Research ArticleExperimental Studies

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

DENIS GÜMBEL, BETTINA SUCHY, LASSE WIEN, NADINE GELBRICH, MATTHIAS NAPP, AXEL KRAMER, AXEL EKKERNKAMP, GEORG DAESCHLEIN and MATTHIAS B. STOPE
Anticancer Research October 2017, 37 (10) 5407-5414;

Abstract

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.

Osteosarcoma (OS), the most common primary malignant bone tumor in adolescents and young adults, is known to be highly aggressive and cause progressive bone destruction (1). Current OS treatment contains neoadjuvant multiagent chemotherapy regimens including doxorubicin, cisplatin, cyclophosphamide, ifosfamide and methotrexate (2). Subsequent complete surgical resection of the tumor is usually followed by postoperative, adjuvant chemotherapy (3). Although it occurs most frequently in the metaphyses of long bones, tumor localization in the pelvis, spine or skull may be challenging due to adjacent neurovascular structures. To date, despite a very limited number of active agents, a 5-year survival rate of up to 60-70% in non-metastatic disease has been achieved (4). However, limited treatment options especially in chemo-resistant or advanced cases and relapse have led to a stagnation in progress of systemic OS management for the last decades (5). The heterogeneous nature of OS further complicates treatment.

Cold atmospheric plasma (CAP), a highly reactive (partially) ionized physical state containing a dose controlled mixture of biologically-active agents has been shown to exert anticancer effects in vitro and in vivo (6-9). These active agents, generated by focused electrical discharge, include positive and negative ions, electrons, excited atoms and molecules, free radicals such as singlet oxygen, superoxide, reactive oxygen and nitrogen species (ROS and RNS), photons and electromagnetic radiation (10-12). Active plasma components can be adjusted through carrier gas composition (mostly argon and helium), gas flow, and electrical voltage and depends on environmental conditions, e.g. temperature and humidity (13, 14). The method of action is not completely understood. Tumor cell proliferation is attenuated by apoptotic cell death rather than by direct cytotoxic effects (15-20). In a balanced cell state, ROS are produced as a by-product of metabolic processes controlled with antioxidants. Prooxidant therapies are based on the rationale that a further oxidative stimulus produces oxidative stress in tumor cells, which cause the collapse of the antioxidant systems, leading to cell death (21). The mixture of ROS, RNS and their metabolites leads to an interaction with membrane structures producing oxidative stress in tumor cells (11). The tumor cell responses to these oxidative stimuli finally seem to result in apoptosis due to immature redox resistance (22). The anti-tumor efficacy may be triggered by the interaction of highly reactive H2O2 directly generated by CAP as well as possibly more importantly by an induction of intracellular generation of H2O2 by CAP, since H2O2 serves as an important signalling molecule in cancer cells (23, 24).

View this table:
Table I.

Characteristics of the cold atmospheric plasma devices.

The purpose of this study was to evaluate the therapeutic potential of different commercially available and medically accredited CAP devices in the treatment of osteosarcoma.

Materials and Methods

Cell culture. Cells of the OS cell line U2-OS (purchased from the American Type Culture Collection, Manassas, VA, USA) were propagated in DMEM medium containing 1.0 g/l glucose supplemented with 10% fetal bovine serum, 1 mM sodium pyruvate, and 1% penicillin/streptomycin (all from PAN Biotech, Aidenbach, Germany) in a humidified atmosphere at 5% CO2 and 37°C. 3-T-3 fibroblasts were propagated in DMEM medium containing 4.5 g/l glucose supplemented with 10% fetal bovine serum, 1 mM sodium pyruvate, and 1% penicillin/streptomycin (all from PAN Biotech, Aidenbach, Germany) in a humidified atmosphere at 5% CO2 and 37°C. A total of 4×106 U2-OS cells or 2×106 3-T-3 cells were seeded on an uncoated cell culture plate. After 4 days cells were washed twice in phosphate buffered saline and detached using 0,1% trypsin/0,04% ethylendiaminetetraacetic acid (EDTA) prior to resuspension in DMEM medium.

CAP treatment. For comparative analysis of CAP treatment three different plasma sources were used: The following atmospheric pressure plasma jets (APPJ) were used for the experiments: Maxium® (KLS Martin, Tuttlingen, Germany) using the following settings: Carrier gas: Argon, gas flow: 2.6 l/min, 25W.

