Large pore (a = 150-200 A) wormlike and highly oriented cubic (IM3m space group) and 2D-hexagonal (P6m) mesostructured xerogels have been reproducibly synthesised by Evaporation-Induced Self Assembly (EISA). Mesostructure control was attained by changing the template (nonionic block copolymer) and water (h = [H2O]/[Si]) ratio.

BackgroundTamoxifen (Tam) is the most frequent treatment for estrogen receptor (ER) positive breast cancer. We recently showed that fibronectin (FN) leads to Tam resistance and selection of breast cancer stem cells. With the aim of developing a nanoformulation that would simultaneously tackle ER and FN/β1 integrin interactions, we designed polyethylene glycol-polycaprolactone polymersomes polymersomes (PS) that carry Tam and are functionalized with the tumor-penetrating iRGD peptide (iRGD-PS-Tam).ResultsPolyethylene glycol-polycaprolactone PS were assembled and loaded with Tam using the hydration film method. The loading of encapsulated Tam, measured by UPLC, was 2.4 ± 0.5 mol Tam/mol polymer. Physicochemical characterization of the PS demonstrated that iRGD functionalization had no effect on morphology, and a minimal effect on the PS size and polydispersity (176 nm and Pdi 0.37 for iRGD-TAM-PS and 171 nm and Pdi 0.36 for TAM-PS). iRGD-PS-Tam were taken up by ER+ breast carcinoma cells in 2D-culture and exhibited increased penetration of 3D-spheroids. Treatment with iRGD-PS-Tam inhibited proliferation and sensitized cells cultured on FN to Tam. Mechanistically, treatment with iRGD-PS-Tam resulted in inhibition ER transcriptional activity as evaluated by a luciferase reporter assay. iRGD-PS-Tam reduced the number of cells with self-renewing capacity, a characteristic of breast cancer stem cells. In vivo, systemic iRGD-PS-Tam showed selective accumulation at the tumor site.ConclusionsOur study suggests iRGD-guided delivery of PS-Tam as a potential novel therapeutic strategy for the management of breast tumors that express high levels of FN. Future studies in pre-clinical in vivo models are warranted.

Main group element coordination polymers (MGE-CPs) are important compounds for the development of multifunctional materials. However, there has been a shortage of studies regarding their structural, optical, catalytic, mechanical, and antibacterial properties. This work presents an exhaustive study of a set of crystalline MGE-CPs obtained from bismuth and indium metals and iminodiacetate, 1,2,4,5-benzenetetracarboxylate, and 2,2'-bipyridine as building blocks. An in-depth topological analysis of the networks was carried out. Additionally, nanoindentation studies were performed on two representative low-dimensional compounds in order to find the relationships between their structural features and their intrinsic mechanical properties (hardness and elasticity). The solid-state photoluminescence (SSPL) properties were also studied in terms of excitation, emission, lifetimes values, and CIE chromaticites. Moreover, the heterogeneous catalytic activities of the compounds were evaluated with the cyanosilylation reaction using a set of carbonylic substrates under solvent-free conditions. Finally, the inhibitory effect of the Bi-CPs on the growth of microorganisms such as Escherichia coli, Salmonella enterica serovar Typhimurium, and Pseudomonas aeruginosa, which are associated with relevant infectious diseases, is reported.

