Effectiveness of Rhenium(I)-diselenoether Low Doses in a Triple-negative Breast Cancer Chicken Embryo Model.

BACKGROUND/AIM: Rhenium(I)-diselenoether (Re-diSe) is a promising anticancer agent composed of one rhenium and two selenium atoms. Its effectiveness was established in inhibiting cancer cells while maintaining low toxicity toward normal cells at a 5 µM dose for 120 hours in MDA-MB-231 cells. In MDA-MB-231 breast tumor-bearing mice, anti-tumor and anti-metastatic effects were observed at a 10 mg/kg dose. However, contradictory results were observed in the 4T1 breast cancer model, where a dose of 60 mg/kg had a pro-tumor effect. To address these discrepancies, the efficacy of Re-diSe at the effective 10 mg/kg dose was validated in a transplanted MDA-MB-231 breast tumor model using the chicken chorioallantoic membrane assay. MATERIALS AND METHODS: MDA-MB-231 cancer cells were xenografted onto the chicken chorioallantoic membrane (CAM), and daily drug administration was carried out for nine days at doses of 0.1, 1, and 10 mg/kg. At the study's conclusion, a standard histological analysis was conducted. RESULTS: The low dose of 0.1 mg/kg showed a significant reduction in tumor weights compared to controls. The 1 mg/kg dose resulted in an increased inflammation score but did not induce a significant difference in tumor weights compared to the 0.1 mg/kg dose. Notably, at the 10 mg/kg dose, six out of 11 treated embryos displayed no visible signs of tumors. These tumors exhibited extensive tumor necrosis and significant infiltration by inflammatory cells. CONCLUSION: In this particular model, the anticancer efficacy of Re-diSe was achieved at the low dose of 0.1 mg/kg. The higher dose of 10 mg/kg, while eliminating visible tumors, might have immune-mediated effects, as indicated by substantial tumor necrosis and infiltration by inflammatory cells. Overall, this study successfully demonstrated the effectiveness of Re-diSe as an anticancer agent.

Remarkable Effects of a Rhenium(I)-diselenoether Drug on the Production of Cathepsins B and S by Macrophages and their Polarizations.

BACKGROUND/OBJECTIVE: Tumor-associated macrophages (TAMs) produce an excessive amount of cysteine proteases, and we aimed to study the effects of anticancer rhenium(I)-diselenoether (Re-diSe) on the production of cathepsins B and S by macrophages. We investigated the effect of Re-diSe on lipopolysaccharides (LPS) induced M1 macrophages, or by interleukin 6 (IL-6) induced M2 macrophages. METHODS: Non-stimulated or prestimulated murine Raw 264 or human THP-1 macrophages were exposed to increasing concentrations of the drug (5, 10, 20, 50 and 100 µM) and viability was assayed by the MTT assay. The amount of cysteine proteases was evaluated by ELISA tests, the number of M1 and M2 macrophages by the expression of CD80 or CD206 biomarkers. The binding of Re-diSe with GSH as a model thiol-containing protein was studied by mass spectrometry. RESULTS: A dose-dependent decrease in cathepsins B and S was observed in M1 macrophages. There was no effect in non-stimulated cells. The drug induced a dramatic dose-dependent increase in M1 expression in both cells, significantly decreased the M2 expression in Raw 264 and had no effect in non-stimulated macrophages. The binding of the Re atom with the thiols was clearly demonstrated. CONCLUSION: The increase in the number of M1 and a decrease in M2 macrophages treated by Re-diSe could be related to the decrease in cysteine proteases upon binding of their thiol residues with the Re atom.

Development and Characterization of Innovative Multidrug Nanoformulation for Cardiac Therapy.

For several decades, various peptides have been under investigation to prevent ischemia/reperfusion (I/R) injury, including cyclosporin A (CsA) and Elamipretide. Therapeutic peptides are currently gaining momentum as they have many advantages over small molecules, such as better selectivity and lower toxicity. However, their rapid degradation in the bloodstream is a major drawback that limits their clinical use, due to their low concentration at the site of action. To overcome these limitations, we have developed new bioconjugates of Elamipretide by covalent coupling with polyisoprenoid lipids, such as squalenic acid or solanesol, embedding self-assembling ability. The resulting bioconjugates were co-nanoprecipitated with CsA squalene bioconjugate to form Elamipretide decorated nanoparticles (NPs). The subsequent composite NPs were characterized with respect to mean diameter, zeta potential, and surface composition by Dynamic Light Scattering (DLS), Cryogenic Transmission Electron Microscopy (CryoTEM) and X-ray Photoelectron Spectrometry (XPS). Further, these multidrug NPs were found to have less than 20% cytotoxicity on two cardiac cell lines even at high concentrations, while maintaining an antioxidant capacity. These multidrug NPs could be considered for further investigations as an approach to target two important pathways involved in the development of cardiac I/R lesions.

