Fluorescence lifetime nanothermometer based on the equilibrium formation of anthracene AIE-excimers in living cells.

The effective measurement of temperature in living systems at the nano and microscopic scales continues to be a challenge to this day. Here, we study the use of 2-(anthracen-2-yl)-1,3-diisopropylguanidine, 1, as a nanothermometer based on fluorescence lifetime measurements and its bioimaging applications. In aqueous solution, 1 is shown in aggregated form and the equilibrium between the two main aggregate types (T-shaped and π-π) is highly sensitive to the temperature. The heating of the medium shifts the equilibrium toward the formation of highly emissive T-shaped aggregates. This species shows a high fluorescence emission and a long lifetime in comparison with the π-π aggregates and the freé monomer. A linear relationship between the fluorescence lifetime and the temperature both in aqueous solution and in a synthetic intracellular buffer was found. Fluorescence lifetime imaging microscopy (FLIM) also showed a linear relationship between lifetime and temperature with an excellent sensitivity in MCF7 breast cancer cells, which opens the door for its potential use as FLIM nanothermometer in the biomedical field.

Evaluation of heteroscorpionate ligands as scaffolds for the generation of Ruthenium(II) metallodrugs in breast cancer therapy.

The modular synthesis of the heteroscorpionate core is explored as a tool for the rapid development of ruthenium-based therapeutic agents. Starting with a series of structurally diverse alcohol-NN ligands, a family of heteroscorpionate-based ruthenium derivatives was synthesized, characterized, and evaluated as an alternative to platinum therapy for breast cancer therapy. In vitro, the antitumoral activity of the novel derivatives was assessed in a series of breast cancer cell lines using UNICAM-1 and cisplatin as metallodrug control. Through this approach, a bimetallic heteroscorpionate-based metallodrug (RUSCO-2) was identified as the lead compound of the series with an IC50 value range as low as 3-5 µM. Notably, RUSCO-2 was found to be highly cytotoxic in TNBC cell lines, suggesting a mode of action independent of the receptor status of the cells. As a proof of concept and taking advantage of the luminescent properties of one of the complexes obtained, uptake was monitored in human breast cancer MCF7 cell lines by fluorescence lifetime imaging microscopy (FLIM) to reveal that the compound is evenly distributed in the cytoplasm and that the incorporation of the heteroscorpionate ligand protects it from aqueous processes, conversion in another entity, or the loss of the chloride group. Finally, ROS studies were conducted, lipophilicity was estimated, the chloride/water exchange was studied, and stability studies in simulated biological media were carried out to propose structure-activity relationships.

Formation of Highly Emissive Anthracene Excimers for Aggregation-Induced Emission/Self-Assembly Directed (Bio)imaging.

AIEgens have emerged as a promising alternative to molecular rotors in bioimaging applications. However, transferring the concept of aggregation-induced emission (AIE) from solution to living systems remains a challenge. Given the highly heterogeneous nature and the compartmentalization of the cell, different approaches are needed to control the self-assembly within the crowded intricate cellular environment. Herein, we report for the first time the self-assembly mechanism of an anthracene-guanidine derivative (AG) forming the rare and highly emissive T-shaped dimer in breast cancer cell lines as a proof of concept. This process is highly sensitive to the local environment in terms of polarity, viscosity, and/or water quantity that should enable the use of the AG as a fluorescence lifetime imaging biosensor for intracellular imaging of cellular structures and the monitoring of intracellular state parameters. Different populations of the monomer and T-shaped and π-π dimers were observed in the cell membrane, cytoplasm, and nucleoplasm, related to the local viscosity and presence of water. The T-shaped dimer is formed preferentially in the nucleus because of the higher density and viscosity compared to the cytoplasm. The present results should serve as a precursor for the development of new design strategies for molecular systems for a wide range of applications such as cell viscosity, density, or temperature sensing and imaging.

Guanylation Reactions for the Rational Design of Cancer Therapeutic Agents.

