Dental treatment of children under general anesthesia during the period of matrial law.

OBJECTIVE: Aim: To summarize the experience of providing dental medical care under general anesthesia to children from different regions of Ukraine during the martial law, taking into account the factors affecting the choice of optimal conditions for dental treatment. PATIENTS AND METHODS: Materials and Methods: Dental treatment under general anesthesia of 1,258 children from different regions of Ukraine has been performed since March 2022. The condition of the teeth (df, df+DMF, DMF) and hygienic state of the oral cavity (OHI-S) were determined. The level of awareness of parents regarding the preservation of children's dental health was studied through a questionnaire. RESULTS: Results: An unsatisfactory oral hygiene, a high level of caries were found in the vast majority of children. The highest df was observed in the group of children aged 3 to 6 years (7.14±0.33), which is significantly higher than in the group of children under 3 years of age (4.32±1.04, p≤0.05). The worst oral hygiene was observed in children aged 6-12 years (OHI-S 2.62±0.32). An insufficient level of awareness of parents and children regarding dental health was revealed. A total of 1,712 operations under general anesthesia were performed. The majority of patients could not regularly appear for follow-up examinations due to the forced departure from the country. CONCLUSION: Conclusions: The organization of dental treatment under general anesthesia allows solving a number of problems of dental care for children during the war.

RL2 Enhances the Elimination of Breast Cancer Cells by Doxorubicin.

RL2 (recombinant lactaptin 2), a recombinant analogon of the human milk protein Κ-Casein, induces mitophagy and cell death in breast carcinoma cells. Furthermore, RL2 was shown to enhance extrinsic apoptosis upon long-term treatment while inhibiting it upon short-term stimulation. However, the effects of RL2 on the action of chemotherapeutic drugs that induce the intrinsic apoptotic pathway have not been investigated to date. Here, we examined the effects of RL2 on the doxorubicin (DXR)-induced cell death in breast cancer cells with three different backgrounds. In particular, we used BT549 and MDA-MB-231 triple-negative breast cancer (TNBC) cells, T47D estrogen receptor alpha (ERα) positive cells, and SKBR3 human epidermal growth factor receptor 2 (HER2) positive cells. BT549, MDA-MB-231, and T47D cells showed a severe loss of cell viability upon RL2 treatment, accompanied by the induction of mitophagy. Furthermore, BT549, MDA-MB-231, and T47D cells could be sensitized towards DXR treatment with RL2, as evidenced by loss of cell viability. In contrast, SKBR3 cells showed almost no RL2-induced loss of cell viability when treated with RL2 alone, and RL2 did not sensitize SKBR3 cells towards DXR-mediated loss of cell viability. Bioinformatic analysis of gene expression showed an enrichment of genes controlling metabolism in SKBR3 cells compared to the other cell lines. This suggests that the metabolic status of the cells is important for their sensitivity to RL2. Taken together, we have shown that RL2 can enhance the intrinsic apoptotic pathway in TNBC and ERα-positive breast cancer cells, paving the way for the development of novel therapeutic strategies.

The Molecular Basis for Selectivity of the Cytotoxic Response of Lung Adenocarcinoma Cells to Cold Atmospheric Plasma.

The interaction of cold atmospheric plasma (CAP) with biotargets is accompanied by chemical reactions on their surfaces and insides, and it has great potential as an anticancer approach. This study discovers the molecular mechanisms that may explain the selective death of tumor cells under CAP exposure. To reach this goal, the transcriptional response to CAP treatment was analyzed in A549 lung adenocarcinoma cells and in lung-fibroblast Wi-38 cells. We found that the CAP treatment induced the common trend of response from A549 and Wi-38 cells-the p53 pathway, KRAS signaling, UV response, TNF-alpha signaling, and apoptosis-related processes were up-regulated in both cell lines. However, the amplitude of the response to CAP was more variable in the A549 cells. The CAP-dependent death of A549 cells was accompanied by DNA damage, cell-cycle arrest in G2/M, and the dysfunctional response of glutathione peroxidase 4 (GPx4). The activation of the genes of endoplasmic reticulum stress and ER lumens was detected only in the A549 cells. Transmission-electron microscopy confirmed the alteration of the morphology of the ER lumens in the A549 cells after the CAP exposure. It can be concluded that the responses to nuclear stress and ER stress constitute the main differences in the sensitivity of tumor and healthy cells to CAP exposure.

