Comparison of Cold Atmospheric Plasma Devices' Efficacy on Osteosarcoma and Fibroblastic In Vitro Cell Models

BACKGROUND/AIM

Cold atmospheric plasma (CAP) attenuates tumor cell proliferation and induces apoptosis in various cell lines. While exerting marginal effects on non-neoplastic cells this unfolds promising applications in cancer therapy. The aim of the study was to analyse the effects of different CAP sources and application times on osteosarcoma (OS) cells and non-malignant fibroblast cell proliferation.

MATERIALS AND METHODS

U2-OS and 3-T-3 fibroblasts were treated with three different approved medical devices. Carrier gas-treated cells served as controls. Cell proliferation was determined by viable cell count at different time points after treatment.

RESULTS

Control exposed U2-OS and 3-T-3 cells exhibited characteristic cell growth. CAP application of U2-OS and 3-T-3 cells attenuated proliferation rates up to 98%. Attenuation rates varied between cell lines, plasma sources and application times.

CONCLUSION

CAP treatment attenuates cell proliferation of OS cancer cells and fibroblasts in a treatment time-dependent manner, whereby U2-OS cells appeared more sensitive to CAP treatment as 3T3 fibroblasts after 10 sec of treatment.

Cold atmospheric plasma in orthopaedic and urologic tumor therapy

Cold atmospheric plasma (CAP) is a highly reactive ionized physical state thereby provoking divers biological effects. In medical applications, CAP treatment promotes wound healing, provokes immunostimulation, and is antiseptically active. Moreover, CAP interacts with antiproliferative mechanisms suggesting CAP treatment as a promising anticancer strategy. Here we review the current state of science concerning the so far investigated CAP effects on different cancer entities in orthopaedic and urologic oncology.

Peroxiredoxin Expression of Human Osteosarcoma Cells Is Influenced by Cold Atmospheric Plasma Treatment

BACKGROUND/AIM

To evaluate the potential involvement of redox-specific signalling pathways in cold atmospheric plasma (CAP)-induced apoptosis on human osteosarcoma cells.

MATERIALS AND METHODS

Osteosarcoma cell lines were treated with CAP with or without antioxidative agents and seeded in cell culture plates. Cell proliferation was determined by counting viable cells. Carrier gas-treated cells served as control. Peroxiredoxin (PRX) 1-3 expression and secretion were assessed.

RESULTS

CAP treatment exhibited strongly attenuated proliferation rates. This effect was significantly attenuated by the addition of N-acetylcysteine (NAC). CAP-treated cells exhibited an increase of PRX 1 and 2 10 sec after treatment. The ratio of oxidized to reduced PRX1 and PRX2 was significantly altered with increasing cellular concentration of the oxidized dimer.

CONCLUSION

Antioxidant supplementation with NAC increases proliferation of CAP-treated osteosarcoma cells, implicating an involvement of redox signalling. Activation of PRX1 and -2 indicate CAP affects redox homeostasis.

New Treatment Options for Osteosarcoma - Inactivation of Osteosarcoma Cells by Cold Atmospheric Plasma

BACKGROUND/AIM

Cold atmospheric plasma has been shown to inhibit tumor cell growth and induce tumor cell death. The aim of the study was to investigate the effects of cold atmospheric plasma treatment on proliferation of human osteosarcoma cells and to characterize the underlying cellular mechanisms.

MATERIALS AND METHODS

Human osteosarcoma cells (U2-OS and MNNG/HOS) were treated with cold atmospheric plasma and seeded in culture plates. Cell proliferation, p53 and phospho-p53 protein expression and nuclear morphology were assessed.

RESULTS

The treated human osteosarcoma cell lines exhibited attenuated proliferation rates by up to 66%. The cells revealed an induction of p53, as well as phospho-p53 expression, by 2.3-fold and 4.5-fold, respectively, compared to controls. 4',6-diamidino-2-phenylindole staining demonstrated apoptotic nuclear condensation following cold atmospheric plasma treatment.

CONCLUSION

Cold atmospheric plasma treatment significantly attenuated cell proliferation in a preclinical in vitro osteosarcoma model. The resulting increase in p53 expression and phospho-activation in combination with characteristic nuclear changes indicate this was through induction of apoptosis.