Quantification of drug loading in polymeric nanoparticles using AFM-IR technique: a novel method to map and evaluate drug distribution in drug nanocarriers.

Researchers are increasingly thinking smaller to solve some of the biggest challenges in nanomedicine: the control of drug encapsulation. Although recent years have witnessed a significant increase in the development and characterization of polymeric drug nanocarriers, several key features are still to be addressed: Where is the drug located within each nanoparticle (NP)? How much drug does each NP contain? Is the drug loading homogeneous on an individual NP basis? To answer these questions, individual NP characterization was achieved here by using atomic force microscopy-infrared spectroscopy (AFM-IR). A label-free quantification methodology was proposed to estimate with a nanoscale resolution the drug loadings of individual poly(lactic acid) (PLA) NPs loaded with an anticancer drug. First, a drug loading calibration curve was established using conventional IR microspectroscopy employing PLA/drug homogeneous films of well-known compositions. Then, single NPs were investigated by AFM-IR acquiring both IR mappings of PLA and drug as well as local IR spectra. Besides, drug location within single NPs was unravelled. The measured drug loadings were drastically different (0 to 21 wt%) from one NP to another, emphasizing the particular interest of this methodology in providing a simple quantification method for the quality control of nanomedicines.

Degradation of Polymer-Drug Conjugate Nanoparticles Based on Lactic and Itaconic Acid.

Tuberculosis (TB) is still a significant threat to human health. A promising solution is engineering nanoparticulate drug carriers to deliver anti-TB molecules. Itaconic acid (ITA) potentially has anti-TB activity; however, its incorporation in nanoparticles (NP) is challenging. Here we show an approach for preparing polymer-ITA conjugate NPs and a methodology for investigating the NP degradation and ITA release mechanism. The conjugate was synthesized by the two-directional growing of polylactic acid (PLA) chains, followed by capping their extremities with ITA. The poly(lactate)-itaconate PLA-ITA was then used to formulate NPs. The degradation and drug release processes of the polymer conjugate NPs were studied qualitatively and quantitatively. The molecular structures of released species were characterized by using liquid NMR spectroscopy and mass spectrometry. We discovered a complex NP hydrolysis process forming diverse oligomers, as well as monomeric lactic acid (LA) and drug ITA. The slow degradation process led to a low release of free drugs, although raising the pH from 5.3 to 7.4 induced a slight increase in the amounts of released products. TEM images showed that bulk erosion is likely to play the primary role in the degradation of PLA-ITA NPs. The overall results and methodology can be of interest for understanding the mechanisms of NP degradation and drug release of this new polymer-drug conjugate system.

The NSP14/NSP10 RNA repair complex as a Pan-coronavirus therapeutic target.

The risk of zoonotic coronavirus spillover into the human population, as highlighted by the SARS-CoV-2 pandemic, demands the development of pan-coronavirus antivirals. The efficacy of existing antiviral ribonucleoside/ribonucleotide analogs, such as remdesivir, is decreased by the viral proofreading exonuclease NSP14-NSP10 complex. Here, using a novel assay and in silico modeling and screening, we identified NSP14-NSP10 inhibitors that increase remdesivir's potency. A model compound, sofalcone, both inhibits the exonuclease activity of SARS-CoV-2, SARS-CoV, and MERS-CoV in vitro, and synergistically enhances the antiviral effect of remdesivir, suppressing the replication of SARS-CoV-2 and the related human coronavirus OC43. The validation of top hits from our primary screenings using cellular systems provides proof-of-concept for the NSP14 complex as a therapeutic target.

Mannosylation of budesonide palmitate nanoprodrugs for improved macrophage targeting.

