Investigation of Microbubble Cavitation-Induced Calcein Release from Cells In Vitro.

In the present study, microbubble (MB) cavitation signal analysis was performed together with calcein release evaluation in both pressure and exposure duration domains of the acoustic field. A passive cavitation detection system was used to simultaneously measure MB scattering and attenuation signals for subsequent extraction efficiency relative to MB cavitation activity. The results indicate that the decrease in the efficiency of extraction of calcein molecules from Chinese hamster ovary cells, as well as cell viability, is associated with MB cavitation activity and can be accurately predicted using inertial cavitation doses up to 0.18 V × s (R2 > 0.9, p < 0.0001). No decrease in additional calcein release or cell viability was observed after complete MB sonodestruction was achieved. This indicates that the optimal exposure duration within which maximal sono-extraction efficiency is obtained coincides with the time necessary to achieve complete MB destruction. These results illustrate the importance of MB inertial cavitation in the sono-extraction process. To our knowledge, this study is the first to (i) investigate small molecule extraction from cells via sonoporation and (ii) relate the extraction process to the quantitative characteristics of MB cavitation acoustic spectra.

[Histological analysis of electrochemotherapy influence in Lewis lung carcinoma]. / Epidermoidines plauciu karcinomos elektrochemoterapinio poveikio histologinis tyrimas.

Under the influence of strong electric fields the permeability of tumor cell membranes to poor permeating drugs increases and as a result the tumor growth is inhibited. This new tumor treatment method is named electrochemotherapy. We investigated the electrochemotherapy influence of bleomycin upon mice Lewis Lung Carcinoma by using optical histological and electron microscopic tumor analysis. It was shown that due to electrochemotherapy tumor necrosis area is significantly increased, intercellular gaps enlarge, and a big amount of cells is destroyed. Cell and nucleus membranes break as well as hemorrhage are very often. The observable histological tumor change was noted when electrical pulses of 1300 V/cm and 0.1 ms duration were applied. Pulses of 1700 V/cm and 0.1 ms duration induce total tumor destruction.