Laser-induced bubbles in living cells

Background and Objectives: Laser-activated micro- and nano-bubbles (LAB) in cells may be used as universal and sensitive non-toxic probes for measuring functional properties of individual cells. Study Design/Materials and Methods: Such bubbles can be detected and imaged by microscopy and flow cytometry. LABs in living blood and tumor cells were induced by pulsed (532 nm, 10 nanoseconds) laser radiation and detected by the thermal lens optical method. Results: Registered lifetime and maximal diameter of the studied LABs varied within the ranges of 0.02-10 microseconds and 0.44-100 mu m, respectively. LAB parameters, thresholds and probabilities, were found to depend upon the physiological state of cells. Specificity and sensitivity of LAB cytometry were increased due to the use of light-absorbing nanoparticles conjugated to specific monoclonal antibodies. Conclusions: LAB were found to be the universal phenomena that can be used for sensitive and non-invasive monitoring of any individual cell, intact or nanoparticle-treated.