Background: Current therapies for bone cancers - either primary or metastatic – are difficult to implement and
unfortunately not completely effective. An alternative therapy could be found in cold plasmas generated at
atmospheric pressure which have already demonstrated selective anti-tumor action in a number of carcinomas
and in more relatively rare brain tumors. However, its effects on bone cancer are still unknown.
Methods: Herein, we employed an atmospheric pressure plasma jet (APPJ) to validate its selectivity towards
osteosarcoma cell line vs. osteoblasts & human mesenchymal stem cells.
Results: Cytotoxicity following direct interaction of APPJ with cells is comparable to indirect interaction when
only liquid medium is treated and subsequently added to the cells, especially on the long-term (72 h of cell
culture). Moreover, following contact of the APPJ treated medium with cells, delayed effects are observed which
lead to 100% bone cancer cell death through apoptosis (decreased cell viability with incubation time in contact
with APPJ treated medium from 24 h to 72 h), while healthy cells remain fully viable and unaffected by the
Conclusions: The high efficiency of the indirect treatment indicates that an important role is played by the
reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the gaseous plasma stage and then
transmitted to the liquid phase, which overall lead to lethal and selective action towards osteosarcoma cells.
These findings open new pathways for treatment of metastatic bone disease with a minimally invasive approach.