High-Affinity-Mediated Viral Entry Triggers Innate Affinity Escape Resulting in Type I IFN Resistance and Impaired T Cell Immunity.

Increased receptor binding affinity may allow viruses to escape from Ab-mediated inhibition. However, how high-affinity receptor binding affects innate immune escape and T cell function is poorly understood. In this study, we used the lymphocytic choriomeningitis virus (LCMV) murine infection model system to create a mutated LCMV exhibiting higher affinity for the entry receptor α-dystroglycan (LCMV-GPH155Y). We show that high-affinity receptor binding results in increased viral entry, which is associated with type I IFN (IFN-I) resistance, whereas initial innate immune activation was not impaired during high-affinity virus infection in mice. Consequently, IFN-I resistance led to defective antiviral T cell immunity, reduced type II IFN, and prolonged viral replication in this murine model system. Taken together, we show that high-affinity receptor binding of viruses can trigger innate affinity escape including resistance to IFN-I resulting in prolonged viral replication.

Nanoparticles for Directed Immunomodulation: Mannose-Functionalized Glycodendrimers Induce Interleukin-8 in Myeloid Cell Lines.

New therapeutic strategies for personalized medicine need to involve innovative pharmaceutical tools, for example, modular nanoparticles designed for direct immunomodulatory properties. We synthesized mannose-functionalized poly(propyleneimine) glycodendrimers with a novel architecture, where freely accessible mannose moieties are presented on poly(ethylene glycol)-based linkers embedded within an open-shell maltose coating. This design enhanced glycodendrimer bioactivity and led to complex functional effects in myeloid cells, with specific induction of interleukin-8 expression by mannose glycodendrimers detected in HL-60 and THP-1 cells. We concentrated on explaining the molecular mechanism of this phenomenon, which turned out to be different in both investigated cell lines: in HL-60 cells, transcriptional activation via AP-1 binding to the promoter predominated, while in THP-1 cells (which initially expressed less IL-8), induction was mediated mainly by mRNA stabilization. The success of directed immunomodulation, with synthetic design guided by assumptions about mannose-modified dendrimers as exogenous regulators of pro-inflammatory chemokine levels, opens new possibilities for designing bioactive nanoparticles.

Physicochemical and in vitro cytotoxicity studies of inclusion complex between gemcitabine and cucurbit[7]uril host.

Gemcitabine, a cytostatic drug from the pyrimidine antimetabolite group, exhibits limited storage stability and numerous side effects during therapy. One of the strategies to improve the effectiveness of therapy with such drugs is the use of supramolecular nano-containers, including dendrimers and macrocyclic compounds. The ability of gemcitabine to attach a proton in an aqueous environment necessitates the search for a carrier that is well-tolerated by an organism and capable of supramolecular binding of a ligand (drug) in a cationic form. In the current study a promising strategy was tested for using cucurbituril Q7 to bind gemcitabine cations for its efficient intracellular delivery on three selected cancer cell lines (MOLT4, THP-1 and U937). Based on physicochemical studies (equilibrium dialysis, UV and 1H NMR titrations, DOSY 1H NMR measurements, DSC calorimetry) and cytotoxicity tests on cells with a free and blocked hENT1 transporter, the conclusion was drawn about the binding and penetration of the cucurbituril-drug complex into cancer cells.

Application of new lysine-based peptide dendrimers D3K2 and D3G2 for gene delivery: Specific cytotoxicity to cancer cells and transfection in vitro.