Cold Plasma Coagulator 1000 (Söring GmbH, Quickborn, Germany) using the following settings: Carrier gas: Helium, gas flow: 2.6 l/min; 25 W

kINPen MED (Neoplas Tools, Greifswald, Germany) using the following settings: Carrier gas: Argon, gas flow: 4 l/min; pulsed plasma (2.5 kHz), supply voltage=65 V DC; frequency: 1.0 MHz.

Settings of the plasma sources used are summarized in Table I.

A total of 4.0×104 (U2-OS) and 2.0×104 (3-T-3) cells were treated for 5s, 10s and 30s in suspension in a standardized, meandering pattern. Cells were immediately transferred to poly-L-lysine (PAN Biotech) coated 24-well cell culture plates after CAP treatment and incubated in DMEM medium for the indicated time period.

Cell proliferation assay. Cell proliferation was examined by determining viable cell count of U2-OS and 3-T-3 cells using a CASY Cell Counter and Analyzer Model TT (Roche Applied Science, Mannheim, Germany). After detachment at 4 h, 24 h, 48 h, 72h, 96h and 120h by trypsin/EDTA treatment cells were suspended in CASYton (Roche Applied Science). Three replicates of 400 μl cell suspension were analysed in a 1:100 dilution. Measurements were performed using a capillary of 150 μm in diameter. The following cell line specific gate settings were utilized to discriminate between viable, dead cells, and cellular debris: 7.20 μm/13.95 μm (U2-OS), 5.25 μm/8.22 μm (3-T-3). Results are demonstrated as mean±SD of at least three independent experiments for each device and application time.

Statistical analysis. Statistical analysis was performed using GraphPad Prism 5.0 software (GraphPad Software, La Jolla, CA, USA). Significant differences between two groups were determined using the unpaired Student's t-test. p-Values of p≤0.05 (*), p≤0.01 (**), and p≤0.001 (***) were considered statistically significant. Data in the figures are shown as mean±SD of at least three independent experiments.

Results

Antiproliferative efficacy of Maxium®. Over a period of 120 h, argon treated U2-OS cells (controls) exhibited characteristic cell growth. In contrast, CAP treated U2-OS cells showed significantly attenuated cell proliferation 120 h after treatment depending on application time. While 120 h after CAP treatment over 5 sec viable cell count was 6.5×105±4.3×104 compared to 7.7×105±3.6×104 (15% reduction), 10 sec of treatment led to a reduced cell count by 53% (3.5×105±9.4×104 compared to 7.4×105±8.0×104 p≤0.01 (Figure 1A and B). An 84% reduction was observed 120 h after CAP treatment over 30s (9.8×104±8.4×104 compared to 6.2×105±7.0×104 p≤0.01) (Figure 1C).

Figure 1.
Figure 1.

Cell proliferation of U2-OS in an OS in vitro cell culture model. Viable cell counts of U2-OS cells after CAP treatment using Maxium® (KLS Martin) over 5 sec (A), 10s (B) and 30 sec (C). Data are given as the mean±SD of cell count. *p≤0.05; **p≤0.01 and ***p≤0.001 vs. control, as determined by Student's t-test.

Figure 2.
Figure 2.

Cell proliferation of U2-OS in an OS in vitro cell culture model. Viable cell counts of U2-OS cells after CAP treatment using Cold Plasma Coagulator 1000 (Söring GmbH) over 5 sec (A), 10 sec (B) and 30s (C). Data are given as the mean±SD of cell count. *p≤0.05; **p≤0.01 and ***p≤0.001 vs. control, as determined by Student's t-test.

Figure 3.
Figure 3.

Cell proliferation of U2-OS in an OS in vitro cell culture model. Viable cell counts of U2-OS cells after CAP treatment using kINPen MED (Neoplas tools) over 5 sec (A), 10 sec (B) and 30 sec (C). Data are given as the mean±SD of cell count. *p≤0.05; **p≤0.01 and ***p≤0.001 vs. control, as determined by Student's t-test.

Figure 4.
Figure 4.