In a strategy to improve macrophage targeting of glucocorticoids (GCs) for anti-inflammatory therapy, a so-called nanoprodrug of budesonide palmitate decorated by mannose moieties was designed. The synthesis of budesonide palmitate (BP) was obtained by esterification and mannosylated lipid (DSPE-PEG-Man) by reacting 1,2-Distearoyl-sn-Glycero-3-Phosphoethanolamine (DSPE)-polyethylene glycol-amine and α-D-mannopyranosylphenyl isothiocyanate (MPITC). Nanoparticles were formulated by emulsion-evaporation and different ratios of mannosylated lipid were introduced in the formulation of BP nanoprodrugs. Using up to 75% of DSPE-PEG-man (75/25) led to 200 nm particles with a polydispersity index below 0.2, a negative zeta potential ranging from -10 to -30 mV, and one-month stability at 4 °C. The encapsulation efficiency of BP approached 100% proving that the prodrug was associated with the particles, leading to a final BP loading of 50-to 60% (w/w). The lectin agglutination test confirmed the availability of mannose on the nanoprodrug surface. Nanoprodrug uptake by RAW 264.7 macrophages was observed by confocal microscopy and flow cytometry. After 24 and 48 h of incubation, a significantly greater internalization of mannosylated nanoparticles as compared to PEGylated nanoparticles was achieved. The mannose receptor-mediated uptake was confirmed by a mannan inhibition study. After LPS-induced inflammation, the anti-inflammatory effect of mannosylated nanoparticles was assessed. After 48 h of incubation, cytokines (MCP-1 and TNFα) were reduced demonstrating that the functionalization of nanoprodrugs is possible and efficient.

Effects of Rhenium(I)-diselenoether and of its Diselenide Ligand on the Production of Cathepsins B and S by MDA-MB231 Breast Malignant Cells.

BACKGROUND/AIM: Rhenium(I)-diselenoether (Re-diSe) is a drug under development for the treatment of metastatic cancers, with selective inhibitory effects on MDA-MB231 cancer cells compared to normal HEK-293 cells, and with greater effects than its diselenide (di-Se) ligand. Rhenium (Re) compounds inhibit cathepsins, which are important proteolytic enzymes in cancer. This study investigated the effects of Re-diSe and di-Se on the production of cathepsins B and S in MDA-MB231 malignant and HEK-293 normal cells and their inhibitory effects following treatment with different doses for 72 h. MATERIALS AND METHODS: Elisa tests were used to assay the amount of cathepsins B and S in the medium of cultures. RESULTS: Re-diSe, but not diSe affected the viability of malignant cells and the expression of cathepsins B and S. CONCLUSION: To the best of our knowledge, this is the first demonstration that Re-diSe may decrease the production of cathepsins B and S in cancer cells at doses as low as 10 µM.

Decoration of Squalenoyl-Gemcitabine Nanoparticles with Squalenyl-Hydroxybisphosphonate for the Treatment of Bone Tumors.

Therapeutic perspectives of bone tumors such as osteosarcoma remain restricted due to the inefficacy of current treatments. We propose here the construction of a novel anticancer squalene-based nanomedicine with bone affinity and retention capacity. A squalenyl-hydroxybisphosphonate molecule was synthetized by chemical conjugation of a 1-hydroxyl-1,1-bisphosphonate moiety to the squalene chain. This amphiphilic compound was inserted onto squalenoyl-gemcitabine nanoparticles using the nanoprecipitation method. The co-assembly led to nanoconstructs of 75 nm, with different morphology and colloidal properties. The presence of squalenyl-hydroxybisphosphonate enhanced the nanoparticles binding affinity for hydroxyapatite, a mineral present in the bone. Moreover, the in vitro anticancer activity was preserved when tested in commercial and patient-treated derived pediatric osteosarcoma cells. Further in vivo studies will shed light on the potential of these nanomedicines for the treatment of bone sarcomas.

Supramolecular organization and biological interaction of squalenoyl siRNA nanoparticles.

Small interfering RNAs (siRNA) are attractive and powerful tools to inhibit the expression of a targeted gene. However, their extreme hydrophilicities combined with a negative charge and short plasma half-life counteract their use as therapeutics. Previously, we chemically linked siRNA to squalene (SQ) which self-assembled as nanoparticles (NPs) with pharmacological efficiency in cancers and recently in a hereditary neuropathy. In order to understand the siRNA-SQ NP assembly and fate once intravenously injected, the present study detailed characterization of siRNA-SQ NP structure and its interaction with serum components. From SAXS and SANS analysis, we propose that the siRNA-SQ bioconjugate self-assembled as 11-nm diameter supramolecular assemblies, which are connected one to another to form spherical nanoparticles of around 130-nm diameter. The siRNA-SQ NPs were stable in biological media and interacted with serum components, notably with albumin and LDL. The high specificity of siRNA to decrease or normalize gene expression and the high colloidal stability when encapsulated into squalene nanoparticles offer promising targeted therapy with wide applications for pathologies with gene expression dysregulation.