In order to enhance intracellular uptake and accumulation of therapeutic nucleic acids for improved gene therapy methods, numerous delivery vectors have been elaborated. Based on their origin, gene carriers are generally classified as viral or non-viral vectors. Due to their significantly reduced immunogenicity and highly optimized methods of synthesis, nanoparticles (especially those imitating natural biomolecules) constitute a promising alternative for virus-based delivery devices. Thus, we set out to develop innovative peptide dendrimers for clinical application as transfection agents and gene carriers. In the present work we describe the synthesis of two novel lysine-based dendritic macromolecules (D3K2 and D3G2) and their initial characterization for cytotoxicity/genotoxicity and transfection potential in two human cell line models: cervix adenocarcinoma (HeLa) and microvascular endothelial (HMEC-1). This approach allowed us to identify more cationic D3K2 as potent delivery agent, being able to increase intracellular accumulation of large nucleic acid molecules such as plasmids. Moreover, the dendrimers exhibited specific cytotoxicity towards cancer cell line without showing significant toxic effects on normal cells. These observations are promising prognosis for future clinical application of this type of nanoparticles.

In Search of a Phosphorus Dendrimer-Based Carrier of Rose Bengal: Tyramine Linker Limits Fluorescent and Phototoxic Properties of a Photosensitizer.

Photodynamic therapy (PDT) is a skin cancer treatment alternative to chemotherapy and radiotherapy. This method exploits three elements: a phototoxic compound (photosensitizer), light source and oxygen. Upon irradiation by light of a specific wavelength, the photosensitizer generates reactive oxygen species triggering the cascade of reactions leading to cell death. The positive therapeutic effect of PDT may be limited due to low solubility, low tumor specificity and inefficient cellular uptake of photosensitizers. A promising approach to overcome these obstacles involves the use of nanocarrier systems. The aim of this initial study was to determine the potential of the application of phosphorus dendrimers as carriers of a photosensitizer-rose bengal (RB). The primary goal involved the synthesis and in vitro studies of covalent drug-dendrimer conjugates. Our approach allowed us to obtain RB-dendrimer conjugates with the use of tyramine as an aromatic linker between the carrier and the drug. The compounds were characterized by FT-IR, 1H NMR, 13C NMR, 31P NMR, size and zeta potential measurements and spectrofluorimetric analysis. The dialysis to check the drug release from the conjugate, flow cytometry to specify intracellular uptake, and singlet oxygen generation assay were also applied. Finally, we used MTT assay to determine the biological activity of the tested compounds. The results of our experiments indicate that the conjugation of RB to phosphorus dendrimers via the tyramine linker decreases photodynamic activity of RB.

Poly(lysine) Dendrimers Form Complexes with siRNA and Provide Its Efficient Uptake by Myeloid Cells: Model Studies for Therapeutic Nucleic Acid Delivery.

The disruption of the cellular pathways of protein biosynthesis through the mechanism of RNA interference has been recognized as a tool of great diagnostic and therapeutic significance. However, in order to fully exploit the potential of this phenomenon, efficient and safe carriers capable of overcoming extra- and intracellular barriers and delivering siRNA to the target cells are needed. Recently, attention has focused on the possibility of the application of multifunctional nanoparticles, dendrimers, as potential delivery devices for siRNA. The aim of the present work was to evaluate the formation of dendriplexes using novel poly(lysine) dendrimers (containing lysine and arginine or histidine residues in their structure), and to verify the hypothesis that the use of these polymers may allow an efficient method of siRNA transfer into the cells in vitro to be obtained. The fluorescence polarization studies, as well as zeta potential and hydrodynamic diameter measurements were used to characterize the dendrimer:siRNA complexes. The cytotoxicity of dendrimers and dendriplexes was evaluated with the resazurin-based assay. Using the flow cytometry technique, the efficiency of siRNA transport to the myeloid cells was determined. This approach allowed us to determine the properties and optimal molar ratios of dendrimer:siRNA complexes, as well as to demonstrate that poly(lysine) dendrimers may serve as efficient carriers of genetic material, being much more effective than the commercially available transfection agent Lipofectamine 2000. This outcome provides the basis for further research on the application of poly(lysine) dendrimers as carriers for nucleic acids in the field of gene therapy.

Silver Nanoparticles Surface-Modified with Carbosilane Dendrons as Carriers of Anticancer siRNA.