Laser-Activated Second Harmonic Generation in Flexible Membrane with Si Nanowires.

Nonlinear silicon photonics has a high compatibility with CMOS technology and therefore is particularly attractive for various purposes and applications. Second harmonic generation (SHG) in silicon nanowires (NWs) is widely studied for its high sensitivity to structural changes, low-cost fabrication, and efficient tunability of photonic properties. In this study, we report a fabrication and SHG study of Si nanowire/siloxane flexible membranes. The proposed highly transparent flexible membranes revealed a strong nonlinear response, which was enhanced via activation by an infrared laser beam. The vertical arrays of several nanometer-thin Si NWs effectively generate the SH signal after being exposed to femtosecond infrared laser irradiation in the spectral range of 800-1020 nm. The stable enhancement of SHG induced by laser exposure can be attributed to the functional modifications of the Si NW surface, which can be used for the development of efficient nonlinear platforms based on silicon. This study delivers a valuable contribution to the advancement of optical devices based on silicon and presents novel design and fabrication methods for infrared converters.

"Pulsed Hypoxia" Gradually Reprograms Breast Cancer Fibroblasts into Pro-Tumorigenic Cells via Mesenchymal-Epithelial Transition.

Hypoxia arises in most growing solid tumors and can lead to pleotropic effects that potentially increase tumor aggressiveness and resistance to therapy through regulation of the expression of genes associated with the epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET). The main goal of the current work was to obtain and investigate the intermediate phenotype of tumor cells undergoing the hypoxia-dependent transition from fibroblast to epithelial morphology. Primary breast cancer fibroblasts BrC4f, being cancer-associated fibroblasts, were subjected to one or two rounds of "pulsed hypoxia" (PH). PH induced transformation of fibroblast-shaped cells to semi-epithelial cells. Western blot analysis, fluorescent microscopy and flow cytometry of transformed cells demonstrated the decrease in the mesenchymal markers vimentin and N-cad and an increase in the epithelial marker E-cad. These cells kept mesenchymal markers αSMA and S100A4 and high ALDH activity. Real-time PCR data of the cells after one (BrC4f_Hyp1) and two (BrC4f_Hyp2) rounds of PH showed consistent up-regulation of TWIST1 gene as an early response and ZEB1/2 and SLUG transcriptional activity as a subsequent response. Reversion of BrC4f_Hyp2 cells to normoxia conditions converted them to epithelial-like cells (BrC4e) with decreased expression of EMT genes and up-regulation of MET-related OVOL2 and c-MYC genes. Transplantation of BrC4f and BrC4f_Hyp2 cells into SCID mice showed the acceleration of tumor growth up to 61.6% for BrC4f_Hyp2 cells. To summarize, rounds of PH imitate the MET process of tumorigenesis in which cancer-associated fibroblasts pass through intermediate stages and become more aggressive epithelial-like tumor cells.

Chloroquine Enhances Death in Lung Adenocarcinoma A549 Cells Exposed to Cold Atmospheric Plasma Jet.

Cold atmospheric plasma (CAP) is an intensively-studied approach for the treatment of malignant neoplasms. Various active oxygen and nitrogen compounds are believed to be the main cytotoxic effectors on biotargets; however, the comprehensive mechanism of CAP interaction with living cells and tissues remains elusive. In this study, we experimentally determined the optimal discharge regime (or semi-selective regime) for the direct CAP jet treatment of cancer cells, under which lung adenocarcinoma A549, A427 and NCI-H23 cells demonstrated substantial suppression of viability, coupled with a weak viability decrease of healthy lung fibroblasts Wi-38 and MRC-5. The death of CAP-exposed cancer and healthy cells under semi-selective conditions was caspase-dependent. We showed that there was an accumulation of lysosomes in the treated cells. The increased activity of lysosomal protease Cathepsin D, the transcriptional upregulation of autophagy-related MAPLC3B gene in cancer cells and the changes in autophagy-related proteins may have indicated the activation of autophagy. The addition of the autophagy inhibitor chloroquine (CQ) after the CAP jet treatment increased the death of A549 cancer cells in a synergistic manner and showed a low effect on the viability of CAP-treated Wi-38 cells. Downregulation of Drp1 mitochondrial protein and upregulation of PINK1 protein in CAP + CQ treated cells indicated that CQ increased the CAP-dependent destabilization of mitochondria. We concluded that CAP weakly activated pro-survival autophagy in irradiated cells, and CQ promoted CAP-dependent cell death due to the destabilization of autophagosomes formation and mitochondria homeostasis. To summarize, the combination of CAP treatment with CQ could be useful for the development of cold plasma-based antitumor approaches for clinical application.