Cell proliferation of 3T3 fibroblasts in an OS in vitro cell culture model. Viable cell counts of 3T3 fibroblast cells after CAP treatment using Maxium® (KLS Martin) over 5 sec (A), 10 sec (B) and 30 sec (C). Data are given as the mean±SD of cell count. *p≤0.05; **p≤0.01 and ***p≤0.001 vs. control, as determined by Student's t-test.

Figure 5.
Figure 5.

Cell proliferation of 3T3 fibroblasts in an OS in vitro cell culture model. Viable cell counts of 3T3 fibroblast cells after CAP treatment using Cold Plasma Coagulator 1000 (Söring GmbH) over 5 sec (A), 10 sec (B) and 30 sec (C). Data are given as the mean±SD of cell count. *p≤0.05; **p≤0.01 and ***p≤0.001 vs. control, as determined by Student's t-test.

Figure 6.
Figure 6.

Cell proliferation of 3T3 fibroblasts in an OS in vitro cell culture model. Viable cell counts of 3T3 fibroblast cells after CAP treatment using kINPen MED (Neoplas tools) over 5 sec (A), 10 sec (B) and 30 sec (C). Data are given as the mean±SD of cell count. *p≤0.05; **p≤0.01 and ***p≤0.001 vs. control, as determined by Student's t-test.

In parallel, 3-T-3-fibroblast cells showed characteristic cell growth after argon control treatment. Following CAP treatment over 5 sec, cell count after 120 h of incubation was 9.4×105±2.7×104 compared to 1.1×106±8.1×104, thus resulted in a 17% reduction. 10 sec of CAP treatment resulted in a 51% reduced cell number (3.5×105±9.4×104 compared to 7.4×105±8.0×104 p≤0.01), while 30 sec led to an 81% decrease in cell number (9.8×104±8.4×104 compared to 6.2×105±7.0×104 p≤0.01) (Figure 2A-C).

Antiproliferative efficacy of Cold Plasma Coagulator 1000. Helium treated U2-OS cells (controls) exhibited characteristic cell growth. Cell proliferation was significantly altered following CAP treatment of U2-OS cells depending on application time. Following CAP treatment over 5 sec viable cell count was 1.5×105±1.6×105 compared to 6.7×105±4.4×104 p≤0.01 (78% reduction) after 120 h of incubation (Figure 3 A). 10s of treatment led to a reduced cell count by 74% (3.5×105±9.4×104 compared to 7.4×105±8.0×104 p≤0.05 and 90% reduction was observed 120h after CAP treatment over 30s (4.4×103±5.0×104 compared to 4.3×105±1.5×105 p≤0.01) (Figure 3B and C).

In parallel, 3-T-3-fibroblast cells showed characteristic cell growth following helium control treatment. Following CAP treatment over 5 sec cell count after 120 h of incubation was 2.0×105±1.9×105 compared to 8.9×105±2.1×105 p≤0.01 which corresponds to a reduction of 77%. 10s of CAP treatment resulted in an 82% reduced cell number (1.3×105±9.0×104 compared to 7.4×105±2.7×105 p≤0.01) while 30 sec led to a 98% decrease in cell number (1.4×104±8.9×103 compared to 7.5×105±6.2×104 p≤0.001) (Figure 4 A-C).

Antiproliferative efficacy of kINPen MED. Argon treated U2-OS cells (controls) exhibited characteristic cell growth. Cell proliferation was significantly altered following CAP treatment of U2-OS cells depending on application time. After 120 h of incubation following CAP treatment over 5 sec viable cell count was diminished by 7% (9.2×105±1.7×104 compared to 9.9×105±2.0×104 p≤0.05) (Figure 5A). 10s of treatment led to a reduced cell count by 40% (6.6×105±3.0×104 compared to 1.1×106±6.4×104 p≤0.05 and 72% reduction was observed 120 h after CAP treatment over 30s (2.5×105±4.6×104 compared to 9.0×105±8.4×104 p≤0.001) (Figure 5B and C).

In parallel, 3-T-3-fibroblast cells showed characteristic cell growth following argon control treatment. Following CAP treatment over 5 sec cell count after 120 h of incubation was 5.4×105±6.4×104 compared to 7.2×105±2.6×104 p≤0.01 which corresponds to a reduction of 24%. 10 sec of CAP treatment resulted in a by 57% reduced cell number (3.5×105±6.3×104 compared to 8.2×105±6.1×104 p≤0.001) while 30 sec led to a 72% decrease in cell number (1.9×104±4.2×104 compared to 7.0×105±2.8×104 p≤0.001) (Figure 6A-C).