The modular synthesis of the guanidine core by guanylation reactions using commercially available ZnEt2 as a catalyst has been exploited as a tool for the rapid development of antitumoral guanidine candidates. Therefore, a series of phenyl-guanidines were straightforwardly obtained in very high yields. From the in vitro assessment of the antitumoral activity of such structurally diverse guanidines, the guanidine termed ACB3 has been identified as the lead compound of the series. Several biological assays, an estimation of AMDE values, and an uptake study using Fluorescence Lifetime Imaging Microscopy were conducted to gain insight into the mechanism of action. Cell death apoptosis, induction of cell cycle arrest, and reduction in cell adhesion and colony formation have been demonstrated for the lead compound in the series. In this work, and as a proof of concept, we discuss the potential of the catalytic guanylation reactions for high-throughput testing and the rational design of guanidine-based cancer therapeutic agents.

Minimizing sperm oxidative stress using nanotechnology for breeding programs in rams.

BACKGROUND: Artificial insemination (AI) is a routine breeding technology in animal reproduction. Nevertheless, the temperature-sensitive nature and short fertile lifespan of ram sperm samples hamper its use in AI. In this sense, nanotechnology is an interesting tool to improve sperm protection due to the development of nanomaterials for AI, which could be used as delivery vehicles. In this work, we explored the feasibility of vitamin E nanoemulsion (NE) for improving sperm quality during transport. RESULTS: With the aim of evaluating this proposal, ejaculates of 7 mature rams of Manchega breed were collected by artificial vagina and extended to 60 × 106 spz/mL in Andromed®. Samples containing control and NE (12 mmol/L) with and without exogenous oxidative stress (100 µmol/L Fe2+/ascorbate) were stored at 22 and 15 ºC and motility (CASA), viability (YO-PRO/PI), acrosomal integrity (PNA-FITC/PI), mitochondrial membrane potential (Mitotracker Deep Red 633), lipoperoxidation (C11 BODIPY 581/591), intracellular reactive oxygen species (ROS) production and DNA status (SCSA®) monitored during 96 h. Our results show that NE could be used to maintain ram spermatozoa during transport at 15 and 22 ºC for up to 96 h, with no appreciable loss of kinematic and physiological characteristics of freshly collected samples. CONCLUSIONS: The storage of ram spermatozoa in liquid form for 2-5 d with vitamin E nanoemulsions may lead more flexibility to breeders in AI programs. In view of the potential and high versatility of these nanodevices, further studies are being carried out to assess the proposed sperm preservation medium on fertility after artificial insemination.

Macrophage Cell Membrane Coating on Piperine-Loaded MIL-100(Fe) Nanoparticles for Breast Cancer Treatment.

Piperine (PIP), a compound found in Piper longum, has shown promise as a potential chemotherapeutic agent for breast cancer. However, its inherent toxicity has limited its application. To overcome this challenge, researchers have developed PIP@MIL-100(Fe), an organic metal-organic framework (MOF) that encapsulates PIP for breast cancer treatment. Nanotechnology offers further treatment options, including the modification of nanostructures with macrophage membranes (MM) to enhance the evasion of the immune system. In this study, the researchers aimed to evaluate the potential of MM-coated MOFs encapsulated with PIP for breast cancer treatment. They successfully synthesized MM@PIP@MIL-100(Fe) through impregnation synthesis. The presence of MM coating on the MOF surface was confirmed through SDS-PAGE analysis, which revealed distinct protein bands. Transmission electron microscopy (TEM) images demonstrated the existence of a PIP@MIL-100(Fe) core with a diameter of around 50 nm, surrounded by an outer lipid bilayer layer measuring approximately 10 nm in thickness. Furthermore, the researchers evaluated the cytotoxicity indices of the nanoparticles against various breast cancer cell lines, including MCF-7, BT-549, SKBR-3, and MDA. The results demonstrated that the MOFs exhibited between 4 and 17 times higher cytotoxicity (IC50) in all four cell lines compared to free PIP (IC50 = 193.67 ± 0.30 µM). These findings suggest that MM@PIP@MIL-100(Fe) holds potential as an effective treatment for breast cancer. The study's outcomes highlight the potential of utilizing MM-coated MOFs encapsulated with PIP as an innovative approach for breast cancer therapy, offering improved cytotoxicity compared to free PIP alone. Further research and development are warranted to explore the clinical translation and optimize the efficacy and safety of this treatment strategy.

Synthesis, characterization, and antibacterial activities of a heteroscorpionate derivative platinum complex against methicillin-resistant Staphylococcus aureus.

