Review)

Tissue adhesion after surgical procedures is a common postoperative complication that affects a significant number of patients across all surgical disciplines. In pelvic surgical procedures, second-look surgeries have revealed adhesions in more than half of all patients weeks to several months after surgery. Adhesions can be asymptomatic, but they can also cause a wide range of complications, such as severe pain, nausea, vomiting, constipation, ileus and reproductive dysfunction. Undetected adhesions that lead to problems in subsequent surgical interventions are also of high clinical importance. Lysis of these adhesions before the actual surgery leads to loss of time and possible additional complications, such as trocar injuries in laparoscopies or inadvertent enterotomies during adhesiolysis, during the originally planned intervention. The health care associated with adhesion-related problems are significant. Because of the widely varying manifestations of symptoms, the already concerning figure of patients with significant adhesions is likely to increase. Outpatient healthcare expenditures are further increased because of undetected adhesions. Adhesions therefore represent a major surgical and health economic problem; however, yet there are currently few options for prophylaxis and treatment.

Plasma-activated solutions prevent peritoneal adhesion formation by regulating eNOS expression in mesothelial cells

INTRODUCTION

Peritoneal adhesions cause significant morbidity due to limited therapeutic options. Current strategies are limited by inconsistent efficacy and potential side effects. Plasma-activated solutions (PAS) exhibit anti-inflammatory and healing promoting properties with good safety, their efficacy in preventing peritoneal adhesions remains further investigation.

OBJECTIVES

This study aimed to investigate the therapeutic potential of PAS in preventing peritoneal adhesion formation and to elucidate its mechanisms.

METHODS

Two murine peritoneal adhesion models ("ischemic button" and "cecum-peritoneum abrasion") were established. Human peritoneal mesothelial cell was treated with LPS or TGF-β1 to model apoptosis and mesothelial-to-mesenchymal transition (MMT) in vitro. Apoptosis was quantified via flow cytometry and western blotting; ROS levels were assessed using immunofluorescence staining. MMT markers (western blotting) and inflammatory cytokines (ELISA) were analyzed. Histological evaluation included Masson's trichrome and immunofluorescence staining.

RESULTS

PAS-2 min significantly reduced adhesion scores compared to PBS controls (ischemic button: 6.250 ± 1.389 vs. 2.5 ± 2.268; abrasion: 7.333 ± 1.033 vs. 1.633 ± 1.333, p < 0.01). In vitro, PAS treatment decreased LPS-induced apoptosis in mesothelial cells by 8.14 % (flow cytometry: 39.10 % ± 1.47 % vs. 30.96 % ± 1.73 %, p < 0.01) and suppressed MMT markers, with N-cadherin and Vimentin expression reduced by 1.46-fold (p < 0.05) and 1.62-fold (p < 0.05). PAS also attenuated oxidative stress, decreasing general ROS levels by 3-fold (p < 0.001) and mitochondrial ROS (mtROS) by 2-fold (p < 0.01). Mechanistically, reactive nitrogen species (RNS) in PAS restored eNOS expression, attenuating apoptosis and MMT in mesothelial cells.

CONCLUSION

This study demonstrates that PAS prevents peritoneal adhesions via RNS-mediated eNOS restoration, suppressing oxidative stress, apoptosis, and MMT. These findings position PAS as a novel and promising therapy for adhesion prevention, warranting clinical translation.

Advancing chronic and acute wound healing with cold atmospheric plasma: cellular and molecular mechanisms, benefits, risks, and future directions

Chronic and acute wounds represent significant challenges in healthcare, often leading to prolonged recovery times and increased complications. While chronic wounds, such as diabetic foot ulcers and venous leg ulcers, persist due to underlying conditions and biofilm formation, acute wounds, including surgical incisions and burns, can also benefit from innovative therapeutic approaches. Cold atmospheric plasma (CAP) has emerged as a promising non-invasive therapy capable of enhancing wound healing outcomes across both wound types. This review examines the cellular and molecular mechanisms by which CAP promotes wound repair, focusing on its modulation of inflammation, stimulation of angiogenesis, facilitation of tissue remodeling, and antimicrobial effects, which can potentially be used in regenerative medicine. CAP generates reactive oxygen and nitrogen species that influence key cellular processes, accelerating tissue regeneration while reducing bacterial load and preventing biofilm formation. Clinical applications of CAP have demonstrated its efficacy in improving wound healing metrics for both chronic and acute wounds. Despite promising results, translating CAP into routine clinical practice requires addressing challenges such as standardizing treatment protocols, assessing long-term safety, and developing portable devices. Future research should prioritize optimizing CAP parameters and exploring combination therapies to maximize its therapeutic potential. Overall, CAP represents a safe, effective, and versatile modality in wound management, with the potential to significantly improve patient outcomes in both chronic and acute wound care.