Discussion

CAP has been shown to exert antitumor effects in a variety of cancer entities including prostate, pancreatic, head and neck squamous cell carcinoma, melanoma, myeloma and osteosarcoma (7, 15, 16, 25-28). Here, CAP effects on tumor cell proliferation involved the induction of apoptosis rather than direct cytotoxic effects (29). More recently, a potential involvement of reactive species like ROS and RNS leading to DNA damage, lipid peroxidation or mitochondrial dysfunction has been reported as active agents in oncotherapy (30). Both, reactive species composition as well as the pattern of these species, is primarily determined by the used CAP device (31). Beside environmental conditions constructional and physical properties of the plasma devices are responsible for physical CAP characteristics and thus for biological efficacy. Device-dependent effects of different plasma sources on cells, however, remain elusive.

In the study presented, epithelial osteosarcoma cells (U2-OS) and non-malignant fibroblasts (3-T-3) were applied as cellular model system to assess anti-cancer efficacy of three approved CAP devices in Europe. The Cold Plasma Coagulator 1000, the Maxium® and the kINPen MED, are plasma jets. Within this setup, CAP is generated by high voltage applied between two electrodes. In medical approaches, human skin or tissue represents one of them. The design principle is based on two inbuilt electrodes with a direct evacuation of the target structure by a non-oxygen carrier gas (argon/helium). The originally low concentration of CAP compounds compared to DBD devices is effectively compensated by bundling of the gas flow and results in high concentrations of reactive species (32).

As expected, our data showed both a cell type-specific as well as a treatment time-dependent effect on epithelial and fibroblastic cell proliferation. Applying Maxium® and Cold Plasma Coagulator, epithelial U2-OS cells appeared more sensitive to CAP treatment than 3-T-3 fibroblasts depending on treatment time. A single kINPen Med treatment of over 30 sec on epithelial U2-OS cells tended to a stronger attenuation of cell growth compared to fibroblastic 3-T-3 cells.

Furthermore, comparable experiments applying epithelial prostate cancer cells to a kINPen MED device demonstrated a stronger anti-proliferative effect on epithelial prostate cancer cells than to epithelial U2-OS cells (16), emphasizing cell type-specific CAP efficacy.

Furthermore, the anti-proliferative cell response increased with increasing times of CAP treatment for all three devices. CAP treatment represents a single, short-time application of CAP and thus treatment time corresponds to drug concentration and dose response of chemical compounds in conventional chemotherapy. Due to the physical state of CAP and due to the dependency on different environmental variables during CAP generation, it is currently not feasible to define a parameter corresponding to the ‘CAP concentration’. Consequently, examination of the biological impact is the only strategy to specify CAP's biological efficacy.

Besides cell type and treatment time, the CAP impact on cellular growth strongly depended on the CAP device utilized in the experiments. On the other hand, the individual biological impact of CAP devices should be examined and considered in every single case of medical approach.

In summary, CAP treatment using quite different plasma sources and application times individually attenuates cell proliferation of OS and fibroblast cells in a dose-dependent manner, whereby tumor cells tend to be more susceptible to CAP therefore making it a promising new treatment option. Further studies, however, should examine the effects of CAP treatment on more complex malignant tissues evaluating effects on tumor microenvironment and penetration depth to determine optimal tumor specific application sources and dosage.

Footnotes

  • ↵* These Authors contributed equally to this study.

  • Conflicts of Interest

    None of the Authors stated a conflict of interest. No funding was received for the study.

  • Received August 13, 2017.
  • Revision received September 8, 2017.
  • Accepted September 11, 2017.