Staphylococcus aureus is one of the species with the greatest clinical importance and greatest impact on public health. In fact, methicillin-resistant S. aureus (MRSA) is considered a pandemic pathogen, being essential to develop effective medicines and combat its rapid spread. This study aimed to foster the translation of clinical research outcomes based on metallodrugs into clinical practice for the treatment of MRSA. Bearing in mind the promising anti-Gram-positive effect of the heteroscorpionate ligand 1,1'-(2-(4-isopropylphenyl)ethane-1,1-diyl)bis(3,5-dimethyl-1H-pyrazole) (2P), we propose the coordination of this compound to platinum as a clinical strategy with the ultimate aim of overcoming resistance in the treatment of MRSA. Therefore, the novel metallodrug 2P-Pt were synthetized, fully characterized and its antibacterial effect against the planktonic and biofilm state of S. aureus evaluated. In this sense, three different strains of S. aureus were studied, one collection strain of S. aureus sensitive to methicillin and two clinical MRSA strains. To appraise the antibacterial activity, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC), and minimum biofilm eradication concentration (MBEC) were determined. Moreover, successful outcomes on the development of biofilm in a wound-like medium were obtained. The mechanism of action for 2P-Pt was proposed by measuring the MIC and MBC with EDTA (cation mediated mechanism) and DMSO (exogenous oxidative stress mechanism). Moreover, to shed light on the plausible antistaphylococcal mechanism of this novel platinum agent, additional experiments using transmission electron microscopy were carried out. 2P-Pt inhibited the growth and eradicated the three strains evaluated in the planktonic state. Another point worth stressing is the inhibition in the growth of MRSA biofilm even in a wounded medium. The results of this work support this novel agent as a promising therapeutic alternative for preventing infections caused by MRSA.

Unexpected luminescence of non-conjugated biomass-based polymers: new approach in photothermal imaging.

Population growth, depletion of world resources and persistent toxic chemical production underline the need to seek new smart materials from inexpensive, biodegradable, and renewable feedstocks. Hence, "metal-free" ring-opening copolymerization to convert biomass carvone-based monomers into non-conventional luminescent biopolymers is considered a sustainable approach to achieve these goals. The non-conventional emission was studied in terms of steady-state and time-resolved spectroscopy in order to unravel the structure-properties for different carvone-based copolymers. The results highlighted the importance of the final copolymer folding structure as well as its environment in luminescent behavior (cluster-triggered emission). In all cases, their luminescent behavior is sensitive to small temperature fluctuations (where the minimum detected temperature is Tm ∼ 2 °C and relative sensitivity is Sr ∼ 6% °C) even at the microscopic scale, which endows these materials a great potential as thermosensitive smart polymers for photothermal imaging.

Vitamin E Lipid-Based Nanodevices as a Tool for Ovine Sperm Protection against Oxidative Stress: Impact on Sperm Motility.

The advent of nanotechnology in the field of animal reproduction has led to the development of safer and more efficient therapies. The use of nanotechnology allows us to avoid the detrimental effects of certain traditional antioxidants, such as Vitamin E. Its hydrophobic nature makes mandatory the use of organic solvents, which are toxic to sperm cells. This study aims to evaluate the efficiency of vitamin E nanoemulsions (NE) on ram (Ovis aries) spermatozoa. For this purpose, the effect of three NE concentrations (6, 12, and 24 mM) were assessed on sperm of 10 mature rams of the Manchega breed. Sperm samples were collected by artificial vagina, pooled, and diluted in Bovine Gamete Medium. The samples were stored at 37 °C and assessed at 0, 4, 8, and 24 h under oxidative stress conditions (100 µM Fe2+/ascorbate). Motility (CASA), viability (YO-PRO/IP), acrosomal integrity (PNA-FITC/IP), mitochondrial membrane potential (Mitotracker Deep Red 633), lipoperoxidation (C11 BODIPY 581/591), intracellular reactive oxygen species (ROS) production and DNA status (SCSA®®) were assessed. A linear mixed-effects models were used to analyze the effects of time, NE, and oxidant (fixed factors) on sperm parameters, and a random effect on the male was also included in the model with Tukey's post hoc test. Protection of ram spermatozoa with NE resulted in a more vigorous motility under oxidative stress conditions with respect Control and Free vitamin E, while preventing the deleterious effects of oxidative stress coming from the production of free radicals and lipid peroxidation. These results ascertain the high relevance of the use of delivery systems for sperm physiology preservation in the context of assisted reproduction techniques.

