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Purpose: Study of the influence of high-power pulses of coherent non-ionizing terahertz (THz) radiation on the formation of foci of double-strand DNA breaks and the proliferative activity of human neuronal cells. Material and methods: Irradiated cell cultures are direct reprogramming neural progenitor cells (drNPCs), neuroblastoma cells (SK-N-BE). Cells are irradiated with a sequence of THz radiation pulses with a peak intensity of ~ 20 GW/cm2 and electric field strength of 2.8 MV/cm. Irradiation lasts 30 mins. Results: There is no statistically significant difference in the number of γH2AX histone foci between experimental and control cell groups. Conclusion: It was shown that a short exposure (30 min) of cells to THz radiation with intensity of 20 GW/cm2 does not affect the proliferative activity of both neural progenitor cells and neuroblastoma cells and does not cause a significant increase in γH2AX foci in any of the studied cell lines.

PURPOSE: To study whether the application of femtosecond laser pulses for zona pellucida (ZP) drilling of blastocysts at the embryonic or abembryonic poles can promote hatching to start immediately through the hole formed and ensure high hatching rates and embryo viability. METHODS: Mouse blastocyst (E3.5) ZP were microdissected with femtosecond laser pulses (514-nm wavelength, 280-fs pulse duration, 2.5-kHz repetition rate) close to the trophoblast or inner cell mass (ICM). The sizes of the holes formed were in the range of 4.5–8.5 μm. Additional longitudinal incisions (5–7-μm long) on either side of the hole were created to determine whether hatching had started at the correct position. Embryos post-laser-assisted ZP drilling and intact embryos were cultured under standard conditions for 2 days; embryo quality was assessed twice daily. The hatching rates and in vitro and in vivo implantation rates (only for embryos with ZP dissected close to the ICM) were estimated. RESULTS: Femtosecond laser–assisted ZP drilling at the early blastocyst stage facilitated embryo hatching to start at the artificial opening with probability approaching 100%. Despite the artificial opening’s small size, no embryo trapping during hatching was observed. Both experimental groups had higher hatching rates than the control groups (93.3–94.7% vs. 83.3–85.7%, respectively). The in vitro implantation rate was comparable with that of the control group (92.3% vs. 95.4%). No statistically significant differences were obtained in the in vivo implantation rates between the experimental and control groups. CONCLUSIONS: Blastocyst-stage femtosecond laser microsurgery of ZP is fast and delicate and enables the hatching process to be initiated in a controlled manner through a relatively small opening, with no embryo trapping.

Two noncontact techniques based on the use of ultrashort laser pulses are presented for assisted reproductive technologies. The first creates a unique alphanumeric code on an embryo’s envelope to simplify its identification during the period of preimplantation development. The second ensures the embryo will start to hatch at a prescribed site via laser-assisted drilling of its shell at the early blastocyst stage, where the inner cell mass and trophectoderm cells can be distinguished clearly.

Results are presented from studying the effect of broadband pulses of terahertz (THz) radiation with a peak intensity of ~30 GW cm−2 and an electric field strength of ~3.5 MV cm−1 on fibroblasts. Data are obtained on the kinetics of changes in the number of foci of phosphorylated histone γH2AX, which are markers of DNA double-strand breaks. The values of the foci remain unchanged 24 h after irradiation.

For the first time, the data have been obtained on the effects of high-intensity terahertz (THz) radiation (with the intensity of 30 GW/cm2, electric field strength of 3.5 MV/cm) on human skin fibroblasts. A quantitative estimation of the number of histone Н2АХ foci of phosphorylation was performed. The number of foci per cell was studied depending on the irradiation time, as well as on the THz pulse energy. The performed studies have shown that the appearance of the foci is not related to either the oxidative stress (the cells preserve their morphology, cytoskeleton structure, and the reactive oxygen species content does not exceed the control values), or the thermal effect of THz radiation. The prolonged irradiation of fibroblasts also did not result in a decrease of their proliferative index.

