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Mesenchymal stem cells (MSCs) being injected into the body can stimulate or decelerate carcinogenesis. Here, the direction of influence of human placenta‐derived MSCs (P‐MSCs) on the Lewis lung carcinoma (LLC) tumor development and metastatic potential is investigated in C57BL/6 mice depending on the injection method. After intramuscular co‐inoculation of LLC and P‐MSCs (LLC + P‐MSCs), the growth of primary tumor and angiogenesis are slowed down compared to the control LLC on the 15th day. This is explained by the fact of a decrease in the secretion of proangiogenic factors during in vitro co‐cultivation of an equal amount of LLC and P‐MSCs. When P‐MSCs are intravenously (i.v.) injected in the mice with developing LLC (LLC + P‐MSCs(i.v.)), the tumor growth and angiogenesis are stimulated on the 15th day. A highly activated secretion of proangiogenic factors by P‐MSCs in a similar in vitro model can explain this. In both the models compared to the control on the 23rd day, there is no significant difference in the tumor growth, while angiogenesis remains correspondingly decelerated or stimulated. However, in both the models, the total volume and number of lung metastases constantly increase compared to the control: it is mainly due to small‐size metastases for LLC + P‐MSCs(i.v.) and larger ones for LLC + P‐MSCs. The increase in the rate of LLC cell dissemination after the injection of P‐MSCs is explained by the disordered polyploidy and chromosomal instability, leading to an increase in migration and invasion of cancer cells. After LLC + P‐MSCs co‐inoculation, the tumor cell karyotype has the most complex and heterogeneous chromosomal structure. These findings indicate a bidirectional effect of P‐MSCs on the growth of LLC in the early periods after injection, depending on the injection method, and, correspondingly, the number of contacting cells. However, regardless of the injection method, P‐MSCs are shown to increase LLC aggressiveness related to cancer‐associated angiogenesis and metastasis activation in the long term. [ABSTRACT FROM AUTHOR]

The ability of stimuli‐responsive materials to respond to external stimuli depends on their intra‐ and intermolecular interactions, which, in turn, are governed by changes in the material composition. Here, the importance of these factors for new heat and light‐sensitive latexes of core‐shell nanoparticles is reported with the polystyrene core, the poly(N‐isopropylacrylamide) (PNIPAM) shell containing doped poly(3,4‐ethylenedioxythiophene) (PEDOT). It is found that hydrogen bonding, C═O─π aromatic, hydrophilic‐hydrophobic interactions in the shell cause conformational changes in PNIPAM similar to those occurring in the PNIPAM coil‐globule transition. Depending on the EDOT:PS@PNIPAM feed ratio and the PEDOT content in PNIPAM shells, these interactions and changes affect nanoparticle sizes and are responsible for shifting the lower critical solution temperature (LCST) of PNIPAM in the shell from 32.1 to 33.9 °C. The core‐shell morphology of nanoparticles is maintained only for latexes with EDOT feed to ≈9 wt.%. At the higher EDOT content, PNIPAM shells are destroyed. Synthesized PS@PNIPAM‐PEDOT latexes demonstrate temperature‐dependent behavior and produce a photothermal effect under NIR irradiation, which allows for a rise of their temperature above LCST. This dual stimuli (heat and light) responsiveness suggests an important possibility for these latexes to be used for drug or diagnostic agent delivery. [ABSTRACT FROM AUTHOR]

Noninvasive sonodynamic therapy (SDT) shows promise for brain glioma treatment due to deep tissue‐penetrating capabilities (>10 cm) of ultrasound and high spatial resolutions. Yet, this technique is hindered by inefficient production of reactive oxygen species (ROS), resulting from the hypoxic tumor microenvironment (TME), high level of ROS scavenger glutathione (GSH), and the inability to visualize glioma in vivo for precise treatment management and monitoring in current sonosentizers. To address these challenges, we fabricated a core‐shell heterostructure sonosensitizer (labeled as DFM), in which meso‐tetra (4‐carboxyphenyl) porphine (TCPP) porphyrin metal‐organic frameworks (MOF, PCN‐224(Fe)) serve as a porous shell to contain approved chemotherapeutics sorafenib (SRF) to effectively inhibit GSH synthesis, while NaErF4:Yb@NaLuF4 nanoparticles as the core provide TME‐responsive NIR IIb (≈1500–1800 nm) luminescence at 1525 for precise optical imaging. Coordination of Fe3+ into the macrocycle of TCPP at the MOFs shell is found to, besides triggering ferroptosis, reduce TCPP phosphorescence (23% decrease) and increase the triplet state (T1) oxygen quenching, substantially promoting the singlet oxygen generation (2.6‐fold increase). Furthermore, GSH in TME facilitates the reduction of Fe3+ to Fe2+, thereby eliminating the luminescence quenching of Fe3+ and augmenting the NIR IIb luminescence of Er3+ (5‐fold increase) for nanoagents accumulation imaging in intracranial glioma, realizing dynamical monitoring of SDT processes. Compared to control groups, in vitro and in vivo experiments confirm the effective ROS generation and results in a 6‐fold volume reduction of brain gliomas, reaching a survival rate of 80% at 30 days posttreatment. [ABSTRACT FROM AUTHOR]

Laser pyrolysis, an aerosol nanosynthesis technique, uses a 10.6 μm CO2 laser to rapidly heat precursors to induce decomposition and particle nucleation. A photosensitizing agent, usually SF6, absorbs the laser beam and transfers energy to the precursors. Here, we exploit the presence of SF6 in the system and use it as a safe source of fluorine to synthesize NaYF4 nanocrystals in a single-step process. NaYF4 is an excellent host for rare-earth ions to create upconverting nanocrystals (UCNCs) that absorb infrared photons and emit at shorter wavelength. We thus dope the NaYF4 nanocrystals during synthesis with ytterbium as a sensitizer and erbium, thulium, or holmium as an upconversion emitter. Each emitter produces upconversion emission at specific wavelengths in the visible spectral range after near-infrared light (∼980 nm peaked emission from laser diode) is absorbed by ytterbium followed by energy transfer to emitter. We then show that calcining these materials, in a simple second step, dramatically increases upconversion emission intensity. Finally, we optimize the laser pyrolysis process and postsynthesis calcination to produce the most intense emission at each emission color. We also show that these laser-synthesized UCNCs can be dispersed in a broad range of solvents and retain their visible upconversion emission. This dispersibility could be particularly valuable in creating inks for printing in anticounterfeiting applications. Proof-of-concept use of the synthesized UCNC for anticounterfeiting applications was demonstrated by drop-casting a dispersion of UCNC in stencils on paper, to create various luminescent patterns that were visible under irradiation by a 980 nm laser diode. Overall, this study demonstrates a promising vapor-phase route to rapid, single-step, continuous synthesis of lanthanide-doped fluoride nanomaterials for anticounterfeiting and related applications. [ABSTRACT FROM AUTHOR]

The photophysical properties of the thiopyrylium dye 1-S and the related thio (6-S0 and selenopyrylium (6-Se) analogues in aqueous solution were examined. It was shown that not only the fluorescence yield for the production of [1.sup.O.sub.2] increase upon binding to DAN in these systems but also the quantum yield.

The energy-transferring organically modified silica nanoparticles are described for two-photon photodynamic therapy. A multidisciplinary nanophotonic approach is used to show indirect excitation of the photosensitization through efficient two-photon excited intraparticle energy transfer from the dye aggregates in the intracellular environment of tumor cells.