Enhanced Antitumoral Activity of Encapsulated BET Inhibitors When Combined with PARP Inhibitors for the Treatment of Triple-Negative Breast and Ovarian Cancers.

BRCA1/2 protein-deficient or mutated cancers comprise a group of aggressive malignancies. Although PARPis have shown considerably efficacy in their treatment, the widespread use of these agents in clinical practice is restricted by various factors, including the development of acquired resistance due to the presence of compensatory pathways. BETis can completely disrupt the HR pathway by repressing the expression of BRCA1 and could be aimed at generation combination regimes to overcome PARPi resistance and enhance PARPi efficacy. Due to the poor pharmacokinetic profile and short half-life, the first-in-class BETi JQ1 was loaded into newly developed nanocarrier formulations to improve the effectivity of olaparib for the treatment of BRCAness cancers. First, polylactide polymeric nanoparticles were generated by double emulsion. Moreover, liposomes were prepared by ethanol injection and evaporation solvent method. JQ1-loaded drug delivery systems display optimal hydrodynamic radii between 60 and 120 nm, with a very low polydispersity index (PdI), and encapsulation efficiencies of 92 and 16% for lipid- and polymeric-based formulations, respectively. Formulations show high stability and sustained release. We confirmed that all assayed JQ1 formulations improved antiproliferative activity compared to the free JQ1 in models of ovarian and breast cancers. In addition, synergistic interaction between JQ1 and JQ1-loaded nanocarriers and olaparib evidenced the ability of encapsulated JQ1 to enhance antitumoral activity of PARPis.

Polylactide Perspectives in Biomedicine: From Novel Synthesis to the Application Performance.

The incessant developments in the pharmaceutical and biomedical fields, particularly, customised solutions for specific diseases with targeted therapeutic treatments, require the design of multicomponent materials with multifunctional capabilities. Biodegradable polymers offer a variety of tailored physicochemical properties minimising health adverse side effects at a low price and weight, which are ideal to design matrices for hybrid materials. PLAs emerge as an ideal candidate to develop novel materials as are endowed withcombined ambivalent performance parameters. The state-of-the-art of use of PLA-based materials aimed at pharmaceutical and biomedical applications is reviewed, with an emphasis on the correlation between the synthesis and the processing conditions that define the nanostructure generated, with the final performance studies typically conducted with either therapeutic agents by in vitro and/or in vivo experiments or biomedical devices.

Multifunctional PLA/Gelatin Bionanocomposites for Tailored Drug Delivery Systems.

A series of bionanocomposites composed of shark gelatin hydrogels and PLA nanoparticles featuring different nanostructures were designed to generate multifunctional drug delivery systems with tailored release rates required for personalized treatment approaches. The global conception of the systems was considered from the desired customization of the drug release while featuring the viscoelastic properties needed for their ease of storage and posterior local administration as well as their biocompatibility and cell growth capability for the successful administration at the biomolecular level. The hydrogel matrix offers the support to develop a direct thermal method to convert the typical kinetic trapped nanostructures afforded by the formulation method whilst avoiding the detrimental nanoparticle agglomeration that diminishes their therapeutic effect. The nanoparticles generated were successfully formulated with two different antitumoral compounds (doxorubicin and dasatinib) possessing different structures to prove the loading versatility of the drug delivery system. The bionanocomposites were characterized by several techniques (SEM, DLS, RAMAN, DSC, SAXS/WAXS and rheology) as well as their reversible sol-gel transition upon thermal treatment that occurs during the drug delivery system preparation and the thermal annealing step. In addition, the local applicability of the drug delivery system was assessed by the so-called "syringe test" to validate both the storage capability and its flow properties at simulated physiological conditions. Finally, the drug release profiles of the doxorubicin from both the PLA nanoparticles or the bionanocomposites were analyzed and correlated to the nanostructure of the drug delivery system.

Clinical considerations for the design of PROTACs in cancer.