Gemcitabine lipid prodrug nanoparticles: Switching the lipid moiety and changing the fate in the bloodstream.

A simple approach to achieve a lipoprotein (LP)-mediated drug delivery is to trigger the spontaneous drug insertion into endogenous lipoproteins in the bloodstream, by means of its chemical modification. Nanoparticles (NPs) made of the squalene-gemcitabine (SQGem) conjugate were found to have a high affinity for plasma lipoproteins while free gemcitabine did not, suggesting a key role of the lipid moiety in this event. Whether the drug conjugation to cholesterol, one of the major lipoprotein-transported lipids, could also promote an analogous interaction was a matter of question. NPs made of the cholesterol-gemcitabine conjugate (CholGem) have been herein thoroughly investigated for their blood distribution profile both in vitro and in vivo. Unexpectedly, contrarily to SQGem, no trace of the CholGem prodrug could be found in the lipoprotein fractions, nor was it interacting with albumin. The investigation of isolated NPs and NPs/LPs physical mixtures provided a further insight into the lack of interaction of CholGem NPs with LPs. Although essential for allowing the self-assembly of the prodrug into nanoparticles, the lipid moiety may not be sufficient to elicit interaction of the conjugated drug with plasma lipoproteins but the whole NP physicochemical features must be carefully considered.

Investigation of squalene-doxorubicin distribution and interactions within single cancer cell using Raman microspectroscopy.

Intracellular distribution of doxorubicin (DOX) and its squalenoylated (SQ-DOX) nanoparticles (NPs) form in murine lung carcinoma M109 and human breast carcinoma MDA-MB-231 cells was investigated by Raman microspectroscopy. Pharmacological data showed that DOX induced higher cytotoxic effect than SQ-DOX NPs. Raman data were obtained using single-point measurements and imaging on the whole cell areas. These data showed that after DOX treatment at 1 µM, the spectral features of DOX were not detected in the M109 cell cytoplasm and nucleus. However, the intracellular distribution of SQ-DOX NPs was higher than DOX in the same conditions. In addition, SQ-DOX NPs were localized into both cell cytoplasm and nucleus. After 5 µM treatment, Raman bands of DOX at 1211 and 1241 cm-1 were detected in the nucleus. Moreover, the intensity ratio of these bands decreased, indicating DOX intercalation into DNA. However, after treatment with SQ-DOX NPs, the intensity of these Raman bands increased. Interestingly, with SQ-DOX NPs, the intensity of 1210/1241 cm-1 ratio was higher suggesting a lower fraction of intercalated DOX in DNA and higher amount of non-hydrolyzed SQ-DOX. Raman imaging data confirm this subcellular localization of these drugs in both M109 and MDA-MB-231 cells. These finding brings new insights to the cellular characterization of anticancer drugs at the molecular level, particularly in the field of nanomedicine.

Gemcitabine Lipid Prodrugs: The Key Role of the Lipid Moiety on the Self-Assembly into Nanoparticles.

A small library of amphiphilic prodrugs has been synthesized by conjugation of gemcitabine (Gem) (a hydrophilic nucleoside analogue) to a series of lipid moieties and investigated for their capacity to spontaneously self-assemble into nanosized objects by simple nanoprecipitation. Four of these conjugates formed stable nanoparticles (NPs), while with the others, immediate aggregation occurred, whatever the tested experimental conditions. Whether such capacity could have been predicted based on the prodrug physicochemical features was a matter of question. Among various parameters, the hydrophilic-lipophilic balance (HLB) value seemed to hold a predictive character. Indeed, we identified a threshold value which well correlated with the tendency (or not) of the synthesized prodrugs to form stable nanoparticles. Such a hypothesis was further confirmed by broadening the analysis to Gem and other nucleoside prodrugs already described in the literature. We also observed that, in the case of Gem prodrugs, the lipid moiety affected not only the colloidal properties but also the in vitro anticancer efficacy of the resulting nanoparticles. Overall, this study provides a useful demonstration of the predictive potential of the HLB value for lipid prodrug NP formulation and highlights the need of their opportune in vitro screening, as optimal drug loading does not always translate in an efficient biological activity.

Squalenoyl siRNA PMP22 nanoparticles are effective in treating mouse models of Charcot-Marie-Tooth disease type 1 A.

