In vitro biological effects induced by ultrasounds-cell interaction

Over the last few years, low intensity ultrasounds (US) have been widely used as therapeutic tool The widespread use of US in different application fields drove researchers to study the related bioeffects the more significant range from membrane poration (sonoporation) to the triggering of cytotoxic and inflammatory processes. Currently, an univocal experimental methodology accepted to investigate and quantitatively describe the biological risk with proper indicators is still lacking. As well known, the primary function of skin is to protect the body to potentially harmful external substances an microorganisms 3 Keratinocytes comprise primarily the epidermis and with their tight junctions form a barrier between the host and the environment 3 4 For this reason, keratinocytes directly interact with non invasive medical treatments US In this regard, firstly we developed experimental setup to define the in vitro effects of very low intensity 0 5 and 1 MHz US in immortalized human keratinocytes HaCaT and human melanoma SK MEL 28 cells By confocal fluorescence microscopy we pointed out, for the first time even in the subcavitation regime, relevant modifications in the membrane morphology and functionality. In this framework, we investigated the possible activation of inflammatory pathways, cytokine interleukine 6 (IL 6 inducible nitric oxide synthase iNOS and Nuclear Factor κ B NF kB) activation In addition, cell proliferation was evaluated by means of the MTT proliferation assay and by flow cytometry to detect apoptotic cells (sub G 1 DNA content)