The coherent manipulation of acoustic waves on the nanoscale usually requires multilayers with thicknesses and interface roughness defined down to the atomic monolayer. This results in expensive devices with predetermined functionality. Nanoscale mesoporous materials present high surface-to-volume ratio and tailorable mesopores, which allow the incorporation of chemical functionalization to nanoacoustics. However, the presence of pores with sizes comparable to the acoustic wavelength is intuitively perceived as a major roadblock in nanoacoustics. Here we present multilayered nanoacoustic resonators based on mesoporous SiO 2 thin-films showing acoustic resonances in the 5-100 GHz range. We characterize the acoustic response of the system using coherent phonon generation experiments. Despite resonance wavelengths comparable to the pore size, we observe for the first time well-defined acoustic resonances. Our results open the path to a promising platform for nanoacoustic sensing and reconfigurable acoustic nanodevices based on soft, inexpensive fabrication methods.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Mesoporous titania thin film (MTTF)-based electrodes are vastly popular due to their versatility and their potential use as sensors, catalysts, and photovoltaic devices. For these applications, understanding of diffusion through the pores along the thickness of the films is critical. Cyclic voltammetry with the use of a freely diffusing redox probe is a promising and simple strategy for the characterization of this kind of modified electrodes. However, the application of a mesoporous insulating material on a flat electrode greatly modifies the diffusion regimes in the vicinity of the reaction zone. This makes the use of traditional tools for data interpretation, such as the Randles−S ̌evcǐ ́k equation, insufficient. In this work, the application of a model previously developed for partially covered electrodes (Matsuda et al., J. Electroanal. Chem. 1979, 101 (1), 29−38) is proposed to interpret experimental results. An excellent agreement between experimental and simulated voltammograms was achieved for MTTFs with different pore sizes and pore arrays. This analysis can be attributed to a lack of uniformity along the films related to differences in pore-to-pore connectivity within their thickness. At the same time, it is revealed that pore and neck sizes are determinant for diffusion within these materials. Thus, two dimensions govern the electrochemical results: nanopore sizes and arrays and microregions with different connectivities along the MTTF.

We present the study of the anchoring of carboxylic groups on SiO2 nanoparticles from different approximations based on the photochemical radical thiol-ene addition (PRTEA) reaction: a photografting approach between mercaptosuccinic acid (MSA) and vinyl-modified SiO2 nanoparticles and the post-grafting on the surface of silica colloids of the silane precursor 2-((2-(trimethoxysilyl)ethyl)thio)succinic acid (TMSMSA), obtained from the PRTEA. These synthetic strategies were compared with a widely common derivatization methodology based on the nucleophilic attack of surface-anchored amino groups with succinic anhydride. The successful functionalization of the colloidal silica was confirmed by infrared spectroscopy (FTIR), zeta potential at different pH and contact angle measurements. We found that although these three approaches were valid for -COOH immobilization, they had a noticeable impact on the dispersability and agglomeration of the colloidal suspension at the end of the synthesis. Scanning electron microscopy, dynamic light scattering (DLS) and fluorescence correlation spectroscopy (FCS) measurements indicated that the PRTEA photografting between MSA and vinyl-modified SiO2 resulted in highly dispersed colloidal particles. On the other hand, the presence of surface -COOH groups was highly beneficial for redispersion of the colloidal material after lyophilization or freeze-drying procedures.

In this work we report a novel paper-based analytical device read-out via LEDinduced fluorescence detection (FPAD) for the quantification of the emerging pollutant ethinylestradiol (EE2) in river water samples. The PAD was used as a reaction platform for a competitive enzyme immunoassay. For the PAD development, microzones of filter paper, printed by a wax printing method, were modified with amino-functionalized SBA-15 and subsequently, anti-EE2 specific antibodies were covalently immobilized.The determination of EE2 in water was carried out by adding a fixed concentration of EE2 conjugated with the enzyme horseradish peroxidase (HRP) to samples and standards. Then, the FPAD were added and incubated for 10 min. Finally, the detection was performed by the reaction of 10-acetyl-3,7-dihydroxyphenoxazine (ADHP) whose oxidation is catalyzed by HRP in the presence of H2O2, obtaining the highly fluorescent resorufin (R). Resorufin was detected by LED excitation at 550 nm, observing emission at 585 nm. The EE2 concentration in the samples was inversely proportional to the relative fluorescence obtained from the enzymatic reaction products. The FPAD assay showed a detection limit (LOD) of 0.05 ng L -1 and coefficients of variation (CV) below 4.5 % within-assay and below 6.5 % between-assay, respectively. The results obtained show the potential suitability of our FPAD for the selective and sensitive quantification of EE2 in river water samples. In addition, it has the PADs advantages of being disposable, easy to apply and inexpensive.