References

  1. ↵
    1. Stiller CA,
    2. Bielack SS,
    3. Jundt G,
    4. Steliarova-Foucher E
    : Bone tumours in european children and adolescents, 1978-1997. Report from the automated childhood cancer information system project. Eur J Cancer 42(13): 2124-2135, 2006.
    OpenUrlCrossRefPubMed
  2. ↵
    1. Osasan S,
    2. Zhang M,
    3. Shen F,
    4. Paul PJ,
    5. Persad S,
    6. Sergi C
    : Osteogenic sarcoma: A 21st century review. Anticancer Res 36(9): 4391-4398, 2016.
    OpenUrlAbstract/FREE Full Text
  3. ↵
    1. Luetke A,
    2. Meyers PA,
    3. Lewis I,
    4. Juergens H
    : Osteosarcoma treatment – where do we stand? A state of the art review. Cancer Treat Rev 40(4): 523-532, 2014.
    OpenUrlCrossRefPubMed
  4. ↵
    1. Allison DC,
    2. Carney SC,
    3. Ahlmann ER,
    4. Hendifar A,
    5. Chawla S,
    6. Fedenko A,
    7. Angeles C,
    8. Menendez LR
    : A meta-analysis of osteosarcoma outcomes in the modern medical era. Sarcoma 2012: 704872, 2012.
    OpenUrlPubMed
  5. ↵
    1. Chou AJ,
    2. Gorlick R
    : Chemotherapy resistance in osteosarcoma: Current challenges and future directions. Expert Rev Anticancer Ther 6(7): 1075-1085, 2006.
    OpenUrlCrossRefPubMed
  6. ↵
    1. Welz C,
    2. Emmert S,
    3. Canis M,
    4. Becker S,
    5. Baumeister P,
    6. Shimizu T,
    7. Morfill GE,
    8. Harreus U,
    9. Zimmermann JL
    : Cold atmospheric plasma: A promising complementary therapy for squamous head and neck cancer. PLoS One 10(11): e0141827, 2015.
    OpenUrl
  7. ↵
    1. Partecke LI,
    2. Evert K,
    3. Haugk J,
    4. Doering F,
    5. Normann L,
    6. Diedrich S,
    7. Weiss FU,
    8. Evert M,
    9. Huebner NO,
    10. Guenther C,
    11. Heidecke CD,
    12. Kramer A,
    13. Bussiahn R,
    14. Weltmann KD,
    15. Pati O,
    16. Bender C,
    17. von Bernstorff W
    : Tissue tolerable plasma (ttp) induces apoptosis in pancreatic cancer cells in vitro and in vivo. BMC Cancer 12: 473, 2012.
    OpenUrlCrossRefPubMed
    1. Babington P,
    2. Rajjoub K,
    3. Canady J,
    4. Siu A,
    5. Keidar M,
    6. Sherman JH
    : Use of cold atmospheric plasma in the treatment of cancer. Biointerphases 10(2): 029403, 2015.
    OpenUrl
  9. ↵
    1. Heslin C,
    2. B D,
    3. Milosavljevic V,
    4. Laycock M,
    5. Cullen P,
    6. Bourke P
    : Quantitative assessment of blood coagulation by cold atmospheric plasma. Plasma Medicine 4(1-4): 153-163, 2014.
    OpenUrl
  10. ↵
    1. Bekeschus S,
    2. Schmidt A,
    3. Bethge L,
    4. Masur K,
    5. von Woedtke T,
    6. Hasse S,
    7. Wende K
    : Redox stimulation of human thp-1 monocytes in response to cold physical plasma. Oxid Med Cell Longev 2016: 5910695, 2016.
    OpenUrl
  11. ↵
    1. Gumbel D,
    2. Gelbrich N,
    3. Napp M,
    4. Daeschlein G,
    5. Kramer A,
    6. Sckell A,
    7. Burchardt M,
    8. Ekkernkamp A,
    9. Stope MB
    : Peroxiredoxin expression of human osteosarcoma cells is influenced by cold atmospheric plasma treatment. Anticancer Res 37(3): 1031-1038, 2017.
    OpenUrlAbstract/FREE Full Text
  12. ↵
    1. Bekeschus S,
    2. Iséni S,
    3. Reuter S,
    4. Masur K,
    5. Weltmann KD
    : Nitrogen shielding of an argon plasma jet and its effects on human immune cells. IEEE Transactions on Plasma Science 43(3): 776-781, 2015.