Although the use of lasers in medical diagnosis and therapies, as well as in fundamental biomedical research is now almost routine, advanced laser sources and new laser-based methods continue to emerge. Due to the unique ability of ultrashort laser pulses to deposit energy into a microscopic volume in the bulk of a transparent material without disrupting the surrounding tissues, the ultrashort laser-based microsurgery of cells and subcellular components within structurally complex and fragile specimens such as embryos is becoming an important tool in developmental biology and reproductive medicine. In this review, we discuss the mechanisms of ultrashort laser pulse interaction with the matter, advantages of their application for oocyte and preimplantation embryo microsurgery (e.g., for oocyte/blastomere enucleation and embryonic cell fusion), as well as for nonlinear optical microscopy for studying the dynamics of embryonic development and embryo quality assessment. Moreover, we focus on ultrashort laser-based approaches and techniques that are increasingly being applied in the fundamental research and have the potential for successful translation into the IVF (in vitro fertilization) clinics, such as laser-mediated individual embryo labelling and controlled laser-assisted hatching.

Exposure of cells or biological tissues to high-power pulses of terahertz (THz) radiation leads to changes in a variety of intracellular processes. However, the role of heating effects due to strong absorption of THz radiation by water molecules still stays unclear. In this study, we performed numerical modelling in order to estimate the thermal impact on water of a single THz pulse as well as a series of THz pulses. A finite-element (FE) model that provides numerical solutions for the heat conduction equation is employed to compute the temperature increase. A simple expression for temperature estimation in the center of the spot of THz radiation is presented for given frequency and fluence of the THz pulse. It has been demonstrated that thermal effect is determined by either the average power of radiation or by the fluence of a single THz pulse depending on pulse repetition rate. Human dermal fibroblasts have been exposed to THz pulses (with an energy of $$15\,\upmu \hbox {J}$$ 15 μ J and repetition rate of 100 Hz) to estimate the thermal effect. Analysis of heat shock proteins expression has demonstrated no statistically significant difference ($$p < 0.05$$ p < 0.05 ) between control and experimental groups after 3 h of irradiation.

We apply femtosecond laser pulses for precise microsurgery of mammalian embryos at the blastocyst stage in order to extend the range of noninvasive methods in the Assisted Reproductive Techniques (ART), increase their safety and effectiveness. © 2021 The Author(s)

We report on the investigation of the biological effects of high-power pulsed broadband terahertz (THz) radiation on human skin fibroblasts. Cells were exposed to THz pulses with peak intensity ~30 GW/cm2 and electrical field strength ~3.5 MV/cm for 1.5 hours. Phosphorylation of H2AX (γH2AX foci) can be caused by different reasons including DNA double stand breaks, heat induction and can be related to chromosomes stability. However, the γH2AX foci seem to be a proper marker for detection of the effect of intense terahertz pulses on cells. The kinetics of phosphorylated histone H2AX foci post terahertz radiation exposure is analyzed. We found that the number of phosphorylated H2AX foci in human skin fibroblasts remained almost unchanged within 24 hours following terahertz exposure.

Two femtosecond laser-based techniques for embryo microsurgery are proposed. The first one uses laser to create code on the embryo envelope and minimize the risk of embryo mix-up. The second one enables laser-assisted hatching to be performed at the early blastocyst stage (when the inner cell mass and the trophoblast are distinguished) to initiate starting of hatching at the prescribed site.

We present the results of studying viability of human skin fibroblasts exposed to pulses of THz radiation with the peak intensity and electric field strength of 32 GW/cm2 and 3.5 MV/cm, respectively, for 90 minutes. Activation of the cascade of proapoptotic enzymes (not leading to cell apoptosis) and inhibition of the ROS action on cells were found.

The appearance of modern sources and detectors of terahertz radiation (1011–1013 Hz) stimulated the rapid development of practical applications for radiation in this frequency range. Therefore, the question of the safety of terahertz radiation for living objects was sharply raised. In this review, we present an analysis of research on this issue published from 2010 to the present. A brief description of the most significant works performed before 2010 is given. Particular attention is paid to the sources of terahertz radiation used in the studies and the results of experimental work on the study of possible bioeffects when such radiation is applied to both individual cell lines and microorganisms and animals generally.