Psychosocial burden and desire for support in outpatients with skin cancer

BACKGROUND

An important basis for adequate psycho-oncological and psychosocial care of cancer patients is the regular assessment of their psychosocial distress and thus their need for care. For this purpose, there are numerous questionnaires available. The objective of the present study was to assess whether distressed patients require professional support and which screening instrument outpatients with skin cancer prefer.

PATIENTS AND METHODS

In a cross-sectional survey, we asked outpatients with skin cancer to fill out three questionnaires assessing psychosocial stress, and to indicate which one they considered most adequate. Patients were offered the following three instruments: Hornheide Questionnaire (27 items), Hornheide Screening Instrument (7 items), and the Distress Thermometer. In addition, we inquired about the patients' desire for support.

RESULTS

(1) Comparing subjective distress and patients' declared desire for support revealed a marked divergence. While one-third of the 137 patients were identified as being in need of care, only 11.5% of the sample requested such support. (2) 63.7% of patients chose the long version of the Hornheide Questionnaire.

CONCLUSIONS

In addition to their psychosocial burden, patients' desire for support should be assessed. Moreover, apart from screening tools, other ways to provide access to psychosocial care should be considered.

Risk factors for MRSA colonization in dermatologic patients in Germany

BACKGROUND AND OBJECTIVES

Detection of methicillin-resistant Staphylococcus aureus (MRSA) carriage requires well-defined risk factors (RFs). Except for "chronic wounds", RFs are mostly specified in national recommendations. To avoid ineffective and expensive screening, we divided the entity "wounds" into different categories and calculated further RFs in dermatologic patients.

PATIENTS AND METHODS

After a surveillance period with general MRSA screening, we correlated MRSA results with wound categories and dermatologically relevant diagnoses. We analyzed the screening efficacy by adding potential new RFs.

RESULTS

Ulcers (pressure, arterial, combined pressure/arterial ulcers, ulcers otherwise unclassified), type 2 diabetes mellitus (DM), and atopic dermatitis (AD) were significantly associated with MRSA carriage. Tumors (subgroup basal and squamous cell carcinoma) were also significantly associated with MRSA carriage but had a protective odds ratio. Differentiation of wound types did not provide added benefit. In all MRSA-positive patients with chronic wounds, other RKI-listed RFs or type 2 DM were found. Screening sensitivity was increased combining classic RFs (except wounds) with type 2 DM and AD.

CONCLUSIONS

In dermatologic patients, AD and type 2 DM were identified as new RFs. Distinct wound types were also found to be significant RFs, but differentiated screening offers no benefit. When screening patients according to national recommendations, excluding wounds but including type 2 DM and AD, there is no loss of sensitivity.

Viability of Lucilia sericata maggots after exposure to wound antiseptics

After debridement and before dressing a wound with maggots of calliphorid flies, one frequently performed step is the application of antiseptics to the prepared wound bed. However, the concomitant application of antiseptic agents during maggot therapy is regarded controversial as antiseptics may interfere with maggots' viability. In this experimental in vitro study, the viability of fly maggots was investigated after exposure to various antiseptics frequently used in wound care. Here, we show that Lucilia sericata fly maggots can survive up to an hour's exposure to wound antiseptics such as octenidine, povidone-iodine or polihexanide. Concomitant short-term application of wound antiseptics together with maggots on wound beds is tolerated by larvae and does not impair their viability.

Retrospektive Analyse von56 Weichteildefekten nach einzeitiger Rekonstruktion unter Verwendung von Dermisersatzpräparaten

HINTERGRUND

Der Verschluss von Wunden mit ausgeprägtem Weichteilschaden stellt eine chirurgische Herausforderung dar und erfordert häufig umfangreiche plastische Operationen sowie freie Lappenplastiken. Die Kombination von Dermisersatzpräparaten und Spalthauttransplantationen ist eine innovative Methode die zur Versorgung von komplexen Verletzungen der Extremitäten angewandt werden kann. Wir haben diese Technik in das Standard-Handwerkszeug bei komplexen Verletzungen der Extremitäten aufgenommen. Die klinischen Ergebnisse von 56 behandelten Patienten werden vorgestellt.

PATIENTEN UND METHODEN

In 44 Fällen (78,6 %) wurde die beschriebene Methode an Defekten der unteren Extremitäten verwendet, einschließlich sieben Personen (12,5 %), die sich einer Stumpfdeckung nach Amputation unterzogen. Zwölf Defekte (21,4 %) befanden sich an den oberen Extremitäten. In zwei Fällen (3,6 %) wurde die Matriderm(®) -Matrix verwendet, um Nerven von unmittelbar angrenzenden chirurgischen Implantaten zu schützen.