Deep-Level Emission Tailoring in ZnO Nanostructures Grown via Hydrothermal Synthesis.

Zinc oxide (ZnO) nanostructures are widely used in various fields of science and technology due to their properties and ease of fabrication. To achieve the desired characteristics for subsequent device application, it is necessary to develop growth methods allowing for control over the nanostructures' morphology and crystallinity governing their optical and electronic properties. In this work, we grow ZnO nanostructures via hydrothermal synthesis using surfactants that significantly affect the growth kinetics. Nanostructures with geometry from nanowires to hexapods are obtained and studied with photoluminescence (PL) spectroscopy. Analysis of the photoluminescence spectra demonstrates pronounced exciton on a neutral donor UV emission in all of the samples. Changing the growth medium chemical composition affects the emission characteristics sufficiently. Apart the UV emission, nanostructures synthesized without the surfactants demonstrate deep-level emission in the visible range with a peak near 620 nm. Structures synthesized with the use of sodium citrate exhibit emission peak near 520 nm, and those with polyethylenimine do not exhibit the deep-level emission. Thus, we demonstrate the correlation between the hydrothermal growth conditions and the obtained ZnO nanostructures' optical properties, opening up new possibilities for their precise control and application in nanophotonics, UV-Vis and white light sources.

EGFR Transgene Stimulates Spontaneous Formation of MCF7 Breast Cancer Cells Spheroids with Partly Loss of HER3 Receptor.

Multicellular spheroids with 3D cell-cell interactions are a useful model to simulate the growth conditions of cancer. There is evidence that in tumor spheroids, the expression of various essential molecules is changed compared to the adherent form of cell cultures. These changes include growth factor receptors and ABC transporters and result in the enhanced invasiveness of the cells and drug resistance. It is known that breast adenocarcinoma MCF7 cells can spontaneously form 3D spheroids and such spheroids are characterized by high expression of EGFR/HER2, while the natural phenotype of MCF7 cells is EGFRlow/HER2low. Therefore, it was interesting to reveal if high epidermal growth factor receptor (EGFR) expression is sufficient for the conversion of adherent MCF7 to spheroids. In this study, an MCF7 cell line with high expression of EGFR was engineered using the retroviral transduction method. These MCF7-EGFR cells assembled in spheroids very quickly and grew predominantly as a 3D suspension culture with no special plates, scaffolds, growth supplements, or exogenous matrixes. These spheroids were characterized by a rounded shape with a well-defined external border and 100 µM median diameter. The sphere-forming ability of MCF7-EGFR cells was up to 5 times stronger than in MCF7wt cells. Thus, high EGFR expression was the initiation factor of conversion of adherent MCF7wt cells to spheroids. MCF7-EGFR spheroids were enriched by the cells with a cancer stem cell (CSC) phenotype CD24-/low/CD44- in comparison with parental MCF7wt cells and MCF7-EGFR adhesive cells. We suppose that these properties of MCF7-EGFR spheroids originate from the typical features of parental MCF7 cells. We showed the decreasing of HER3 receptors in MCF7-EGFR spheroids compared to that in MCFwt and in adherent MCF7-EGFR cells, and the same decrease was observed in the MCF7wt spheroids growing under the growth factors stimulation. To summarize, the expression of EGFR transgene in MCF7 cells stimulates rapid spheroids formation; these spheroids are enriched by CSC-like CD24-/CD44- cells, they partly lose HER3 receptors, and are characterized by a lower potency in drug resistance pomp activation compared to MCF7wt. These MCF7-EGFR spheroids are a useful cancer model for the development of anticancer drugs, including EGFR-targeted therapeutics.