Gene therapy is a promising approach in cancer treatment; however, current methods have a number of limitations mainly due to the difficulty in delivering therapeutic nucleic acids to their sites of action. The application of non-viral carriers based on nanomaterials aims at protecting genetic material from degradation and enabling its effective intracellular transport. We proposed the use of silver nanoparticles (AgNPs) surface-modified with carbosilane dendrons as carriers of anticancer siRNA (siBcl-xl). Using gel electrophoresis, zeta potential and hydrodynamic diameter measurements, as well as transmission electron microscopy, we characterized AgNP:siRNA complexes and demonstrated the stability of nucleic acid in complexes in the presence of RNase. Hemolytic properties of free silver nanoparticles and complexes, their effect on lymphocyte proliferation and cytotoxic activity on HeLa cells were also examined. Confocal microscopy proved the effective cellular uptake of complexes, indicating the possible use of this type of silver nanoparticles as carriers of genetic material in gene therapy.

Gold Nanoparticles in Cancer Treatment.

Colloidal gold has been studied for its potential application in medicine for centuries. However, synthesis and evaluation of various gold nanoparticles have only recently been met with a wide interest of scientists. Current studies confirm numerous advantages of nanogold over different nanomaterials, primarily due to highly optimized protocols for the production of gold nanoparticles of countless sizes and shapes, featured with unique properties. The possibility to modify the surface of nanogold particles with different targeting and functional compounds significantly broadens the range of their potential biomedical applications, with particular emphasis on cancer treatment. Functionalized gold nanoparticles exhibit good biocompatibility and controllable biodistribution patterns, which make them particularly fine candidates for the basis of innovative therapies. Considering the high amount of scientific data on nanogold, this review summarizes recent advances in the field of medical application of gold nanoparticles for the therapy of cancer.

Fludarabine-Specific Molecular Interactions with Maltose-Modified Poly(propyleneimine) Dendrimer Enable Effective Cell Entry of the Active Drug Form: Comparison with Clofarabine.

Fludarabine is an anticancer antimetabolite essential for modern chemotherapy, but its efficacy is limited due to the complex pharmacokinetics. We demonstrated the potential use of maltose-modified poly(propyleneimine) dendrimer as drug delivery agent to improve the efficiency of therapy with fludarabine. In this study, we elaborated a novel synthesis technique for radioactively labeled fludarabine triphosphate to prove for the first time the direct ability of nucleotide-glycodendrimer complex to enter and kill leukemic cells, without the involvement of membrane nucleoside transporters and intracellular kinases. This will potentially allow to bypass the most common drug resistance mechanisms observed in the clinical setting. Further, we applied surface plasmon resonance and molecular modeling to elucidate the properties of the drug-dendrimer complexes. We showed that clofarabine, a more toxic nucleoside analogue drug, is characterized by significantly different molecular interactions with poly(propyleneimine) dendrimers than fludarabine, leading to different cellular outcomes (decreased rather than increased treatment efficiency). The most probable mechanistic explanation of uniquely dendrimer-enhanced fludarabine toxicity points to a crucial role of both an alternative cellular uptake pathway and the avoidance of intracellular phosphorylation of nucleoside drug form.

Sugar Modification Enhances Cytotoxic Activity of PAMAM-Doxorubicin Conjugate in Glucose-Deprived MCF-7 Cells - Possible Role of GLUT1 Transporter.

PURPOSE: In order to overcome the obstacles and side effects of classical chemotherapy, numerous studies have been performed to develop the treatment based on targeted transport of active compounds directly to the site of action. Since tumor cells are featured with intensified glucose metabolism, we set out to develop innovative, glucose-modified PAMAM dendrimer for the delivery of doxorubicin to breast cancer cells. METHODS: PAMAM-dox-glc conjugate was synthesized and characterized by 1H NMR, FT-IR, size and zeta potential measurements. The drug release rate from conjugate was evaluated by dialysis under different pH conditions. The expression level of GLUT family receptors in cells cultured in full and glucose-deprived medium was evaluated by quantitative real-time RT-PCR and flow cytometry. The cytotoxicity of conjugate in presence or absence of GLUT1 inhibitors was determined by MTT assay. RESULTS: We showed that PAMAM-dox-glc conjugate exhibits pH-dependent drug release and increased cytotoxic activity compared to free drug in cells cultured in medium without glucose. Further, we proved that these cells overexpress transporters of GLUT family. The toxic effect of conjugate was eliminated by the application of specific GLUT1 inhibitors. CONCLUSION: Our findings revealed that the glucose moiety plays a crucial role in the recognition of cells with high expression of GLUT receptors. By selectively blocking GLUT1 transporter we showed its importance for the cytotoxic activity of PAMAM-dox-glc conjugate. These results suggest that PAMAM-glucose formulations may constitute an efficient platform for the specific delivery of anticancer drugs to tumor cells overexpressing transporters of GLUT family.

