  Efficient and biologically safe mode of cold atmospheric plasma jet (CAPJ) is
crucial for the development of CAPJ-based anticancer therapy. In the experiment
and numerical simulations, by changing the pulse duration of a positive-pulsed
voltage, we found the optimal CAPJ mode with regular streamer propagation. CAPJ
regimes with a maximum discharge current at a temperature T<42 C substantially
suppressed the viability of cancer cells. To enhance cell killing, gold
nanoparticles (NPs) were added to the cells before and after the CAPJ exposure.
Combination of CAPJ, generated with positive pulsed voltage, and gold
nanoparticles decreased viability of NCI-H23 epithelial-like lung
adenocarcinoma, A549 lung adenocarcinoma, BrCCh4e-134 breast adenocarcinoma and
uMel1 uveal melanoma cells. Polyethylene glycol-modified nanoparticles with
attached fluorescent label were used to visualize the uptake of NPs. We
demonstrated that NPs efficiently entered the cells when were added to the
cells just before CAPJ exposure or up to two hours afterwards. The efficiency
ofNPs penetration into cells positively correlated with the induced cytotoxic
effect: it was maximal when NPs was added to cells right before or immediately
after CAPJ exposure. Summarizing, the treatment with optimal CAPJ modes in
combination with modified NPs, bearing the cancer-addressed molecules and
therapeutics may be next strategy of strengthening the CAPJ-based antitumor
approaches.