Flexible Perovskite CsPbBr3 Light Emitting Devices Integrated with GaP Nanowire Arrays in Highly Transparent and Durable Functionalized Silicones.

The architecture of transparent contacts is of utmost importance for creation of efficient flexible light-emitting devices (LEDs) and other deformable electronic devices. We successfully combined the newly synthesized transparent and durable silicone rubbers and the semiconductor materials with original fabrication methods to design LEDs and demonstrate their significant flexibility. We developed electrodes based on a composite GaP nanowire-phenylethyl-functionalized silicone rubber membrane, improved with single-walled carbon nanotube films for a hybrid poly(ethylene oxide)-metal-halide perovskite (CsPbBr3) flexible green LED. The proposed approach provides a novel platform for fabrication of flexible hybrid optoelectronic devices.

XRD Evaluation of Wurtzite Phase in MBE Grown Self-Catalyzed GaP Nanowires.

Control and analysis of the crystal phase in semiconductor nanowires are of high importance due to the new possibilities for strain and band gap engineering for advanced nanoelectronic and nanophotonic devices. In this letter, we report the growth of the self-catalyzed GaP nanowires with a high concentration of wurtzite phase by molecular beam epitaxy on Si (111) and investigate their crystallinity. Varying the growth temperature and V/III flux ratio, we obtained wurtzite polytype segments with thicknesses in the range from several tens to 500 nm, which demonstrates the high potential of the phase bandgap engineering with highly crystalline self-catalyzed phosphide nanowires. The formation of rotational twins and wurtzite polymorph in vertical nanowires was observed through complex approach based on transmission electron microscopy, powder X-ray diffraction, and reciprocal space mapping. The phase composition, volume fraction of the crystalline phases, and wurtzite GaP lattice parameters were analyzed for the nanowires detached from the substrate. It is shown that the wurtzite phase formation occurs only in the vertically-oriented nanowires during vapor-liquid-solid growth, while the wurtzite phase is absent in GaP islands parasitically grown via the vapor-solid mechanism. The proposed approach can be used for the quantitative evaluation of the mean volume fraction of polytypic phase segments in heterostructured nanowires that are highly desirable for the optimization of growth technologies.

Uncovering molecular mechanisms of regulated cell death in the naked mole rat.

The naked mole rat (NMR), Heterocephalus glaber, is the longest-living rodent species, and is extraordinarily resistant to cancer and aging-related diseases. The molecular basis for these unique phenotypic traits of the NMR is under extensive research. However, the role of regulated cell death (RCD) in the longevity and the protection from cancer in the NMR is still largely unknown. RCD is a mechanism restricting the proliferation of damaged or premalignant cells, which counteracts aging and oncotransformation. In this study, DNA damage-induced cell death in NMR fibroblasts was investigated in comparison to RCD in fibroblasts from Mus musculus. The effects of methyl methanesulfonate, 5-fluorouracil, and etoposide in both cell types were examined using contemporary cell death analyses. Skin fibroblasts from Heterocephalus glaber were found to be more resistant to the action of DNA damaging agents compared to fibroblasts from Mus musculus. Strikingly, our results revealed that NMR cells also exhibit a limited apoptotic response and seem to undergo regulated necrosis. Taken together, this study provides new insights into the mechanisms of cell death in NMR expanding our understanding of longevity, and it paves the way towards the development of innovative therapeutic approaches.

Optimization of Optoelectronic Properties of Patterned Single-Walled Carbon Nanotube Films.

We propose a novel strategy to enhance optoelectrical properties of single-walled carbon nanotube (SWCNT) films for transparent electrode applications by film patterning. First, we theoretically considered the effect of the conducting pattern geometry on the film quality factor and then experimentally examined the calculated structures. We extend these results to show that the best characteristics of patterned SWCNT films can be achieved using the combination of initial film properties: low transmittance and high conductivity. The proposed strategy allows the patterned layers of SWCNTs to outperform the widely used indium-tin-oxide electrodes on both flexible and rigid substrates.