Charcot-Marie-Tooth disease type 1 A (CMT1A) lacks an effective treatment. We provide a therapy for CMT1A, based on siRNA conjugated to squalene nanoparticles (siRNA PMP22-SQ NPs). Their administration resulted in normalization of Pmp22 protein levels, restored locomotor activity and electrophysiological parameters in two transgenic CMT1A mouse models with different severity of the disease. Pathological studies demonstrated the regeneration of myelinated axons and myelin compaction, one major step in restoring function of myelin sheaths. The normalization of sciatic nerve Krox20, Sox10 and neurofilament levels reflected the regeneration of both myelin and axons. Importantly, the positive effects of siRNA PMP22-SQ NPs lasted for three weeks, and their renewed administration resulted in full functional recovery. Beyond CMT1A, our findings can be considered as a potent therapeutic strategy for inherited peripheral neuropathies. They provide the proof of concept for a new precision medicine based on the normalization of disease gene expression by siRNA.

New Nanoparticle Formulation for Cyclosporin A: In Vitro Assessment.

Cyclosporin A (CsA) is a molecule with well-known immunosuppressive properties. As it also acts on the opening of mitochondrial permeability transition pore (mPTP), CsA has been evaluated for ischemic heart diseases (IHD). However, its distribution throughout the body and its physicochemical characteristics strongly limit the use of CsA for intravenous administration. In this context, nanoparticles (NPs) have emerged as an opportunity to circumvent the above-mentioned limitations. We have developed in our laboratory an innovative nanoformulation based on the covalent bond between squalene (Sq) and cyclosporin A to avoid burst release phenomena and increase drug loading. After a thorough characterization of the bioconjugate, we proceeded with a nanoprecipitation in aqueous medium in order to obtain SqCsA NPs of well-defined size. The SqCsA NPs were further characterized using dynamic light scattering (DLS), cryogenic transmission electron microscopy (cryoTEM), and high-performance liquid chromatography (HPLC), and their cytotoxicity was evaluated. As the goal is to employ them for IHD, we evaluated the cardioprotective capacity on two cardiac cell lines. A strong cardioprotective effect was observed on cardiomyoblasts subjected to experimental hypoxia/reoxygenation. Further research is needed in order to understand the mechanisms of action of SqCsA NPs in cells. This new formulation of CsA could pave the way for possible medical application.

Synthesis and Biopharmaceutical Characterization of Amphiphilic Squalenyl Derivative Based Versatile Drug Delivery Platform.

Limited drug loading capacity (LC), mostly below 5% w/w, is a significant drawback of nanoparticulate drug delivery systems (DDS). Squalenoylation technology, which employs bioconjugation of squalenyl moiety and drug, allows self-assemble of nanoparticles (NPs) in aqueous media with significantly high LC (>30% w/w). The synthesis and particle preparation of squalenoylated prodrugs are, however, not facile for molecules with multiple reactive groups. Taking a different approach, we describe the synthesis of amphiphilic squalenyl derivatives (SqDs) as well as the physicochemical and biopharmaceutical characterizations of their self-assembled NPs as DDSs. The SqDs included in this study are (i) cationic squalenyl diethanolamine (ii) PEGylated SqD (PEG 750 Da), (iii) PEGylated SqD (PEG 3,000 Da), and (iv) anionic squalenyl hydrogen sulfate. All four SqDs self-assemble into NPs in a size range from 100 to 200 nm in an aqueous solution. Furthermore, all NP derivatives demonstrate appropriate biocompatibility and adequate colloidal stability in physiological relevant pH environments. The mucoprotein binding of PEGylated NPs is reduced compared to the charged NPs. Most importantly, this technology allows excellent LC (at maximum of 45% w/w) of a wide range of multifunctional compounds, varying in physicochemical properties and molecular weight. Interestingly, the drug release profile can be tuned by different loading methods. In summary, the SqD-based NPs appear as versatile drug delivery platforms.

Combinatorial Nanomedicine Made of Squalenoyl-Gemcitabine and Edelfosine for the Treatment of Osteosarcoma.

Due to chemoresistance and a high propensity to form lung metastasis, survival rates in pediatric osteosarcoma (OS) are poor. With the aim to improve anticancer activity in pediatric OS, a multidrug nanomedicine was designed using the alkyl-lysophospholipid edelfosine (EF) co-assembled with squalenoyl-gemcitabine (SQ-Gem) to form nanoassemblies (NAs) of 50 nm. SQ-Gem/EF NAs modified the total Gem pool exposure in the blood stream in comparison with SQ-Gem NAs, which correlated with a better tolerability and a lower toxicity profile after multiple intravenous administrations in mice. For in vivo preclinical assessment in an orthotopic OS tumor model, P1.15 OS cells were intratibially injected in athymic nude mice. SQ-Gem/EF NAs considerably decreased the primary tumor growth kinetics and reduced the number of lung metastases. Our findings support the candidature of this anticancer nanomedicine as a potential pediatric OS therapy.