Effect of the Structure of Therapeutic Adenosine Analogues on Stability and Surface Electrostatic Potential of their Complexes with Poly(propyleneimine) Dendrimers.

Poly(propyleneimine) glycodendrimers are proposed as nanocarriers for triphosphate forms of anticancer adenosine analogues to improve the efficiency of chemotherapy and to overcome drug resistance mechanisms. This approach has proven successful for fludarabine administration-an autonomous way of cellular entry of a nucleotide-dendrimer noncovalent complex enables an increase in the intracellular accumulation and cytotoxic activity of the active metabolite of the drug. However, the attempt to apply an analogous strategy for clofarabine results in the inhibition of drug activity. To better understand this phenomenon, characterization and comparison of drug-dendrimer complexes were needed to indicate the differences in their surface properties and the strengths of fludarabine-dendrimer and clofarabine-dendrimer interactions. Here, zeta potential measurements, ultrafiltration, and asymmetric flow field-flow fractionation are applied to determine the surface electrostatic potential and stability of nucleotide-dendrimer formulations. This approach significantly extends the authors' research on the complexation potential of perfectly branched macromolecules, ultimately explaining previously observed differences and their consequences.

Complexes of Indomethacin with 4-Carbomethoxy-pyrrolidone PAMAM Dendrimers Show Improved Anti-inflammatory Properties and Temperature-Dependent Binding and Release Profile.

COX-2 inhibitors such as nonsteroidal anti-inflammatory drugs (NSAIDs) are the most common treatment for chronic inflammatory diseases like arthritis and atherosclerosis. However, they are associated with severe side effects such as cardiovascular events or stomach bleeding, due to coinhibition of other enzymes (COX1) and off-target accumulation. PAMAM dendrimers can solubilize lipophilic drugs and increase their circulation time; furthermore, PAMAM dendrimers seem to have some accumulation in inflammatory sides. Three different generations of 4-carbomethoxypyrrolidone (Pyr) surface-modified PAMAM dendrimers were complexed with the NSAID drug indomethacin, and their in-solution thermodynamic profiles were studied by means of NMR experiments. The binding stoichiometry was found dependent on solvent system and dendrimer generation. Larger dendrimers (G3-Pyr) were found to bind indomethacin through entropy driven binding mode, while G1-Pyr and G2-Pyr expressed an enthalpy driven complex formation, which means that the binding constants have a generational temperature dependency. G1/2-Pyr showed reduced binding with increasing temperature, which could be important for drug release at inflammatory sites, which have, in general, elevated temperatures. In vitro studies elucidated that the indomethacin drug remained its activity when delivered as a dendrimer-indomethacin complex. A slight reduction in toxicity profile was noticed for G2/G3-Pyr-indomethacin dendrimers. Both free indomethacin and dendrimer-indomethacin complex inhibited a variety of pro-inflammatory cytokines in LPS treated cells. However, only the indo-dendrimer complexes showed a significant reduction of IL-1ß in LPS-treated THP-1 cells, which was not present in the control with free indomethacin.

Pyrrolidone Modification Prevents PAMAM Dendrimers from Activation of Pro-Inflammatory Signaling Pathways in Human Monocytes.