ERGEBNISSE

Bei 41 Patienten (73,2 %) kam es zur Einheilung des Transplantats ohne Komplikationen. Fünfzehn Patienten (26,8 %) zeigten eine gestörte Wundheilung nach Defektverschluss, die unter konservativer Therapie zur Ausheilung gebracht werden konnte. Ein Patient (1,8 %) zeigte ein Transplantatversagen, was eine Revisionsoperation erforderlich machte. Umfangreiche plastische Rekonstruktionen mussten bei keinem Patienten angewandt werden.

SCHLUSSFOLGERUNGEN

Bei Fällen, in denen ausgedehnte plastische Operationen nicht möglich oder nicht erwünscht sind, ist die Verwendung von Dermisersatzpräparaten in Kombination mit Spalthauttransplantationen eine vielversprechende Alternative zum Wundverschluss bei ausgedehnten Weichteilschäden.

[Importance of modern treatment procedures for infected and colonized wounds in dermatology]

In the coming years increasing numbers of patients with chronic ulcers and tumor wounds are to be expected, both of which are typically multifaceted diseases requiring complex and increasingly long-term ambulatory therapy. Therefore, in recent years special medical emphasis has been placed on efficacious therapies with good tolerability and also suitability regarding feasibility for outpatient treatment. Some of these methods, such as cold plasma therapy, extracorporeal shock wave therapy (ESWT), water-filtered infrared therapy (wIRA), electrostimulation (ES) and low level laser therapy (LLLT) have a good chance of success when applied as an adjuvant method in the multimodal treatment concept for patients with recalcitrant wounds. All of these methods have at least indirect antimicrobial properties which can be advantageous in cases of microbial infiltration of wounds. As for all other methods for treating recalcitrant wounds, the promising application of the aforementioned methods requires great expertise in wound healing together with a broad and continuous interdisciplinary diagnostics and therapy (wound center).

On the history of plasma treatment and comparison of microbiostatic efficacy of a historical high-frequency plasma device with two modern devices

Background: Cold atmospheric pressure plasma (CAP) with its many bioactive properties has defined a new medical field: the plasma medicine. However, in the related form of high-frequency therapy, CAP was even used briefly a century ago. The aim of this study was to review historic CAP treatments and to obtain data regarding the antimicrobial efficacy of a historical high-frequency plasma device.

Methods: First, historic literature regarding the history of CAP treatment was evaluated, because in the modern literature no data were available. Second, the susceptibility of 5 different bacterial wound isolates, cultured on agar, to a historic plasma source (violet wand [VW]) and two modern devices (atmospheric pressure plasma jet [APPJ] and Dielectric Barrier Discharge [DBD]) was analyzed . The obtained inhibition areas (IA) were compared.

Results: First, the most convenient popular historical electromedical treatments produced a so-called effluvia by using glass electrodes, related to today’s CAP. Second, all three tested plasma sources showed complete eradication of all tested microbial strains in the treated area. The “historical” cold VW plasma showed antimicrobial effects similar to those of modern APPJ and DBD regarding the diameter of the IA.

Conclusion: Some retrograde evidence may be deducted from this, especially for treatment of infectious diseases with historical plasma devices. The underlying technology may serve as model for construction of modern sucessive devices.

Maggots as potential vector for pathogen transmission and consequences for infection control in waste management

BACKGROUND AND AIMS

Debridement therapy with sterile bred larvae in non-healing wounds is a widely accepted safe and efficient treatment modality. However, during application in the contaminated wound bed microbial contamination with potential microbial pathogen spread after escape from the wound or after unreliable disposal procedure may happen, particularly in the case of not using bio-bags. The aims of this work were first to investigate the release of ingested bacteria into the environment by maggots and second to examine the common practice of freezing the maggots after use and/or disposal in trash-bags. Potential methods for hygienic safe disposal of used maggots should be deduced.

METHODS

First, Maggots were contaminated with S. aureus by allowing them to crawl over an agar surface completely covered with bacterial growth over 24 h at 37°C. After external disinfection maggots were transferred onto sterile Columbia agar plates and shedding of S. aureus was visualized. Second, maggots were frozen at -20°C for 1, 2, 5, 10, 30, and 60 min. After exposure, the larvae were transferred onto Columbia blood agar with consecutive incubation at 37°C over 48 h. The larvae were analyzed visually for mobility and eating activities. The frozen bodies of dead larvae were examined for viable bacteria.