    OpenUrl
  13. ↵
    1. Schmidt A,
    2. Bekeschus S,
    3. Jablonowski H,
    4. Barton A,
    5. Weltmann KD,
    6. Wende K
    : Role of ambient gas composition on cold physical plasma-elicited cell signaling in keratinocytes. Biophys J 112(11): 2397-2407, 2017.
    OpenUrl
  14. ↵
    1. Akhlaghi M,
    2. Rajayi H,
    3. Mashayekh AS,
    4. Khani M,
    5. Hassan ZM,
    6. Shokri B
    : On the design and characterization of a new cold atmospheric pressure plasma jet and its applications on cancer cells treatment. Biointerphases 10(2): 029510, 2015.
    OpenUrl
  15. ↵
    1. Weiss M,
    2. Gumbel D,
    3. Hanschmann EM,
    4. Mandelkow R,
    5. Gelbrich N,
    6. Zimmermann U,
    7. Walther R,
    8. Ekkernkamp A,
    9. Sckell A,
    10. Kramer A,
    11. Burchardt M,
    12. Lillig CH,
    13. Stope MB
    : Cold atmospheric plasma treatment induces anti-proliferative effects in prostate cancer cells by redox and apoptotic signaling pathways. PLoS One 10(7): e0130350, 2015.
    OpenUrlPubMed
  16. ↵
    1. Weiss M,
    2. Gumbel D,
    3. Gelbrich N,
    4. Brandenburg LO,
    5. Mandelkow R,
    6. Zimmermann U,
    7. Ziegler P,
    8. Burchardt M,
    9. Stope MB
    : Inhibition of cell growth of the prostate cancer cell model lncap by cold atmospheric plasma. In Vivo 29(5): 611-616, 2015.
    OpenUrlAbstract/FREE Full Text
    1. Wang M,
    2. Holmes B,
    3. Cheng X,
    4. Zhu W,
    5. Keidar M,
    6. Zhang LG
    : Cold atmospheric plasma for selectively ablating metastatic breast cancer cells. PLoS One 8(9): e73741, 2013.
    OpenUrl
    1. Arndt S,
    2. Landthaler M,
    3. Zimmermann JL,
    4. Unger P,
    5. Wacker E,
    6. Shimizu T,
    7. Li YF,
    8. Morfill GE,
    9. Bosserhoff AK,
    10. Karrer S
    : Effects of cold atmospheric plasma (cap) on ss-defensins, inflammatory cytokines, and apoptosis-related molecules in keratinocytes in vitro and in vivo. PLoS One 10(3): e0120041, 2015.
    OpenUrl
    1. Xu D,
    2. Luo X,
    3. Xu Y,
    4. Cui Q,
    5. Yang Y,
    6. Liu D,
    7. Chen H,
    8. Kong MG
    : The effects of cold atmospheric plasma on cell adhesion, differentiation, migration, apoptosis and drug sensitivity of multiple myeloma. Biochem Biophys Res Commun 473(4): 1125-1132, 2016.
    OpenUrl
  20. ↵
    1. Ahn HJ,
    2. Kim KI,
    3. Kim G,
    4. Moon E,
    5. Yang SS,
    6. Lee JS
    : Atmospheric-pressure plasma jet induces apoptosis involving mitochondria via generation of free radicals. PLoS One 6(11): e28154, 2011.
    OpenUrlPubMed
  21. ↵
    1. Lotfy K
    : Cold atmospheric plasma and oxidative stress: Reactive oxygen species vs. Antioxidant. Austin Biochem 1(1): 1001, 2016.
    OpenUrl
  22. ↵
    1. Xu D,
    2. Liu D,
    3. Wang B,
    4. Chen C,
    5. Chen Z,
    6. Li D,
    7. Yang Y,
    8. Chen H,
    9. Kong MG
    : In situ oh generation from o2- and h2o2 plays a critical role in plasma-induced cell death. PLoS One 10(6): e0128205, 2015.
    OpenUrl
  23. ↵
    1. Bekeschus S,
    2. Kolata J,
    3. Winterbourn C,
    4. Kramer A,
    5. Turner R,
    6. Weltmann KD,
    7. Broker B,
    8. Masur K
    : Hydrogen peroxide: A central player in physical plasma-induced oxidative stress in human blood cells. Free Radic Res 48(5): 542-549, 2014.