Structural and Optical Properties of Self-Catalyzed Axially Heterostructured GaPN/GaP Nanowires Embedded into a Flexible Silicone Membrane.

Controlled growth of heterostructured nanowires and mechanisms of their formation have been actively studied during the last decades due to perspectives of their implementation. Here, we report on the self-catalyzed growth of axially heterostructured GaPN/GaP nanowires on Si(111) by plasma-assisted molecular beam epitaxy. Nanowire composition and structural properties were examined by means of Raman microspectroscopy and transmission electron microscopy. To study the optical properties of the synthesized nanoheterostructures, the nanowire array was embedded into the silicone rubber membrane and further released from the growth substrate. The reported approach allows us to study the nanowire optical properties avoiding the response from the parasitically grown island layer. Photoluminescence and Raman studies reveal different nitrogen content in nanowires and parasitic island layer. The effect is discussed in terms of the difference in vapor solid and vapor liquid solid growth mechanisms. Photoluminescence studies at low temperature (5K) demonstrate the transition to the quasi-direct gap in the nanowires typical for diluted nitrides with low N-content. The bright room temperature photoluminescent response demonstrates the potential application of nanowire/polymer matrix in flexible optoelectronic devices.

Non-Thermal Plasma Application in Tumor-Bearing Mice Induces Increase of Serum HMGB1.

The application of cold atmospheric plasma (CAP) in cancer therapy could be one of the new anticancer strategies. In the current work, we used cold atmospheric plasma jet for the treatment of cultured cells and mice. We showed that CAP induced the death of MX-7 mouse rhabdomyosarcoma cells with the hallmarks of immunogenic cell death (ICD): calreticulin and heat shock protein 70 (HSP70) externalization and high-mobility group box 1 protein (HMGB1) release. The intensity of HMGB1 release after the CAP treatment correlated directly with the basal extracellular HMGB1 level. Releasing from dying cells, HMGB1 can act as a proinflammatory cytokine. Our in vivo study demonstrated that cold atmospheric plasma induces a short-term two-times increase in serum HMGB1 level only in tumor-bearing mice with no effect in healthy mice. These findings support our hypothesis that CAP-dependent HMGB1 release from dying cancer cells can change the serum HMGB1 level. At the same time, we showed a weak cytokine response to CAP irradiation in healthy mice that can characterize CAP as an immune-safety physical antitumor approach.

The Recombinant Fragment of Human κ-Casein Induces Cell Death by Targeting the Proteins of Mitochondrial Import in Breast Cancer Cells.

Breast cancer is still one of the most common cancers for women. Specified therapeutics are indispensable for optimal treatment. In previous studies, it has been shown that RL2, the recombinant fragment of human κ-Casein, induces cell death in breast cancer cells. However, the molecular mechanisms of RL2-induced cell death remain largely unknown. In this study, mechanisms of RL2-induced cell death in breast cancer cells were systematically investigated. In particular, we demonstrate that RL2 induces loss of mitochondrial membrane potential and cellular ATP loss followed by cell death in breast cancer cells. The mass spectrometry-based screen for RL2 interaction partners identified mitochondrial import protein TOM70 as a target of RL2, which was subsequently validated. Further to this, we show that RL2 is targeted to mitochondria after internalization into the cells, where it can also be found in the dimeric form. The importance of TOM70 and RL2 interaction in RL2-induced reduction in ATP levels was validated by siRNA-induced downregulation of TOM70, resulting in the partial rescue of ATP production. Taken together, this study demonstrates that RL2-TOM70 interaction plays a key role in RL2-mediated cell death and targeting this pathway may provide new therapeutic options for treating breast cancer.

Recombinant Lactaptin Induces Immunogenic Cell Death and Creates an Antitumor Vaccination Effect in Vivo with Enhancement by an IDO Inhibitor.