RESULTS

We could demonstrate that maggots release formerly ingested pathogens (S. aureus). Freezing at -20°C for at least 60 min was able to kill all maggots, however the contaminant bacteria inside could survive.

CONCLUSION

Since freezing is apparently able to kill maggots but not to reliabely inactivate the ingested bacterial pathogens, we recommend the disposal of free-range larvae in screw cap vials after use to achieve full hygienic control.

Antimicrobial Efficacy of a Historical High-Frequency Plasma Apparatus in Comparison With 2 Modern, Cold Atmospheric Pressure Plasma Devices

BACKGROUND

Today, highly sophisticated devices deliver cold atmospheric pressure plasma (CAPP) with a multitude of bioactive properties, opening the window to a new medical field: plasma medicine. Different techniques to create the optimal plasma device for different medical indications are currently being explored. However, even a 100 years ago, CAPP was briefly used in the related form of high-frequency therapy. The objective of our study was to compare historic with modern techniques regarding antimicrobial efficacy.

METHODS

First, 26 different clinical isolates of relevant wound pathogens were treated in vitro with a historic violet wand (VW) and 2 modern plasma sources (kINPen 09 and dielectric barrier discharge [DBD]) and the obtained inhibition areas (IAs) were compared. Second, a biofilm model was used to compare biofilm inactivation by VW, DBD, ethanol, and polyhexanide treatment.

RESULTS

DBD with the largest electrode produced the largest IAs. VW showed results similar to 2 different modes of the kINPen 09. IAs of VW were enlargeable by attaching a larger electrode. Against biofilms, VW was less effective than DBD but more effective than ethanol 70% and polyhexanide.

CONCLUSION

The proven antimicrobial efficacy of VW may encourage the development of new, potent plasma devices based on the very simple and inexpensive technique of the historic high-frequency apparatus.

Skin and wound decontamination of multidrug-resistant bacteria by cold atmospheric plasma coagulation

BACKGROUND AND OBJECTIVES

Novel concepts to limit the spread of multidrug-resistant bacteria (MDR) are urgently needed. Since treatment with cold atmospheric plasma (CAP) has shown significant antibacterial properties, the purpose of this study was to evaluate the ability of CAP to eliminate MDR- compared to non-MDR-pathogens in chronic wounds.

METHODS

Eleven patients with 18 heavily colonized wounds were treated with a CE-certified commercial argon-based CAP source for 10 s/cm(2) in one session. The antimicrobial efficacy was assessed by calculating the microbial load before and after treatment.

RESULTS

A single CAP treatment reduced MDR in all wounds. In 14 treatments (63.6 %) and for 16 pathogens (66.7 %), a 100 % reduction of the bacterial load was observed. For 11 of 17 (64.7 %) MDR-pathogens and for 5 of 7 (71.4 %) other non-MDR-pathogens, complete eradication was achieved. The remaining 8 treatments showed reductions of 77.5 ± 18.6 % and the remaining pathogens a reduction of 74.8 ± 25.7 %.

CONCLUSIONS

As proof of principle, argon-based CAP serves as a potent treatment modality that was shown to limit MDR microbial colonization. The possible role of CAP in clinical MDR decontamination must be evaluated in clinical trials with repeated plasma treatment embedded in a comprehensive hygienic decontamination concept.

Filtration effects of zebra mussels on pathogens and total bacterial burden in the Odra Lagoon (South Baltic)

As a result of their mode of filter feeding, zebra mussels (Dreissena polymorpha Pall.) have been observed to purify natural water bodies and in vitro. Therefore, the possibility of using zebra mussels for water purification was investigated in a slightly brackish water body of a large lagoon. In this study, water samples were taken above, near and at distance from zebra mussel beds (MB) in the Odra Lagoon in North East Germany. Near typical bacterial species like Aeromonas spp. pathogenic bacteria with potential relation to hospital wastewater pollution (Burkholderia cepacia, Staphylococcus aureus, Weeksella spp.) were detected. There were no correlations found between either total bacteria or pathogens and distance to MB and no antimicrobial effect of the mussels could be deduced. For bioremediation in larger water bodies like lagoons, natural zebra MB do not seem to play a major antimicrobial role and the effect of artificial mussel grids especially against hospital pathogens should be investigated.