According statistics, fillers occupy a leading position among non-surgical procedures. Despite their diversity in Russia, the evidence base for the treatment of age-related changes in the skin according to number of clinical and instrumental methods in the diagnostic is not enough. The combination of hyaluronic acid (HA) injections with fillers is pathogenetically justified. Therefore the search for scientifically based protocols for the correction of skin ageing is an actual trend in cosmetology and dermatology. Purpose. To assess the safety and effectiveness of correction of involuntary changes in face and neck skin with drugs based on stabilized hyaluronic acid. Material and methods. 35 women aged 30-65 years were enrolled into two groups by simple randomization. Group I received monotherapy with HA fillers, patients of group II - complex rejuvenation therapy for face and neck: fillers and course of vitalization stabilized HA. The efficasy was assessed according to the Global Aesthetic Improvement Scale (GAIS) on the 1st(M01), 2nd (M02), 3rd (M3), 6th (M06) month of complex therapy instrumental methods (cutometry, corneometry). Safety was assessed during 12 months of follow-up and ultrasound examination of the facial soft tissues. Results. The safety and efficacy injections of stabilized HA have been clinically confirmed. The advantages of complex therapy of fillers and the course of vitalization are shown

Аналізуються підходи мінімізації часу для отримання необхідної інформації з бази даних, а також критерії та параметри запитів, яких необхідно дотримуватися у процесі розробки. Розглядаються питаннястворення та оптимізації запитів для підвищення продуктивності, що дозволяють зробити функціонуваннябази даних більш ефективною. Обґрунтовано необхідності використання даних підходів в різних структурах.

An overview of the main methods of terahertz spectroscopy used for the detection of gases and gas mixtures is presented. Special attention is given to the methods and equipment used for remote express sensing of gases in the atmosphere to ensure a quick and high-precision identification of gases which is a relevant task important both from fundamental and applied points of view. The developed to date methods are analyzed and their parameters, which are largely determined by the available equipment, are discussed. The techniques and equipment used for generation and detection of terahertz radiation are considered including new trends in terahertz technology, emergence of new types of radiation sources, and upgrading of existing ones. Data on the use of the terahertz spectroscopy for the detection of gases in the laboratory and in open air are summarized. Key challenges and prospects for further application of the terahertz spectroscopy are outlined.

In this study, we aimed to develop a novel femtosecond laser-based technique for individual embryo tagging. We have demonstrated for the first time the possibility to create individual alphanumeric codes be means of femtosecond laser microsurgery directly on embryo’s outer shell. Femtosecond laser pulses (wavelength of 514 nm, pulse duration of 280 fs, repetition rate of 2.5 kHz, pulse energy of 20 nJ) were applied for precise alphanumeric code engraving on the zona pellucida of mouse embryos at the zygote stage. The code consisted of 4-5 characters (numerical and/or alphabetical) typically. Embryo quality assessment was performed every 24 hours post laser-assisted marking by light microscopy and compared with that of non-treated control embryos. The codes engraved could be clearly recognized until the thinning of the zona pellucida prior to hatching. No differences in morphology and developmental rates of laser-treated embryos and control embryos were found. Our results demonstrate the suitability of femtosecond laser as a novel tool for noninvasive embryo tagging, enabling embryo identification from day 0.5 post coitum to at least early blastocyst stage. The technique proposed is relatively fast, reliable and simple, and can be fully automated in the future. It can be performed in a contactless mode under sterile conditions and does not require any additional equipment (except microscope) to visualize the code and to identify the embryo. As far as femtosecond lasers offer several important advantages (such as high precision, minimal invasiveness, versatility etc.) over conventional milli/microsecond lasers we believe that further advances in ultrafast laser technology aimed at reducing complexity, size and high price of femtosecond lasers will help them gain popularity in the field of assisted reproduction.