Inhibition of in vitro Ebola infection by anti-parasitic quinoline derivatives.

There continues to be no approved drugs for the treatment of Ebola virus disease (EVD). Despite a number of candidate drugs showing limited efficacy in vitro and/or in non-human primate studies, EVD continues to plaque certain areas of Africa without any efficacious treatments yet available. Recently, we have been exploring the potential for anti-malarial drugs to inhibit an in vitro model of Ebola Zaire replication using a transcription-competent virus-like particle (trVLP) assay. We examined the efficacy of chloroquine, amodiaquine and 36 novel anti-parasite quinoline derivatives at inhibiting Ebola virus replication. Drug efficacy was tested by trVLP assay and toxicity by MTT assay. Both chloroquine and amodiaquine were effective for inhibition of Ebola virus replication without significant toxicity. The half-maximal inhibitory concentration (IC 50) of chloroquine and amodiaquine to inhibit Ebola virus replication were IC 50, Chl = 3.95 µM and IC 50, Amo = 1.45 µM, respectively. Additionally, three novel quinoline derivatives were identified as having inhibitory activity and low toxicity for Ebola trVLP replication, with 2NH2Q being the most promising derivative, with an IC 50 of 4.66 µM. Quinoline compounds offer many advantages for disease treatment in tropical climates as they are cheap to produce, easy to synthesize and chemically stable. In this report, we have demonstrated the potential of anti-parasite quinolines for further investigation for use in EVD.

A New Model Applied for Evaluating a Rhenium-diselenium Drug: Breast Cancer Cells Stimulated by Cytokines Induced from Polynuclear Cells by LPS.

BACKGROUND/AIM: New anticancer drugs are usually tested on cancer cells in culture in a standard medium. We stimulated immune polynuclear cells by lipopolysaccharides to obtain an enriched medium (EM) containing inflammatory cytokines more closely reflecting the tumor microenvironment and tested a rhenium-diselenium (Re-diSe) drug in this new model. Concentrations of cytokines were compared with a control medium (CM). MATERIALS AND METHODS: Human-derived breast cancer cells were grown in culture either in CM or EM with or without Re-diSe. Assays of tumor necrosis factor alpha (TNFα), interleukin 6 (IL6), intereukin 1 beta (IL1ß), transforming growth factor-beta (TGFß), insulin growth factor 1 (IGF1) and vascular epidermal growth factor A (VEGFA) were performed by enzyme-linked immunosorbent assays. The production of reactive oxygen species (ROS) was determined by 2,7-dichlorofluorescein test. The cell growth was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tests. RESULTS: Concentrations of TNFα, IL6 and Il1ß were observed to be significantly higher in EM than in CM. There was no difference for TGFß, IGF1 and VEGFA. The cells were sensitive to Re-diSe, with reduced concentrations of TGFß, IGF1, VEGFA and ROS, but the half-maximal inhibitory concentration was significantly higher in EM than in CM. CONCLUSION: The efficacy of the Re-diSe drug was confirmed in this model of aggressive cancer.

Squalenyl Hydrogen Sulfate Nanoparticles for Simultaneous Delivery of Tobramycin and an Alkylquinolone Quorum Sensing Inhibitor Enable the Eradication of P.†aeruginosa Biofilm Infections.

Elimination of pulmonary Pseudomonas aeruginosa (PA) infections is challenging to accomplish with antibiotic therapies, mainly due to resistance mechanisms. Quorum sensing inhibitors (QSIs) interfering with biofilm formation can thus complement antibiotics. For simultaneous and improved delivery of both active agents to the infection sites, self-assembling nanoparticles of a newly synthesized squalenyl hydrogen sulfate (SqNPs) were prepared. These nanocarriers allowed for remarkably high loading capacities of hydrophilic antibiotic tobramycin (Tob) and a novel lipophilic QSI at 30 % and circa 10 %, respectively. The drug-loaded SqNPs showed improved biofilm penetration and enhanced efficacy in relevant biological barriers (mucin/human tracheal mucus, biofilm), leading to complete eradication of PA biofilms at circa 16-fold lower Tob concentration than Tob alone. This study offers a viable therapy optimization and invigorates the research and development of QSIs for clinical use.