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.

Human tissue-resident peritoneal macrophages reveal resistance towards oxidative cell stress induced by non-invasive physical plasma

In the context of multimodal treatments for abdominal cancer, including procedures such as cytoreductive surgery and intraperitoneal chemotherapy, recurrence rates remain high, and long-term survival benefits are uncertain due to post-operative complications. Notably, treatment-limiting side effects often arise from an uncontrolled activation of the immune system, particularly peritoneally localized macrophages, leading to massive cytokine secretion and phenotype changes. Exploring alternatives, an increasing number of studies investigated the potential of plasma-activated liquids (PAL) for adjuvant peritoneal cancer treatment, aiming to mitigate side effects, preserve healthy tissue, and reduce cytotoxicity towards non-cancer cells. To assess the non-toxicity of PAL, we isolated primary human macrophages from the peritoneum and subjected them to PAL exposure. Employing an extensive methodological spectrum, including flow cytometry, Raman microspectroscopy, and DigiWest protein analysis, we observed a pronounced resistance of macrophages towards PAL. This resistance was characterized by an upregulation of proliferation and anti-oxidative pathways, countering PAL-derived oxidative stress-induced cell death. The observed cellular effects of PAL treatment on human tissue-resident peritoneal macrophages unveil a potential avenue for PAL-derived immunomodulatory effects within the human peritoneal cavity. Our findings contribute to understanding the intricate interplay between PAL and macrophages, shedding light on the promising prospects for PAL in the adjuvant treatment of peritoneal cancer.

Plasma Device Functions and Tissue Effects in the Female Pelvis-A Systematic Review

Medical use of (non-)thermal plasmas is an emerging field in gynaecology. However, data on plasma energy dispersion remain limited. This systematic review presents an overview of plasma devices, fields of effective application, and impact of use factors and device settings on tissues in the female pelvis, including the uterus, ovaries, cervix, vagina, vulva, colon, omentum, mesenterium, and peritoneum. A search of the literature was performed on 4 January 2023 in the Medline Ovid, Embase, Cochrane, Web of Science, and Google Scholar databases. Devices were classified as plasma-assisted electrosurgery (ES) using electrothermal energy, neutral argon plasma (NAP) using kinetic particle energy, or cold atmospheric plasma (CAP) using non-thermal biochemical reactions. In total, 8958 articles were identified, of which 310 were scanned, and 14 were included due to containing quantitative data on depths or volumes of tissues reached. Plasma-assisted ES devices produce a thermal effects depth of <2.4 mm. In turn, NAP effects remained superficial, <1.0 mm. So far, the depth and uniformity of CAP effects are insufficiently understood. These data are crucial to achieve complete treatment, reduce recurrence, and limit damage to healthy tissues (e.g., prevent perforations or preserve parenchyma). Upcoming and potentially high-gain applications are discussed, and deficits in current evidence are identified.

Opportunities of Electronic and Optical Sensors in Autonomous Medical Plasma Technologies

Low temperature plasma technology is proving to be at the frontier of emerging medical technologies with real potential to overcome escalating healthcare challenges including antimicrobial and anticancer resistance. However, significant improvements in efficacy, safety, and reproducibility of plasma treatments need to be addressed to realize the full clinical potential of the technology. To improve plasma treatments recent research has focused on integrating automated feedback control systems into medical plasma technologies to maintain optimal performance and safety. However, more advanced diagnostic systems are still needed to provide data into feedback control systems with sufficient levels of sensitivity, accuracy, and reproducibility. These diagnostic systems need to be compatible with the biological target and to also not perturb the plasma treatment. This paper reviews the state-of-the-art electronic and optical sensors that might be suitable to address this unmet technological need, and the steps needed to integrate these sensors into autonomous plasma systems. Realizing this technological gap could facilitate the development of next-generation medical plasma technologies with strong potential to yield superior healthcare outcomes.