    OpenUrlCrossRefPubMed
  24. ↵
    1. Yan D,
    2. Cui H,
    3. Zhu W,
    4. Nourmohammadi N,
    5. Milberg J,
    6. Zhang LG,
    7. Sherman JH,
    8. Keidar M
    : The specific vulnerabilities of cancer cells to the cold atmospheric plasma-stimulated solutions. Sci Rep 7(1): 4479, 2017.
    OpenUrl
  25. ↵
    1. Kim JY,
    2. Ballato J,
    3. Foy P,
    4. Hawkins T,
    5. Wei Y,
    6. Li J,
    7. Kim SO
    : Apoptosis of lung carcinoma cells induced by a flexible optical fiber-based cold microplasma. Biosens Bioelectron 28(1): 333-338, 2011.
    OpenUrlPubMed
    1. Guerrero-Preston R,
    2. Ogawa T,
    3. Uemura M,
    4. Shumulinsky G,
    5. Valle BL,
    6. Pirini F,
    7. Ravi R,
    8. Sidransky D,
    9. Keidar M,
    10. Trink B
    : Cold atmospheric plasma treatment selectively targets head and neck squamous cell carcinoma cells. Int J Mol Med 34(4): 941-946, 2014.
    OpenUrl
    1. Schuster M,
    2. Seebauer C,
    3. Rutkowski R,
    4. Hauschild A,
    5. Podmelle F,
    6. Metelmann C,
    7. Metelmann B,
    8. von Woedtke T,
    9. Hasse S,
    10. Weltmann KD,
    11. Metelmann HR
    : Visible tumor surface response to physical plasma and apoptotic cell kill in head and neck cancer. J Craniomaxillofac Surg 44(9): 1445-1452, 2016.
    OpenUrl
  28. ↵
    1. Gumbel D,
    2. Gelbrich N,
    3. Weiss M,
    4. Napp M,
    5. Daeschlein G,
    6. Sckell A,
    7. Ender SA,
    8. Kramer A,
    9. Burchardt M,
    10. Ekkernkamp A,
    11. Stope MB
    : New treatment options for osteosarcoma – inactivation of osteosarcoma cells by cold atmospheric plasma. Anticancer Res 36(11): 5915-5922, 2016.
    OpenUrlAbstract/FREE Full Text
  29. ↵
    1. Kalghatgi S,
    2. Kelly CM,
    3. Cerchar E,
    4. Torabi B,
    5. Alekseev O,
    6. Fridman A,
    7. Friedman G,
    8. Azizkhan-Clifford J
    : Effects of non-thermal plasma on mammalian cells. PLoS One 6(1): e16270, 2011.
    OpenUrlCrossRefPubMed
  30. ↵
    1. Engel RH,
    2. Evens AM
    : Oxidative stress and apoptosis: A new treatment paradigm in cancer. Front Biosci 11: 300-312, 2006.
    OpenUrlCrossRefPubMed
  31. ↵
    1. Dünnbier M,
    2. Schmidt-Bleker A,
    3. Winter J,
    4. Wolfram M,
    5. Hippler R,
    6. Weltmann KD,
    7. Reuter S
    : Ambient air particle transport into the effluent of a cold atmospheric-pressure argon plasma jet investigated by molecular beam mass spectrometry. Journal of Physics D: Applied Physics 46(43): 435203, 2013.
    OpenUrl
  32. ↵
    1. Weiss M,
    2. Daeschlein G,
    3. Kramer A,
    4. Burchardt M,
    5. Brucker S,
    6. Wallwiener D,
    7. Stope MB
    : Virucide properties of cold atmospheric plasma for future clinical applications. J Med Virol 89(6): 952-959, 2017.
    OpenUrl
Back to top

In this issue

Print
Download PDF
Article Alerts
Email Article
Citation Tools
Reprints and Permissions
Comparison of Cold Atmospheric Plasma Devices' Efficacy on Osteosarcoma and Fibroblastic In Vitro Cell Models
DENIS GÜMBEL, BETTINA SUCHY, LASSE WIEN, NADINE GELBRICH, MATTHIAS NAPP, AXEL KRAMER, AXEL EKKERNKAMP, GEORG DAESCHLEIN, MATTHIAS B. STOPE
Anticancer Research Oct 2017, 37 (10) 5407-5414;
Reddit logo Twitter logo Facebook logo Mendeley logo

Jump to section

Keywords