Degradation of targeted proteins using proteolysis targeting chimeras (PROTACs) has gained momentum. A PROTAC is a bifunctional molecule that consists of three parts: a ligand that interacts with the protein to be degraded, another ligand that binds to an E3 ubiquitin ligase and a linker that connects both. Identification of the right proteins as targets to be degraded and a ligase that is highly expressed in tumors compare with normal tissue is mandatory, as can augment efficacy reducing toxicity. In this article we review the current development stage of PROTACs in cancer to categorize the best PROTAC construction. Targets including BCL2, CDK4 and MCL1 were highly expressed in all tumors; MCL1 was significantly increased in breast cancer and lung adenocarcinoma and CDK4 in colon adenocarcinoma. Degradation of CDK9, AURKA or PLK1, followed by BCL2, MCL1, PTPN11, BRD4, PTK2, showed a high dependency. Most ligases evaluated were not highly present in tumors except for MDM2 in breast, lung, prostate and gastric cancer. In non-transformed tissue MDM2 was the most abundant ligase, followed by cIAP and CRBN, and those with low expression included XIAP and VHL. MDM2 ligase coupled with inhibitors of the targets BCL2, BRD4, CDK9, PLK1 and MCL1 in stomach tumor, and MDM2 with PIK3C3 inhibitors in breast cancer, seems to be the best therapeutic strategy. Our results suggest potential options for the design of PROTACS in specific medical indications.

A bis(pyrazolyl)methane derivative against clinical Staphylococcus aureus strains isolated from otitis externa.

OBJECTIVE: The purpose of this study was to evaluate the in vitro antibacterial effects of a p-Cymene-based bis(pyrazolyl)methane derivative (SC-19) to advance in developing alternative therapeutic compounds to fight against bacterial isolates from patients with otitis externa (OE). METHODS: Eighteen swab specimens were collected from patients aged over 18 years diagnosed with OE within at least 7 days of symptom onset, contaminated by only one bacterium type: Pseudomonas aeruginosa (n = 5); Staphylococcus aureus (n = 8); Klebsiella aerogenes (n = 2); Serratia marcescens (n = 1); Morganella morganii (n = 2). To appraise antibacterial activity, minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC), and minimum biofilm eradication concentration (MBEC) assays were run at different SC-19 concentrations. RESULTS: When using SC-19, S. aureus strains showed less bacterial growth, but no bactericidal effect was observed. The MIC and MBC of SC-19 were 62.5 and 2000 µg/ml against S. aureus and were >2000 µg/ml against the other isolates obtained from OE, respectively. In addition, the MBICs and MBECs of SC-19 against S. aureus were 125 and >2000 µg/ml, respectively. CONCLUSION: Nowadays the acquired antibiotic resistance phenomenon has stimulated research into novel and more efficient therapeutic agents. Hence, we report that, helped by the structural diversity fostered herein by a range of bis(pyrazolyl)methane derivatives, SC-19 can be a promising alternative therapeutic option for treating OE caused by S. aureus given the observed effects on both planktonic state and biofilm. LEVEL OF EVIDENCE: IV.

Synthesis of High Molecular Weight Stereo-Di-Block Copolymers Driven by a Co-Initiator Free Catalyst.

Stereo-diblock copolymers of high molecular weight polylactide (PLA) were synthetized by the one pot-sequential addition method assisted by a heteroscorpionate catalyst without the need of a co-initiator. The alkyl zinc organometallic heteroscorpionate derivative (Zn(Et)(κ3-bpzteH)] (bpzteH = 2,2-bis(3,5-dimethylpyrazol-1-yl)-1-para-tolylethoxide) proved to assist in the mechanism of reaction following a coordination-insertion process. Kinetic studies along with the linear correlation between monomer and number average molecular weight (Mn) conversion, and the narrow polydispersities supported the truly living polymerization character of the initiator, whereas matrix-assisted laser desorption/Ionization-time of flight (MALDI-TOF) studies showed a very low order of transesterification. The high stereo-control attained for the afforded high molecular weight derivatives was revealed by homonuclear decoupled 1H NMR spectra and polarimetry measurements. The nanostructure of the PLA derivatives was studied by both wide-angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC) and the stereocomplex phase of the PLA stereo-diblock copolymers was successfully identified.

Vitamin E Delivery Systems Increase Resistance to Oxidative Stress in Red Deer Sperm Cells: Hydrogel and Nanoemulsion Carriers.