Natural compounds of various origins are intensively investigated for their antitumor activity. Potential benefits of antitumor therapy can be achieved when cytotoxic agents kill cancer cells and these dying cancer cells drive adoptive immunity to the tumor. This strategy was successfully demonstrated for chemotherapeutic drugs that induce immunogenic type of cell death (ICD) with release of DAMPs (danger associated molecular patterns) and exposure of "eat me" signals. In this study, we demonstrated that recombinant human milk peptide lactaptin (RL2) induces death of cancer cells with ICD hallmarks in vitro with the release of ATP and high-mobility group box 1 protein (HMGB1) and exposure of calreticulin and HSP70 on the external cell membrane. RL2-treated cancer cells were efficiently engulfed by phagocytic cells. Using the syngeneic mouse model, we demonstrated that RL2-treated MX-7 rhabdomyosarcoma cells confer long-term immune-mediated protection against challenge with live MX-7 cells. We also analyzed the combinatorial antitumor effect of vaccination with RL2-treated cells and the inhibition of indoleamine 2,3-dioxygenase (IDO) with ethyl pyruvate. Compared to solo anti-tumor immunization with RL2-treated cells, additional chemical inhibition of IDO demonstrated better long-term antitumor responses than vaccination alone.

Interplay Between Mitophagy and Apoptosis Defines a Cell Fate Upon Co-treatment of Breast Cancer Cells With a Recombinant Fragment of Human κ-Casein and Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand.

A recombinant fragment of human κ-Casein, termed RL2, induces cell death of breast cancer cells; however, molecular mechanisms of RL2-mediated cell death have remained largely unknown. In the current study, we have decoded the molecular mechanism of the RL2-mediated cell death and found that RL2 acts via the induction of mitophagy. This was monitored by the loss of adenosine triphosphate production, LC3B-II generation, and upregulation of BNIP3 and BNIP3L/NIX, as well as phosphatase and tensin homolog-induced kinase 1. Moreover, we have analyzed the cross talk of this pathway with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis upon combinatorial treatment with RL2 and TRAIL. Strikingly, we found two opposite effects of this co-treatment. RL2 had inhibitory effects on TRAIL-induced cell death upon short-term co-stimulation. In particular, RL2 treatment blocked TRAIL-mediated caspase activation, cell viability loss, and apoptosis, which was mediated via the downregulation of the core proapoptotic regulators. Contrary to short-term co-treatment, upon long-term co-stimulation, RL2 sensitized the cells toward TRAIL-induced cell death; the latter observation provides the basis for the development of therapeutic approaches in breast cancer cells. Collectively, our findings have important implications for cancer therapy and reveal the molecular switches of the cross talk between RL2-induced mitophagy and TRAIL-mediated apoptosis.

Nucleic Acids Delivery Into the Cells Using Pro-Apoptotic Protein Lactaptin.

Cell penetrating peptides (CPP) are promising agents for transporting diverse cargo into the cells. The amino acid sequence and the mechanism of lactaptin entry into the cells allow it to be included into CPP group. Lactaptin, the fragment of human milk kappa-casein, and recombinant lactaptin (RL2) were initially discovered as molecules that induced apoptosis of cultured cancer cells and did not affect non-malignant cells. Here, we analyzed the recombinant lactaptin potency to form complexes with nucleic acids and to act as a gene delivery system. To study RL2-dependent delivery, three type of nucleic acid were used as a models: plasmid DNA (pDNA), siRNA, and non-coding RNA which allow to detect intracellular localization through their functional activity. We have demonstrated that RL2 formed positively charged noncovalent 110-nm-sized complexes with enhanced green fluorescent protein (EGFP)-expressing plasmid DNA. Ca2+ ions stabilized these complexes, whereas polyanion heparin displaced DNA from the complexes. The functional activity of delivered nucleic acids were assessed by fluorescent microscopy using A549 lung adenocarcinoma cells and A431 epidermoid carcinoma cells. We observed that RL2:pDNA complexes provided EGFP expression in the treated cells and that strongly confirmed the entering pDNA into the cells. The efficiency of cell transformation by these complexes increased when RL2:pDNA ratio increased. Pre-treatment of the cells with anti-RL2 antibodies partly inhibited the entry of pDNA into the cells. RL2-mediated delivery of siRNA against EGFP was analyzed when A549 cells were co-transfected with EGFP-pDNA and RL2:siRNA complexes. siRNA against EGFP efficiently inhibited the expression of EGFP being delivered as RL2:siRNA complexes. We have previously demonstrated that non-coding U25 small nucleolar RNA (snoRNA) can decrease cell viability. Cancer cell transfection with RL2-snoRNA U25 complexes lead to a substantial decrease of cell viability, confirming the efficiency of snoRNA U25 delivery. Collectively, these findings indicate that recombinant lactaptin is able to deliver noncovalently associated nucleic acids into cancer cells in vitro.