The biological features of dendrimers are affected by the character of highly reactive terminal moieties. In some polyamine dendrimer types the surface charge makes them bioincompatible and prevent their direct medical application. Moreover, foreign particles can induce the immune response which is undesirable due to the adverse side effects in vivo. The reduction of cytotoxicity of positively charged macromolecules is possible through chemical modifications of terminal groups. In our study, we have developed new derivatives of PAMAM dendrimers modified with 4-carbomethoxypyrrolidone and evaluated their immunomodulatory properties. The experiments were conducted on two human cancer myeloid cell lines: THP-1 and U937. To evaluate the cytotoxicity of dendrimers, the reasazurin assay was applied. The expression level of NF-κB targets (NFKBIA, BTG2) and cytokine genes (IL1B, TNF) was determined by quantitative real-time RT-PCR. The measurement of binding of NF-κB to a consensus DNA probe was determined by electrophoretic mobility shift assay. The ELISA cytokine assay was performed to measure protein concentration of IL-1ß and TNFα. We have found that PAMAM-pyrrolidone dendrimers did not impact THP-1 and U937 viability even at high concentrations (up to 200 µM). The surface modification prevented PAMAM dendrimers from stimulating NF-κB-related signal transduction, which have been determined on the level of nuclear translocation, gene expression and protein secretion. Pyrrolidone modification efficiently prevents PAMAM dendrimers from stimulating pro-inflammatory response in human cancer myeloid cell lines, thus it can be used to improve the biocompatibility of positively charged dendrimers and to broaden the scope of their biological applications.

Terminal Sugar Moiety Determines Immunomodulatory Properties of Poly(propyleneimine) Glycodendrimers.

Poly(propyleneimine) dendrimers fully surface-modified with disaccharide moieties (maltose, cellobiose, and lactose) designed to mimic natural lectin receptor ligands were tested for their bioactivity in two myeloid cell lines: THP-1 and HL-60. Depending on the sugar modification, we observed variable activation of NF-κB, AP-1, and NF-AT signaling pathways: lactose-coated dendrimers had the strongest impact on marker gene expression and most signaling events with the notable exception of NF-κB activation in THP-1 cells. The two cell lines showed an overall similar pattern of transcription factor and gene expression activation upon treatment with glycodendrimers, suggesting the involvement of galectin and C-type lectin receptor types. An important result of this action was the overexpression of CD40 and IL8 genes, potentially leading to an activated, proinflammatory phenotype in the monocyte/macrophage cell lineage. These pharmacodynamic characteristics of glycodendrimers need to be taken into account during their pharmaceutical applications both in drug delivery and direct immunomodulation.

Glycodendrimer Nanocarriers for Direct Delivery of Fludarabine Triphosphate to Leukemic Cells: Improved Pharmacokinetics and Pharmacodynamics of Fludarabine.

Fludarabine, a nucleoside analogue antimetabolite, has complicated pharmacokinetics requiring facilitated transmembrane transport and intracellular conversion to triphosphate nucleotide form (Ara-FATP), causing it to be susceptible to emergence of drug resistance. We are testing a promising strategy to improve its clinical efficacy by direct delivery of Ara-FATP utilizing a biocompatible glycodendrimer nanocarrier system. Here, we present results of a proof-of-concept experiment in several in vitro-cultured leukemic cell lines (CCRF, THP-1, U937) using noncovalent complexes of maltose-modified poly(propyleneimine) dendrimer and fludarabine triphosphate. We show that Ara-FATP has limited cytotoxic activity toward investigated cells relative to free nucleoside (Ara-FA), but complexation with the glycodendrimer (which does not otherwise influence cellular metabolism) drastically increases its toxicity. Moreover, we show that transport via hENT1 is a limiting step in Ara-FA toxicity, while complexation with dendrimer allows Ara-FATP to kill cells even in the presence of a hENT1 inhibitor. Thus, the use of glycodendrimers for drug delivery would allow us to circumvent naturally occurring drug resistance due to decreased transporter activity. Finally, we demonstrate that complex formation does not change the advantageous multifactorial intracellular pharmacodynamics of Ara-FATP, preserving its high capability to inhibit DNA and RNA synthesis and induce apoptosis via the intrinsic pathway. In comparison to other nucleoside analogue drugs, fludarabine is hereby demonstrated to be an optimal candidate for maltose glycodendrimer-mediated drug delivery in antileukemic therapy.

