INTRODUCTION: A critical step preceding the potential biomedical application of nanoparticles is the evaluation of their immunomodulatory effects. Such nanoparticles are expected to enter the bloodstream where they can be recognized and processed by circulating monocytes. Despite the required biocompatibility, this interaction can affect intracellular homeostasis and modulate physiological functions, particularly inflammation. This study focuses on titanium dioxide (TiO2) as an example of relatively low cytotoxic nanoparticles with potential biomedical use and aims to evaluate their possible modulatory effects on the inflammasome-based response in human primary monocytes. METHODS: Monocyte viability, phenotypic changes, and cytokine production were determined after exposure to TiO2 (diameter, 25 nm; P25) alone. In the case of the modulatory effects, we focused on NLRP3 activation. The production of IL-1β and IL-10 was evaluated after (a) simultaneous activation of monocytes with bacterial stimuli muramyl dipeptide (MDP), or lipopolysaccharide (LPS), and TiO2 (co-exposure model), (b) prior activation with TiO2 alone and subsequent exposure to bacterial stimuli MDP or LPS. The differentiation of TiO2-treated monocytes into macrophages and their polarization were also assessed. RESULTS: The selected TiO2 concentration range (30-120 µg/mL) did not induce any significant cytotoxic effects. The highest dose of TiO2 promoted monocyte survival and differentiation into macrophages, with the M2 subset being the most prevalent. Nanoparticles alone did not induce substantial production of inflammatory cytokines IL-1β, IL-6, or TNF-α. The immunomodulatory effect on NLRP3 depended on the type of costimulant used. While co-exposure of monocytes to MDP and TiO2 boosted NLRP3 activity, co-exposure to LPS and TiO2 inhibited NLRP3 by enhancing IL-10 release. The inhibitory effect of TiO2 on NLRP3 based on the promotion of IL-10 was confirmed in a post-exposure model for both costimulants. CONCLUSION: This study confirmed a non-negligible modulatory effect on primary monocytes in their inflammasome-based response and differentiation ability.

• Klíčová slova
• NLRP3, TiO2 nanoparticles, immunomodulation, macrophages, monocytes, polarization,
• MeSH
• acetylmuramyl-alanyl-isoglutamin farmakologie   MeSH
• buněčná diferenciace účinky léků   MeSH
• cytokiny metabolismus   MeSH
• inflamasomy účinky léků   MeSH
• interleukin-10 metabolismus   MeSH
• interleukin-1beta metabolismus   MeSH
• kovové nanočástice chemie   toxicita   MeSH
• kultivované buňky MeSH
• lidé MeSH
• lipopolysacharidy * farmakologie   MeSH
• makrofágy účinky léků   MeSH
• monocyty * účinky léků   MeSH
• nanočástice chemie   toxicita   MeSH
• protein NLRP3 * metabolismus   MeSH
• titan * chemie   farmakologie   toxicita   MeSH
• viabilita buněk * účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetylmuramyl-alanyl-isoglutamin MeSH
• cytokiny MeSH
• inflamasomy MeSH
• interleukin-10 MeSH
• interleukin-1beta MeSH
• lipopolysacharidy * MeSH
• NLRP3 protein, human MeSH Prohlížeč
• protein NLRP3 * MeSH
• titan * MeSH
• titanium dioxide MeSH Prohlížeč

The utilization of nanomaterials in biomedical applications has surged in recent years; yet, the transition from research to practical implementation remains a great challenge. However, a promising area of research has emerged with the integration of nanomaterials with diagnostic and therapeutic radionuclides. In this Review, we elucidate the motivations behind selecting metal oxide- and phosphate-based nanomaterials in conjunction with these radionuclides, while addressing its issues and limitations. Various metal oxide- and phosphate-based nanoparticles, exhibiting low toxicity and high tolerability, have been proposed for diverse biomedical applications, ranging from bone substitutes to drug delivery systems and controlled release vectors for pharmaceuticals, including radionuclides for nuclear medicine imaging and therapy. Moreover, the potential synergistic effects of multimodal combinational therapies, integrating chemotherapeutics, immunomodulators, or hyperthermia, underscore the versatility of these nanoconstructs. Our comprehensive exploration includes the underlying principles of radiolabeling strategies, the pivotal attributes of nanomaterial platforms, and their applications. Through this perspective, we present the potential of nanotechnology-enabled nuclear medicine. Furthermore, we discuss the potential systemic and local applications of these nanoconstructs, considering their in vitro and in vivo characteristics, as well as their physicochemical properties.

• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

This review provides a detailed exploration of titanium dioxide (TiO2) photocatalysts, emphasizing structural phases, heterophase junctions, and their impact on efficiency. Key points include diverse synthesis methods, with a focus on the sol-gel route and variants like low-temperature hydrothermal synthesis (LTHT). The review delves into the influence of acid-base donors on gelation, dissects crucial drying techniques for TiO2 aerogel or xerogel catalysts, and meticulously examines mechanisms underlying photocatalytic activity. It highlights the role of physicochemical properties in charge diffusion, carrier recombination, and the impact of scavengers in photo-oxidation/reduction. Additionally, TiO2 doping techniques and heterostructures and their potential for enhancing efficiency are briefly discussed, all within the context of environmental applications.

• Klíčová slova
• TiO2, anatase, brookite, heterojunctions, photocatalysis, sol-gel synthesis,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

High-quality upconverting NaYF4:Yb3+,Er3+ nanoparticles (UCNPs; 26 nm in diameter) based on lanthanides were synthesized by a high-temperature coprecipitation method. The particles were modified by bisphosphonate-terminated poly(ethylene glycol) (PEG) and Rose Bengal (RB) photosensitizer. The particles were thoroughly characterized using transmission electron microscopy, dynamic light scattering, thermogravimetric analysis, FTIR, and X-ray photoelectron and upconversion luminescence spectroscopy in terms of morphology, hydrodynamic size, composition, and energy transfer to the photosensitizer. Moreover, the singlet oxygen generation from RB-containing UCNPs was investigated using 9,10-diphenylanthracene probe under 980 nm excitation. The cytotoxicity of UCNPs before and after conjugation with RB was evaluated on highly sensitive rat mesenchymal stem cells (rMSCs) and significant differences were found. Correspondingly, consi-derable variations in viability were revealed between the irradiated and non-irradiated rat glioma cell line (C6) exposed to RB-conjugated UCNPs. While the viability of rMSCs was not affected by the presence of UCNPs themselves, the cancer C6 cells were killed after the irradiation at 980 nm due to the reactive oxygen species (ROS) production, thus suggesting the potential of RB-conjugated PEG-modified UCNPs for applications in photodynamic therapy of cancer.

• Klíčová slova
• Rose Bengal, cytotoxicity, nanoparticles, photodynamic therapy, reactive oxygen species, upconverting,
• Publikační typ
• časopisecké články MeSH

The growing application of materials containing TiO2 particles has led to an increased risk of human exposure, while a gap in knowledge about the possible adverse effects of TiO2 still exists. In this work, TiO2 particles of rutile, anatase, and their commercial mixture were exposed to various environments, including simulated gastric fluids and human blood plasma (both representing in vivo conditions), and media used in in vitro experiments. Simulated body fluids of different compositions, ionic strengths, and pH were used, and the impact of the absence or presence of chosen enzymes was investigated. The physicochemical properties and agglomeration of TiO2 in these media were determined. The time dependent agglomeration of TiO2 related to the type of TiO2, and mainly to the type and composition of the environment that was observed. The presence of enzymes either prevented or promoted TiO2 agglomeration. TiO2 was also observed to exhibit concentration-dependent cytotoxicity. This knowledge about TiO2 behavior in all the abovementioned environments is critical when TiO2 safety is considered, especially with respect to the significant impact of the presence of proteins and size-related cytotoxicity.

• Klíčová slova
• TiO2 particles, agglomeration, plasma, proteins, simulated gastric fluids,
• MeSH
• buněčné linie MeSH
• dárci krve MeSH
• fibroblasty účinky léků   metabolismus   MeSH
• koncentrace vodíkových iontů MeSH
• kovové nanočástice škodlivé účinky   chemie   MeSH
• krevní plazma metabolismus   MeSH
• krystalizace MeSH
• kultivační média metabolismus   MeSH
• lidé MeSH
• myši MeSH
• osmolární koncentrace MeSH
• povrchové vlastnosti MeSH
• sliny metabolismus   MeSH
• titan škodlivé účinky   chemie   metabolismus   MeSH
• velikost částic MeSH
• viabilita buněk účinky léků   MeSH
• voda metabolismus   MeSH
• zdraví dobrovolníci pro lékařské studie MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kultivační média MeSH
• titan MeSH
• titanium dioxide MeSH Prohlížeč
• voda MeSH