Biological Kerker Effect Boosts Light Collection Efficiency in Plants.

Being the polymorphs of calcium carbonate (CaCO3), vaterite and calcite have attracted a great deal of attention as promising biomaterials for drug delivery and tissue engineering applications. Furthermore, they are important biogenic minerals, enabling living organisms to reach specific functions. In nature, vaterite and calcite monocrystals typically form self-assembled polycrystal micro- and nanoparticles, also referred to as spherulites. Here, we demonstrate that alpine plants belonging to the Saxifraga genus can tailor light scattering channels and utilize multipole interference effect to improve light collection efficiency via producing CaCO3 polycrystal nanoparticles on the margins of their leaves. To provide a clear physical background behind this concept, we study optical properties of artificially synthesized vaterite nanospherulites and reveal the phenomenon of directional light scattering. Dark-field spectroscopy measurements are supported by a comprehensive numerical analysis, accounting for the complex microstructure of particles. We demonstrate the appearance of generalized Kerker condition, where several higher order multipoles interfere constructively in the forward direction, governing the interaction phenomenon. As a result, highly directive forward light scattering from vaterite nanospherulites is observed in the entire visible range. Furthermore, ex vivo studies of microstructure and optical properties of leaves for the alpine plants Saxifraga "Southside Seedling" and Saxifraga Paniculata Ria are performed and underline the importance of the Kerker effect for these living organisms. Our results pave the way for a bioinspired strategy of efficient light collection by self-assembled polycrystal CaCO3 nanoparticles via tailoring light propagation directly to the photosynthetic tissue with minimal losses to undesired scattering channels.

Cytotoxic and Antitumor Activity of Lactaptin in Combination with Autophagy Inducers and Inhibitors.

Autophagy is a degradative process in which cellular organelles and proteins are recycled to restore homeostasis and cellular metabolism. Autophagy can be either a prosurvival or a prodeath process and remains one of the most fundamental processes for cell vitality. Thus autophagy modulation is an important approach for reinforcement anticancer therapeutics. Earlier we have demonstrated that recombinant analog of human milk protein lactaptin (RL2) induced apoptosis of various cultured cancer cells and activated lipidation of microtubule-associated protein 1 light chain 3 (LC3). In this study we investigated whether autophagy inhibitors-chloroquine (CQ), Ku55933 (Ku), and 3-methyladenine (3MA)-or inducer-rapamycin (Rap)-can enhance cytotoxic activity of lactaptin analog in cancer cells and its anticancer activity in the mice model. Western Blot analysis revealed that RL2 induced short-term autophagy in MDA-MB-231 and MCF-7 cells at early stages of incubation and that these data were confirmed by the transmission electron microscopy of autophagosome/autophagolysosome formation. RL2 stimulates reactive oxygen species (ROS) production, autophagosomes accumulation, upregulation of ATG5 with processing of LC3I to LC3II, and downregulation of p62/sequestosome 1 (p62). We have shown that autophagy modulators, CQ, Ku, and Rap, synergistically increased cytotoxicity of RL2, and RL2 with CQ induced autophagic cell death. In addition, CQ, Ku, and Rap in combination with RL2 decreased activity of lysosomal protease Cathepsin D. More importantly, combining RL2 with CQ, we improved antitumor effect in mice. Detected synergistic cytotoxic effects of both types of autophagy regulators, inhibitors, and inducers with RL2 against cancer cells allow us to believe that these combinations can be a basis for the new anticancer approach. Finally, we suppose that CQ and Rap promoting of short-term RL2-induced autophagy interlinks with final autophagic cell death.