Sugar-Modified Poly(propylene imine) Dendrimers Stimulate the NF-κB Pathway in a Myeloid Cell Line.

PURPOSE: Fourth-generation poly(propylene imine) dendrimers fully surface-modified by maltose (dense shell, PPI-m DS) were shown to be biocompatible in cellular models, which is important for their application in drug delivery. We decided to verify also their inherent bioactivity, including immunomodulatory activity, for potential clinical applications. We tested their effects on the THP-1 monocytic cell line model of innate immunity effectors. METHODS: To estimate the cytotoxicity of dendrimers the reasazurin assay was performed. The expression level of NF-κB targets: IGFBP3, TNFAIP3 and TNF was determined by quantitative real-time RT-PCR. Measurement of NF-κB p65 translocation from cytoplasm to nucleus was conducted with a high-content screening platform and binding of NF-κB to a consensus DNA probe was determined by electrophoretic mobility shift assay. The cytokine assay was performed to measure protein concentration of TNFalpha and IL-4. RESULTS: We found that PPI-m DS did not impact THP-1 viability and growth even at high concentrations (up to 100 µM). They also did not induce expression of genes for important signaling pathways: Jak/STAT, Keap1/Nrf2 and ER stress. However, high concentrations of 4th generation PPI-m DS (25-100 µM), but not their 3rd generation counterparts, induced nuclear translocation of p65 NF-κB protein and its DNA-binding activity, leading to NF-κB-dependent increased expression of mRNA for NF-κB targets: IGFBP3, TNFAIP3 and TNF. However, no increase in pro-inflammatory cytokine secretion was detected. CONCLUSION: We conclude that maltose-modified PPI dendrimers of specific size could exert a modest immunomodulatory effect, which may be advantageous in clinical applications (e.g. adjuvant effect in anti-cancer vaccines).

The role of glycosylation patterns of viral glycoproteins and cell entry receptors in arenavirus infection.

Mammarenaviruses are enveloped RNA viruses that can be associated with rodent-transmitted diseases in humans. Their virions are composed of a nucleocapsid surrounded by a lipid bilayer with glycoprotein (GP) spikes interacting with receptors on target cells. Both the GP and receptors are highly glycosylated, with glycosylation patterns being crucial for virus binding and cell entry, viral tropism, immune responses, or therapy strategies. These effects have been previously described for several different viruses. In case of arenaviruses, they remain insufficiently understood. Thus, it is important to determine the mechanisms of glycosylation of viral proteins and receptors responsible for infection, in order to fully understand the biology of arenaviruses. In this article, we have summarized and critically evaluated the available literature data on the glycosylation of mammarenavirus-associated proteins to facilitate further research in this field.

Mesalazine-PAMAM Nanoparticles for Transporter-Independent Intracellular Drug Delivery: Cellular Uptake and Anti-Inflammatory Activity.

