Biological effects of laser-induced shock waves: structural and functional cell damage in vitro

A new experimental design has been used to study the biological effects of laser-induced shock waves which minimizes or eliminates interference from ancillary effects such as bubble formation, ultraviolet (UV) radiation, or formation of radicals. The effects of these shock waves on human lymphocytes and red blood cells have been investigated. Three assays were used to determine cell injury: electron microscopy, ethidium bromide/fluorescein diacetate (EB/FDA) staining and incorporation of tritiated thymidine. The degree of cell damage was related to the pressure and the number of pulses. Cell damage was quantified and correlated using the three assays. Measurements of gross structural alterations as determined by transmission electron microscopy were less sensitive than assays of structural damage (e.g., EB/FDA assay) which were less sensitive than functional assays (e.g., incorporation of tritiated thymidine).