Raman microspectroscopy identifies fibrotic tissues in collagen-related disorders via deconvoluted collagen type I spectra

Fibrosis is a consequence of the pathological remodeling of extracellular matrix (ECM) structures in the connective tissue of an organ. It is often caused by chronic inflammation, which over time, progressively leads to an excess deposition of collagen type I (COL I) that replaces healthy tissue structures, in many cases leaving a stiff scar. Increasing fibrosis can lead to organ failure and death; therefore, developing methods that potentially allow real-time monitoring of early onset or progression of fibrosis are highly valuable. In this study, the ECM structures of diseased and healthy human tissue from multiple organs were investigated for the presence of fibrosis using routine histology and marker-independent Raman microspectroscopy and Raman imaging. Spectral deconvolution of COL I Raman spectra allowed the discrimination of fibrotic and non-fibrotic COL I fibers. Statistically significant differences were identified in the amide I region of the spectral subpeak at 1608 cm^-1, which was deemed to be representative for structural changes in COL I fibers in all examined fibrotic tissues. Raman spectroscopy-based methods in combination with this newly discovered spectroscopic biomarker potentially offer a diagnostic approach to non-invasively track and monitor the progression of fibrosis. STATEMENT OF SIGNIFICANCE: Current diagnosis of fibrosis still relies on histopathological examination with invasive biopsy procedures. Although, several non-invasive imaging techniques such as positron emission tomography, single-photon emission computed tomography and second harmonic generation are gradually employed in preclinical or clinical studies, these techniques are limited in spatial resolution and the morphological interpretation highly relies on individual experience and knowledge. In this study, we propose a non-destructive technique, Raman microspectroscopy, to discriminate fibrotic changes of collagen type I based on a molecular biomarker. The changes of the secondary structure of collagen type I can be identified by spectral deconvolution, which potentially can provide an automatic diagnosis for fibrotic tissues in the clinical applicaion.

Conductive Gas Plasma Treatment Augments Tumor Toxicity of Ringer's Lactate Solutions in a Model of Peritoneal Carcinomatosis

Reactive species generated by medical gas plasma technology can be enriched in liquids for use in oncology targeting disseminated malignancies, such as metastatic colorectal cancer. Notwithstanding, reactive species quantities depend on the treatment mode, and we recently showed gas plasma exposure in conductive modes to be superior for cancer tissue treatment. However, evidence is lacking that such a conductive mode also equips gas plasma-treated liquids to confer augmented intraperitoneal anticancer activity. To this end, employing atmospheric pressure argon plasma jet kINPen-treated Ringer's lactate (oxRilac) in a CT26-model of colorectal peritoneal carcinomatosis, we tested repeated intraabdominal injection of such remotely or conductively oxidized liquid for antitumor control and immunomodulation. Enhanced reactive species formation in conductive mode correlated with reduced tumor burden in vivo, emphasizing the advantage of conduction over the free mode for plasma-conditioned liquids. Interestingly, the infiltration of lymphocytes into the tumors was equally enhanced by both treatments. However, significantly lower levels of interleukin (IL)4 and IL13 and increased levels of IL2 argue for a shift in intratumoral T-helper cell subpopulations correlating with disease control. In conclusion, our data argue for using conductively over remotely prepared plasma-treated liquids for anticancer treatment.

Cold Argon Athmospheric Plasma for Biomedicine: Biological Effects, Applications and Possibilities

Currently, plasma medicine is a synthetic direction that unites the efforts of specialists of various profiles. For the successful formation of plasma medicine, it is necessary to solve a large complex of problems, including creating equipment for generating cold plasma, revealing the biological effects of this effect, as well as identifying and justifying the most promising areas of its application. It is known that these biological effects include antibacterial and antiviral activity, the ability to stimulate hemocoagulation, pro-regenerative properties, etc. The possibility of using the factor in tissue engineering and implantology is also shown. Based on this, the purpose of this review was to form a unified understanding of the biological effects and biomedical applications of argon cold plasma. The review shows that cold plasma, like any other physical and chemical factors, has dose dependence, and the variable parameter in this case is the exposure of its application. One of the significant characteristics determining the specificity of the cold plasma effect is the carrier gas selection. This gas carrier is not just an ionized medium but modulates the response of biosystems to it. Finally, the perception of cold plasma by cellular structures can be carried out by activating a special molecular biosensor, the functioning of which significantly depends on the parameters of the medium (in the field of plasma generation and the cell itself). Further research in this area can open up new prospects for the effective use of cold plasma.