Oxidative stress has become a major concern in the field of spermatology, and one of the possible solutions to this acute problem would be the use of antioxidant protection; however, more studies are required in this field, as highly contradictory results regarding the addition of antioxidants have been obtained. Vitamin E is a powerful biological antioxidant, but its low stability and high hydrophobicity limit its application in spermatology, making the use of organic solvents necessary, which renders spermatozoa practically motionless. Keeping this in mind, we propose the use of hydrogels (HVEs) and nanoemulsions (NVEs), alone or in combination, as carriers for the controlled release of vitamin E, thus, improving its solubility and stability and preventing oxidative stress in sperm cells. Cryopreserved sperm from six stags was thawed and extended to 30 × 106 sperm/mL in Bovine Gamete Medium (BGM). Once aliquoted, the samples were incubated as follows: control, free vitamin E (1 mM), NVEs (9 mM), HVEs (1 mM), and the combination of HVEs and NVEs (H + N), with or without induced oxidative stress (100 µM Fe2+/ascorbate). The different treatments were analyzed after 0, 2, 5, and 24 h of incubation at 37 °C. Motility (CASA®), viability (YO-PRO-1/IP), mitochondrial membrane potential (Mitotracker Deep Red 633), lipid peroxidation (C11 BODIPY 581/591), intracellular reactive oxygen species production (CM-H2DCFDA), and DNA status (SCSA®) were assessed. Our results show that the deleterious effects of exogenous oxidative stress were prevented by the vitamin E-loaded carriers proposed, while the kinematic sperm parameters (p ˂ 0.05) and sperm viability were always preserved. Moreover, the vitamin E formulations maintained and preserved mitochondrial activity, prevented sperm lipid peroxidation, and decreased reactive oxygen species (ROS) production (p ˂ 0.05) under oxidative stress conditions. Vitamin E formulations were significantly different as regards the free vitamin E samples (p < 0.001), whose sperm kinematic parameters drastically decreased. This is the first time that vitamin E has been formulated as hydrogels. This new formulation could be highly relevant for sperm physiology preservation, signifying an excellent approach against sperm oxidative damage.

Tuning the Cytotoxicity of Bis-Phosphino-Amines Ruthenium(II) Para-Cymene Complexes for Clinical Development in Breast Cancer.

Despite some limitations such as long-term side effects or the potential presence of intrinsic or acquired resistance, platinum compounds are key therapeutic components for the treatment of several solid tumors. To overcome these limitations, maintaining the same efficacy, organometallic ruthenium(II) compounds have been proposed as a viable alternative to platinum agents as they have a more favorable toxicity profile and represent an ideal template for both, high-throughput and rational drug design. To support the preclinical development of bis-phoshino-amine ruthenium compounds in the treatment of breast cancer, we carried out chemical modifications in the structure of these derivatives with the aim of designing less toxic and more efficient therapeutic agents. We report new bis-phoshino-amine ligands and the synthesis of their ruthenium counterparts. The novel ligands and compounds were fully characterized, water stability analyzed, and their in vitro cytotoxicity against a panel of tumor cell lines representative of different breast cancer subtypes was evaluated. The mechanism of action of the lead compound of the series was explored. In vivo toxicity was also assessed. The results obtained in this article might pave the way for the clinical development of these compounds in breast cancer therapy.

Mithramycin delivery systems to develop effective therapies in sarcomas.