Background: Mesalazine is one of the main drugs used to treat inflammatory bowel diseases. However, its applicability is limited by its rapid inactivation and removal from the organism, as well as the need for its membrane transporter-dependent cellular uptake to exert therapeutic effect. The present study involved the development of an innovative nanocarrier, based on poly(amidoamine) (PAMAM) dendrimer of the 4th generation, to obtain higher concentrations of the drug in the intestinal epithelial cells, thus increasing its anti-inflammatory potential. The work involved synthesis and in vitro characterization of covalent PAMAM-mesalazine conjugate with succinic linker. Results: PAMAM-mesalazine conjugate was synthesized and characterized by 1H NMR, 13C NMR, FTIR and MALDI-TOF MS. This allowed to confirm the purity of the obtained compound and intermediates. Based on the analyses, it was found that ~45 drug molecules were successfully attached to one molecule of PAMAM dendrimer. The conjugate was then characterized in terms of hydrodynamic diameter, zeta potential, spectral properties, drug release from the carrier, as well as cellular uptake and cytotoxicity in two in vitro models of gastrointestinal epithelium (CaCo-2 and HT-29 human cell lines). Analyzing cellular parameters related to the specific mechanism of action of mesalazine (inhibition of NF-κB signaling, decrease in interleukin and prostaglandin synthesis, and ROS scavenging), we showed that such a dendrimer-based carrier may enhance cellular uptake of the drug, which translated into its improved anti-inflammatory efficacy. Conclusion: The use of PAMAM macromolecule as a carrier for mesalazine increases the bioavailability of the drug, ensuring enhanced cellular uptake and bypassing the need to utilize mesalazine-specific membrane transporters. All these characteristics translate into an improved anti-inflammatory activity of mesalazine in vitro. In conjunction with appropriately designed in vivo studies, such a compound may prove to be a promising alternative to the therapeutics currently used in inflammatory bowel diseases.

The effect of surface modification of dendronized gold nanoparticles on activation and release of pyroptosis-inducing pro-inflammatory cytokines in presence of bacterial lipopolysaccharide in monocytes.

Biomedical applications of gold nanoparticles (AuNPs) may be limited by their toxicological effects. Although surface-modified AuNPs can induce apoptosis, less is known about whether they can induce other types of cell death. Pyroptosis, an inflammatory type of programmed cell death, can be induced in immune cells, especially macrophages, by bacterial endotoxins. Therefore, in this study, dendronized AuNPs were combined with bacterial lipopolysaccharides (LPSs) as the main stimulators of pro-inflammatory responses to test the induction of pyroptosis in THP-1 myeloid cell line. These AuNPs induced caspase-1 activity (3-4 times more compared to control) and enhanced the release of interleukin (IL)-18 and IL-1ß without inducing gasdermin D cleavage and related pore formation. The production of pro-inflammatory cytokines occurred mainly visible during LPS treatment, although their secretion was observed only after administration of dendronized AuNPs (release of IL-1ß to supernatant up to 80 pg/mL). These findings suggest that dendronized AuNPs can induce pyroptosis-like inflammatory mechanisms and that these mechanisms are enhanced in the presence of bacterial LPS. The intensity of this effect was dependent on AuNP surface modification. These results shed new light on the cytotoxicity of metal NPs, including immune responses, indicating that surface modifications play crucial roles in their nanotoxicological effects.

Triazine-Carbosilane Dendrimersomes Enhance Cellular Uptake and Phototoxic Activity of Rose Bengal in Basal Cell Skin Carcinoma Cells.

Background: The search for new formulations for photodynamic therapy is intended to improve the outcome of skin cancer treatment using significantly reduced doses of photosensitizer, thereby avoiding side effects. The incorporation of photosensitizers into nanoassemblies is a versatile way to increase the efficiency and specificity of drug delivery into target cells. Herein, we report the loading of rose bengal into vesicle-like constructs of amphiphilic triazine-carbosilane dendrons (dendrimersomes) as well as biophysical and in vitro characterization of this novel nanosystem. Methods: Using established protocol and analytical and spectroscopy techniques we were able to synthesized dendrons with strictly designed properties. Engaging biophysical methods (hydrodynamic diameter and zeta potential measurements, analysis of spectral properties, transmission electron microscopy) we confirmed assembling of our nanosystem. A set of in vitro techniques was used for determination ROS generation, (ABDA and H2DCFDA probes), cell viability (MTT assay) and cellular uptake (flow cytometry and confocal microscopy). Results: Encapsulation of rose bengal inside dendrimersomes enhances cellular uptake, intracellular ROS production and concequently, the phototoxicity of this photosensitizer. Conclusion: Triazine-carbosilane dendrimersomes show high capacity as drug carriers for anticancer photodynamic therapy.