Hollow Optical Fiber-Based Microplasma for Single Cell-Level Cancer Therapy

While atmospheric pressure plasmas have been used in cancer therapies the size of the delivery systems precludes single cell treatments. Here, a highly flexible hollow-core optical fiber-based microplasma device is shown to treat individual tumor cells. It is observed that the microplasma not only induced apoptosis in cultured murine cells in a dose-dependent manner, but also, in some experimental conditions, selectively destroyed cultured tumor cells with no harm to cultured fibroblasts as indicated by an Annex V apoptosis assay. The induction of apoptosis in cultured murine tumor cells is confirmed further using an in situ apoptosis assay, which also showed a well-defined boundary between plasma-treated and non-treated areas. This work enables new directed cancer therapies based on highly flexible and precise hollow optical fiber-based plasma medicine and offers a unique path to understanding plasma-induced tumor cell apoptosis.