PURPOSE: Our purpose was to study whether application of femtosecond laser pulses for alphanumeric code marking in the volume of zona pellucida (ZP) could be effective and reliable approach for direct tagging of preimplantation embryos. METHODS: Femtosecond laser pulses (wavelength of 514 nm, pulse duration of 280 fs, repetition rate of 2.5 kHz, pulse energy of 20 nJ) were applied for precise alphanumeric code engraving on the ZP of mouse embryos at the zygote stage for individual embryo marking and their accurate identification. Embryo quality assessment every 24 h post laser-assisted marking as well as immunofluorescence staining (for ICM/TE cell number ratio calculation) were performed. RESULTS: Initial experiments have started with embryo marking in a single equatorial plane. The codes engraved could be clearly recognized until the thinning of the ZP prior to hatching. Since embryo may change its orientation during the ART cycle, multi-plane code engraving seems to be more practical for simplifying the process of code searching and embryo identification. We have marked the ZP in three planes, and no decrease in developmental rates as well as no morphological changes of embryos post laser-assisted engraving have been observed as compared to control group embryos. CONCLUSIONS: Our results demonstrate the suitability of femtosecond laser as a novel tool for noninvasive embryo tagging, enabling embryo identification from day 0.5 post coitum to at least early blastocyst stage. Thus, the versatility and the potential use of femtosecond lasers in the field of developmental biology and assisted reproduction have been shown.

Femtosecond laser pulses were applied for precise alphanumeric code engraving on the zona pellucida (ZP) of mouse zygotes for individual embryo marking and their identification. The optimal range of laser pulse energies required for safe ZP microsurgery has been determined. ZP was marked with codes in three different planes to simplify the process of embryo identification. No decrease in developmental rates and no morphological changes of embryos post laser-assisted engraving have been observed. ZP thickness of embryos post laser-assisted code engraving has been shown to differ significantly from that of control group embryos at the hatching stage. Due to moderate ZP thinning as compared to its initial width at 0.5 dpc (days post coitum), readability of the code degrades slightly and it still remains recognizable even at hatching stage. Our results demonstrate that application of femtosecond laser radiation could be an effective approach for noninvasive direct embryo tagging, enabling embryo identification for the whole period of preimplantation development.

In this study, modern techniques of laser microsurgery of cell spheroids have been used to develop a new simple, reproducible model for studying the mechanisms of repair and regeneration in vitro. Nanosecond laser pulses were applied to perform a microdissection of the outer and the inner zones of the spheroids from dermal fibroblasts. To achieve effective dissection and preservation of spheroid viability, the optimal parameters were chosen: 355 nm wavelength, 100 Hz frequency, 2 ns pulse duration, laser pulses in the range of 7–9 μJ. After microdissection, we observed injury of the spheroids: the edges of the wound surface opened and the angular opening reached a value of more than 180°. As early as during the first hour after spheroid microdissection with laser radiation, the surviving cells changed their shape: cells on the spheroid surface and directly in the damaged area became rounded. One day after microdissection, the structure of the spheroids began to partially recover, the cells in the surface layers began to take the original flattened shape; debris of dead damaged cells and their fragments was gradually cleared from the spheroid composition. In the proposed model, the first data on stimulation of structure recovery of injured spheroids from dermal fibroblasts with a P199 synthetic polypeptide, which is used in cosmetology for the initiation of antiaging and regenerative effects in the skin, were received. After microdissection, recovery of the spheroids structure with a few surface layers of flattened imbricated arranged cells and polygonal cells of the inner zone in the presence of P199 peptide was faster than in the control group, and was completed within 7 days, presumably due to the remodeling of the survived cells.

Modern techniques of laser microsurgery of cell spheroids were used to develop a new simple reproducible model for studying repair and regeneration in vitro. Nanosecond laser pulses (wavelength 355 nm, frequency 100 Hz, pulse duration 2 ns) were applied to perform a microdissection of the outer and the inner zones of human bone marrow multipotent mesenchymal stromal cells (BM MMSC) spheroids. To achieve effective dissection and preservation of spheroid viability, the energy of laser pulses was optimized and adjusted in the range 7-9 μJ. After microdissection, the edges of the wound surface opened and the angular opening reached a value of more than 180°. The destruction of the initial spheroid structure was observed in the wound area, with surviving cells changing their shape into a round one. Partial restoration of a spheroid form took place in the first six hours. The complete structure restoration accompanying the reparative processes occurred gradually over seven days due to remodelling of surviving cells., Summary: The technique of precise nanosecond laser microsurgery of mesenchymal cell spheroids was used to develop a new simple reproducible model for studying repair and regeneration in vitro.