BACKGROUND: Sarcomas comprise a group of aggressive malignancies with very little treatment options beyond standard chemotherapy. Reposition of approved drugs represents an attractive approach to identify effective therapeutic compounds. One example is mithramycin (MTM), a natural antibiotic which has demonstrated a strong antitumour activity in several tumour types, including sarcomas. However, its widespread use in the clinic was limited by its poor toxicity profile. RESULTS: In order to improve the therapeutic index of MTM, we have loaded MTM into newly developed nanocarrier formulations. First, polylactide (PLA) polymeric nanoparticles (NPs) were generated by nanoprecipitation. Also, liposomes (LIP) were prepared by ethanol injection and evaporation solvent method. Finally, MTM-loaded hydrogels (HG) were obtained by passive loading using a urea derivative non-peptidic hydrogelator. MTM-loaded NPs and LIP display optimal hydrodynamic radii between 80 and 105 nm with a very low polydispersity index (PdI) and encapsulation efficiencies (EE) of 92 and 30%, respectively. All formulations show a high stability and different release rates ranging from a fast release in HG (100% after 30 min) to more sustained release from NPs (100% after 24 h) and LIP (40% after 48 h). In vitro assays confirmed that all assayed MTM formulations retain the cytotoxic, anti-invasive and anti-stemness potential of free MTM in models of myxoid liposarcoma, undifferentiated pleomorphic sarcoma and chondrosarcoma. In addition, whole genome transcriptomic analysis evidenced the ability of MTM, both free and encapsulated, to act as a multi-repressor of several tumour-promoting pathways at once. Importantly, the treatment of mice bearing sarcoma xenografts showed that encapsulated MTM exhibited enhanced therapeutic effects and was better tolerated than free MTM. CONCLUSIONS: Overall, these novel formulations may represent an efficient and safer MTM-delivering alternative for sarcoma treatment.

A novel bis(pyrazolyl)methane compound as a potential agent against Gram-positive bacteria.

This study was designed to propose alternative therapeutic compounds to fight against bacterial pathogens. Thus, a library of nitrogen-based compounds bis(triazolyl)methane (1T-7T) and bis(pyrazolyl)methane (1P-11P) was synthesised following previously reported methodologies and their antibacterial activity was tested using the collection strains of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Moreover, the novel compound 2P was fully characterized by IR, UV-Vis and NMR spectroscopy. To evaluate antibacterial activity, minimal inhibitory concentrations (MICs), minimal bactericidal concentrations (MBCs), minimum biofilm inhibitory concentrations (MBICs), and minimum biofilm eradication concentrations (MBECs) assays were carried out at different concentrations (2-2000 µg/mL). The MTT assay and Resazurin viability assays were performed in both human liver carcinoma HepG2 and human colorectal adenocarcinoma Caco-2 cell lines at 48 h. Of all the synthesised compounds, 2P had an inhibitory effect on Gram-positive strains, especially against S. aureus. The MIC and MBC of 2P were 62.5 and 2000 µg/mL against S. aureus, and 250 and 2000 µg/mL against E. faecalis, respectively. However, these values were > 2000 µg/mL against E. coli and P. aeruginosa. In addition, the MBICs and MBECs of 2P against S. aureus were 125 and > 2000 µg/mL, respectively, whereas these values were > 2000 µg/mL against E. faecalis, E. coli, and P. aeruginosa. On the other hand, concentrations up to 250 µg/mL of 2P were non-toxic doses for eukaryotic cell cultures. Thus, according to the obtained results, the 2P nitrogen-based compound showed a promising anti-Gram-positive effect (especially against S. aureus) both on planktonic state and biofilm, at non-toxic concentrations.

Novel Fluorescence Guanidine Molecules for Selective Sulfate Anion Detection in Water Complex Samples over a Wide pH Range.

Quantitative analysis of sulfate anions in water still remains an important challenge for the society. Among all the methodologies, the most successful one is based on optical supramolecular receptors because the presence of small concentrations of sulfate anion modifies the photophysical properties of the receptor. In this case, fluorescence anion sensors have been designed by the incorporation of guanidine motifs into fluorenyl cores. The photophysical behaviors of the new mono- (M) and bis-guanidine (B) derivatives were studied through pH dependence, solvent effects, and ion sensing on steady-state spectra and time-resolved fluorescence spectroscopy. In more detail, the results demonstrate that M is a highly selective and sensitive sulfate ion receptor in real water samples and, even more importantly, its function remains unchanged at different ranges of pH. The reason behind this resides on the fluorescence quenching produced by an internal charge-transfer process when the sulfate anion is complexed with M. It is worth noting that the global and partial affinity constants (1010 M-2 and 105 M-1, respectively) of complex formation are far above from the current sulfate sensors in water (104 M-1) which give an LOD of 0.10 µM in water with an analytical range of 2.5-10 µM. On the other hand, although it would seem, at first sight, that the B derivate will be the most promising one, the possibility of having two simultaneous protonation states reduces the complex formation and, therefore, its sensitivity to sulfate anions. The results presented here offer the possibility of using a new molecule in water environments, which opens the door to infinite applications such as the detection of trace amounts of sulfate ions in food or water.