Plasma Membrane Integrity and Survival of Melanoma Cells After Nanosecond Laser Pulses

Circulating tumor cells (CTCs) photoacoustic detection systems can aid clinical decision-making in the treatment of cancer. Interaction of melanin within melanoma cells with nanosecond laser pulses generates photoacoustic waves that make its detection possible. This study aims at: (1) determining melanoma cell survival after laser pulses of 6 ns at λ = 355 and 532 nm; (2) comparing the potential enhancement in the photoacoustic signal using λ = 355 nm in contrast with λ = 532 nm; (3) determining the critical laser fluence at which melanin begins to leak out from melanoma cells; and (4) developing a time-resolved imaging (TRI) system to study the intracellular interactions and their effect on the plasma membrane integrity. Monolayers of melanoma cells were grown on tissue culture-treated clusters and irradiated with up to 1.0 J/cm2. Surviving cells were stained with trypan blue and counted using a hemacytometer. The phosphate buffered saline absorbance was measured with a nanodrop spectrophotometer to detect melanin leakage from the melanoma cells post-laser irradiation. Photoacoustic signal magnitude was studied at both wavelengths using piezoelectric sensors. TRI with 6 ns resolution was used to image plasma membrane damage. Cell survival decreased proportionally with increasing laser fluence for both wavelengths, although the decrease is more pronounced for 355 nm radiation than for 532 nm. It was found that melanin leaks from cells equally for both wavelengths. No significant difference in photoacoustic signal was found between wavelengths. TRI showed clear damage to plasma membrane due to laser-induced bubble formation

Ultrathin Gold Nanowire-Functionalized Carbon Nanotubes for Hybrid Molecular Sensing

Carbon nanotubes (CNTs) have shown great potential as sensing component in the electrochemical, field effect transistor and optical sensors, because of their extraordinary onedimensional electronic structure, thermal conductivity, tunable and stable near-infrared emission. However, the insolubility of CNTs due to strong van der Waals interactions limits their use in the field of nanotechnology. In this study, we demonstrate that non-covalent ultrathin gold nanowires functionalized multi-walled carbon nanotube (GNW-CNT) hybrid sensing agents show highly efficient and selective immune molecular sensing in electrochemical and near-infrared photoacoustic imaging methods. A detection limit of 0.01 ng/mL for the Alpha-Fetoprotein (AFP) antigen with high selectivity is shown. The extraordinary optical absorption, thermal and electric conductivity of hybrid GNW-CNTs presented in this study could be an effective tactic to integrate imaging, sensing and treatment functionalities

Optoacoustic Measurements for Small-Volume Liquid Samples

High sensitivity of optoacoustic measurement method makes it possible to use it for the analysis of the liquid samples having microliter volume. The core of any measurement optoacoustic system is represented by a so-called optoacoustic cell. The paper deals with a layered prism optoacoustic cell. It is well-suited for the small-volume sample analysis. In the paper, laser-induced elastic pulse in the layered prism cell is examined at the stage of its generation, at the stage of its propagation through the body of the cell, and at the stage of the wideband pick-up with the piezoelectric transducer. This pulse serves to determine trace concentrations of various impurities in the sample. The optimization of layered prism cell parameters is proposed. Figures of merit of optoacoustic determination of lipopolysaccharides in the liquid small-volume sample with the use of the optimized layered prism cell are evaluated as an example

Technological Leapfrogging: Theory and International ICT Practices

A technological leapfrogging is a discrete stage in the development of a country or industry, representing the replacement of the previous technology with a fundamentally new one. The concept of technological leapfrogging has been developing since the mid 1980s, but still there is no generally accepted definition. The interest in the conditions and structure of technological leaps grew when it became clear that lagging countries and industries could develop rapidly by continuous imitation and innovation, jumping over obsolete technologies and avoiding investment in previous technological generations.The article relies on theoretical studies of leapfrogging and international experience in the development of information and communication technologies (ICT) for analysis of the conditions necessary for technological leaps. The ICT play a recognized role in economic growth and social development. Today, the catching-up countries have ambitious plans for ICT development, including next-generation fixed communications networks, 5G standard, e-commerce services and e-government.Based on the analysis of global experience, we define conditions for a successful technological leapfrogging in Russia and discuss the potential for its implementation. In the conditions of sanctions, it is important not just to reverse-engineer, but to make a technological leap in order to ensure technological self-sufficiency. Russia has partially created conditions for 5G technological leapfrogging by accumulating adaptation potential in terms of technology, equipment and personnel; developing science-industry cooperation; and creating conditions for favorable socio-technological climate