Terahertz (THz) waves can influence a diverse spectrum of cellular processes. In the present study, we focus on the effect of high-power broadband THz pulses on cell culture. An experimental setup for long-term irradiation of cells with THz pulses with intensities of about 32 GW/cm2 has been developed. Human skin fibroblasts were exposed to THz pulses with a field strength of about 3.5 MV/cm for 90 min. Preliminary results on the THz-induced apoptosis process in cells are presented.

Technique of laser microsurgery of cell spheroids with nanosecond laser pulses was used to develop a new simple reproducible model for studying regeneration in vitro. Wound restoration accompanying the reparative processes occurred gradually over seven days due to rearrangement of surviving non-proliferating cells. Skin anti-ageing drugs can be tested on the developed model of cell spheroid's regeneration.

Modern laser technologies have a wide range of scientific, commercial, medical and other applications. In medicine, lasers are used both for diagnostic, therapeutic, and surgical purposes. Safety of laser radiation in assisted reproductive technologies is discussed in the paper. Efficiency of using femtosecond (fs) laser pulses to perform noncontact embryo biopsy as well as laser-assisted hatching is shown. First results on femtosecond laser marking on the surface of embryo outer shell for individual embryo tagging are also presented. Question of safety of THz radiation for living objects (starting at the cellular level and ending with the organism in whole) is still a matter of controversy and requires further study. Experimental study of high-power THz pulses effect on living 2D cell culture is presented. MSC cells are exposed to multiple (from 80 to 100) THz pulses with intensities up to 1 MV/cm. No short-term damage effects are observed during first hours post cell irradiation.

We report the results of experiments on estimation of femtosecond laser threshold intensity at which nanoparticles are removed from the substrate surface. The studies are performed with nanoparticles obtained by femtosecond laser ablation of pure aluminium in distilled water. The attenuation (or extinction, i.e. absorption and scattering) spectra of nanoparticles are measured at room temperature in the UV and optical wavelength ranges. The size of nanoparticles is determined using atomic force microscopy. A new method of scanning photoluminescence is proposed to evaluate the threshold of nanoparticle removal from the surface of a glass substrate exposed to IR femtosecond laser pulses with intensities 1011 – 1013 W cm-2.

Ultrashort laser pulses have enabled highly precise and delicate processing of biological specimens. We present the results of using femtosecond laser pulses for dissection of zona pellucida (ZP) in mouse embryos during assisted hatching procedure. We studied the effects of application of femtosecond laser radiation in the infrared (1028 nm) and visible (514 nm) wavelength ranges. Laser irradiation parameters were optimized so as not to compromise the viability of the treated embryos. We have demonstrated that application of femtosecond laser pulses with the energies in the range of 250–320 nJ (for the wavelength of 1028 nm) and 47–112 nJ (for 514 nm) resulted in efficient ZP dissection. Femtosecond laser-assisted ZP drilling does not slow down the development of pre-implantation embryos and leads to 90–95% frequency of complete hatching. The thermal effects can be significantly lower when femtosecond lasers are used as compared to continuous wave or long-pulse lasers. It is crucial when dealing with living cells or organisms. By optimizing femtosecond laser radiation parameters assisted hatching as well as a wide range of embryo-surgical procedures can be efficiently performed, thus creating a great potential of using femtosecond lasers as a multi-purpose “tool of choice” for specialists in the fields of embryology and developmental biology.

We demonstrate that one of the key steps of preimplantation genetic diagnosis called embryo biopsy can be successfully performed in noncontact mode by means of femtosecond laser scalpel and optical tweezers. Embryo biopsy was carried out in late-stage mouse preimplantation embryos. Femtosecond laser pulses were applied to detach the desired amount of trophectoderm cells from the blastocyst, while the optical tweezers trapped the cells and moved them out of the embryo. The parameters of laser radiation were optimized so as to efficiently perform embryo biopsy and preserve the viability of the treated embryos.

We present the experimental results for the absorption spectra and photoluminescence of silicon nanoparticles synthesized by femtosecond laser ablation in distilled water under action of femtosecond laser pulses at a wavelength of 1048 nm with intensities in the range from 1010 to 1012 W/cm2.

In this paper we report the experimental data on modification and destruction of gold nanorods under action of single infrared femtosecond laser pulses in case of plasmon resonance at laser wavelength. The data on laser energy density, at which the shape of gold nanorods laid on silicon substrate in air conditions, is presented.

This paper provides a brief overview of the current state of research in the field of laser microsurgery of preimplantation embryos. The combined system femtosecond laser tweezers-scalpel developed in JIHT RAS is described. A scheme of device and peculiarities of functioning its nodes as well as the ground for the choice of their parameters are presented. The results of the development of methodology for noncontact polar body biopsy of the preimplantation embryo are also presented to demonstrate the potentials of the combined multi-purpose system femtosecond laser tweezers-scalpel.

We have studied the efficiency of microsurgery of a cell membrane in mesenchymal stem cells and the posterior cell viability under the localised short-time action of femtosecond IR laser pulses aimed at noncontact delivery of specified substances into the cells.

IR femtosecond laser pulses were used for microsurgery of a cell membrane aimed at local and short-duration change in its permeability and injection of specified extracellular substances into the cells. The possibility of noncontact laser delivery of the propidium iodide fluorescent dye and the pEGFP plasmid, encoding the green fluorescent protein, into the cells with preservation of the cell viability was demonstrated.

The results are presented of the works in the field of development of equipment, investigation techniques, and technologies for biology and medicine performed in the Joint Institute for High Temperatures of the Russian Academy of Scienses (JIHT RAS). On the base of the new generation infrared femtosecond lasers, the experimental models are developed and manufactured of laser tweezers, scalpel, and the “tweezers-scalpel” combined system. The results are presented of the experimental studies on the noncontact mammalian cell fusion (blastomeres of mouse embryos on day 1.5 of development) by means of the femtosecond laser pulses.

The faciometric's researches results in this article, to a floor-chennyh are discussed at inspection of inhabitants of the Chuvashiya divided into three subregions of biosphere with the account before spent biogeochemical division into districts. Also the oral cavity volume by own technique and influence on the given indicators macroglossii is investigated.

Laser microsurgery has enabled us to make highly precise and delicate processing of living biological specimens. We present the results of using femtosecond (fs) laser pulses in assisted reproductive technologies. Femtosecond laser dissection of outer shells of embryos (so-called laser-assisted hatching) as well as laser-mediated detachment of the desired amount of trophectoderm cells (so-called embryo biopsy) required for preimplantaion genetic diagnosis were successfully performed. The parameters of laser radiation were optimized so as to efficiently perform embryo biopsy and preserve the viability of the treated embryos. Effects of application of fs-laser radiation in the infrared (1028 nm) and visible (514 nm) wavelength ranges were studied. We also applied laser microsurgery to develop a new simple reproducible model for studying repair and regeneration in vitro. Nanosecond laser pulses were applied to perform localized microdissection of cell spheroids. After microdissection, the edges of the wound surface opened, the destruction of the initial spheroid structure was observed in the wound area, with surviving cells changing their shape into a round one. It was shown that the spheroid form partially restored in the first six hours with subsequent complete restoration within seven days due to remodeling of surviving cells.

Near-infrared femtosecond laser pulses were applied to initiate reversible permeabilization of cell membrane and inject extrinsic substances into the target cells. Successful laser-based injection of a membrane impermeable dye, as well as plasmid DNA was demonstrated.

Ultrashort laser pulses have enabled highly precise and delicate processing of biological specimens. We present the results of using femtosecond (fs) laser pulses for dissection of zona pellucida (ZP) in mouse embryos during assisted hatching procedure and for trophectoderm biopsy as well. We studied the effects of application of fs laser radiation in the infrared (1028 nm) and visible (514 nm) wavelength ranges. Laser irradiation parameters were optimized so as not to compromise the viability of the treated embryos. Embryo biopsy was carried out in late-stage mouse preimplantation embryos. Femtosecond laser pulses were applied to detach the desired amount of trophectoderm cells from the blastocyst, while the optical tweezers trapped the cells and moved them out of the embryo. The parameters of laser radiation were optimized so as to efficiently perform embryo biopsy and preserve the viability of the treated embryos. The thermal effects can be significantly lower when fs lasers are used as compared to CW or long-pulse lasers. It is crucial when dealing with living cells or organisms.

We report on results of using femtosecond laserscalpel for microsurgery of plasma membrane ofliving cells. Femtosecond laser pulses were appliedto initiate cell fusion as well as to performreversible permeabilization of cell membranerequired for efficient injection of extrinsicsubstances into the target cells. Laser-based cellfusion of mammalian embryo blastomeres as wellas fusion of cell bodies of neurons of molluskLymnaea stagnalis were successfully carried out byapplying single femtosecond laser pulses (secondharmonic of a Cr:Forsterite laser system) 620 nm,100 fs with the fluences of 0.42-0.71 J/cm2. It wasshown that the fusion of cells was completed within5-60 minutes depending on the cell type. Successfulpermeabilization of a cell membrane andoptoinjection of a membrane impermeable dye wasperformed with the help of a compact laser systemfor cell microsurgery DissCell-F (ytterbium laser,1050 nm, 75 MHz, ~115 fs). In both cases the laserirradiation parameters were thoroughly optimized toachieve high viability of treated cells and highefficiency of the procedures of cell fusion andoptical injection.

We employed femtosecond (fs) laser pulses to solve important biomedical and biotechnology problems, embryo biopsy and cell fusion respectively. We report on the results of fully contactless laser-mediated polar body (PB) and trophectoderm (TE) biopsy of early mammalian embryos. In the former case the fs laser scalpel (Cr:Forsterite seed oscillator and a regenerative amplifier, 100 fs, 10 Hz) was initially used to drill an opening in the outer covering of the embryo, and then the PB was extracted out of the zygote by means of optical tweezers (cw fiber laser, 1064 nm). In the latter case the laser scalpel was employed to dissect 5-7 TE cells that had just left the zona pellucida (ZP) during the hatching. The energy of laser pulses was thoroughly optimized to prevent cell damage and provide high viability of treated cells. Morphological and fluorescent analysis showed that femtosecond laser-based embryo biopsy did not compromise further in vitro embryo development. We also demonstrated the possibilities of using fs laser pulses for cell fusion. The contact border of the blastomeres of two-cell mouse embryos was perforated by a single fs-laser pulse with energy of 30-50 nJ. The blastomeres fusion process was usually complete within ∼60 min. In conclusion, the proposed techniques of laser microprocessing of living cells enable accurate, contamination-free, simple and quick performance of the procedures, and thus show a great potential for using fs lasers as a microsurgical tool.

We report observing anti-Stokes broadband radiation induced in gold nanorods by ultrashort laser pulses. The radiation is in the visible spectral range along with the second harmonic peak. Unlike conventional photoluminescence of metal nanoparticles, the energy of the excitation photons is smaller than the gap between the top of the d band and the Fermi level. Because the gold nanorods are irradiated with a pulse whose time is shorter than the electron–phonon equilibration time in gold, the energy is absorbed by s/p band electrons, creating a temperature difference between the electrons and the lattice, as described by the two-temperature model. Therefore, we identify the origin of the observed radiation as the recombination of hot conduction electrons with the d band holes created by the same ultrashort laser pulse.

Introduction: Embryo biopsy is a very important part of preimplantation genetic diagnosis. Nowadays the most popular method for embryo biopsy is mechanical method, but it requires timeconsuming pipette preparation, extensive practice and can lead to risk of embryo contamination and damage. We develop a new contactless technology for trophectoderm biopsy. The laser system with the functions of laser scalpel optical tweezers was created in the Joined Institute for High Temperatures RAS at the laboratory of laser plasma headed by M.B. Agranat.