Magnetic-driven Interleukin-4 internalization promotes magnetic nanoparticle morphology and size-dependent macrophage polarization

Macrophages are known to depict two major phenotypes: classically activated macrophages (M1), associated with high production of pro-inflammatory cytokines, and alternatively activated macrophages (M2), which present an anti-inflammatory function. A precise control over M1-M2 polarization is a promising strategy in therapeutics to modulate both tissue regeneration and tumor progression processes. However, this is not a simple task as macrophages behave differently depending on the microenvironment. In agreement with this, non-consistent data have been reported regarding macrophages response to magnetic iron oxide nanoparticles (MNPs). To investigate the impact of both tissue microenvironment and MNPs properties on the obtained macrophage responses, single-core (SC) and multi-core (MC) citrate coated MNPs, are synthesized and, afterwards, loaded with a macrophage polarization trigger, IL-4. The developed MNPs are then tested in macrophages subjected to different stimuli. We demonstrate that macrophages treated with low concentrations of MNPs behave differently depending on the polarization stage independently of the concentration of iron. Moreover, we find out that MNPs size and morphology determines the effect of the IL-4 loaded MNPs on M1 macrophages, since IL-4 loaded SC MNPs favor the polarization of M1 macrophages towards M2 phenotype, while IL-4 loaded MC MNPs further stimulate the secretion of pro-inflammatory cytokines.

LED-driven photo-Fenton process for micropollutant removal by nanostructured magnetite anchored in mesoporous silica

The presence of organic micropollutants in water bodies represents a threat to living organisms and ecosystems due to their toxicological effects and recalcitrance in conventional wastewater treatments. In this context, the application of heterogeneous photo-Fenton based on magnetite nanoparticles supported on mesoporous silica (SBA15) is proposed to carry out the non-specific degradation of the model compounds ibuprofen, carbamazepine, hormones, bisphenol A and the dye ProcionRed®. The operating conditions (i.e., pH, catalyst load and hydrogen peroxide concentration) were optimized by Response Surface Methodology (RSM). The paramagnetic properties of the nanocatalysts allowed their repeated use in sequential batch operations with catalyst losses below 1%. The feasibility of the process was demonstrated as removal rates above 90% after twelve accomplished after twelve consecutive cycles. In addition, the contributions of different reactive oxygen species, mainly •OH, were analyzed together with the formation of by-products, achieving total mineralization values of 15% on average.

Correction: Rivas et al. Tendon-Derived Mesenchymal Stem Cells (TDSCs) as an In Vitro Model for Virological Studies in Wild Birds. Viruses 2023, 15, 1455

In the original publication [...].

Magnetic separation and concentration of Aβ 1-42 molecules dispersed at the threshold concentration for Alzheimer's disease diagnosis in clinically-relevant volumes of sample

BACKGROUND

Alzheimer's disease (AD) is the leading cause of dementia and loss of autonomy in the elderly, implying a progressive cognitive decline and limitation of social activities. The progressive aging of the population is expected to exacerbate this problem in the next decades. Therefore, there is an urgent need to develop quantitative diagnostic methodologies to assess the onset the disease and its progression especially in the initial phases.

RESULTS

Here we describe a novel technology to extract one of the most important molecular biomarkers of AD (Aβ1-42) from a clinically-relevant volume - 100 µl - therein dispersed in a range of concentrations critical for AD early diagnosis. We demonstrate that it is possible to immunocapture Aβ1-42 on 20 nm wide magnetic nanoparticles functionalized with hyperbranced KVLFF aptamers. Then, it is possible to transport them through microfluidic environments to a detection system where virtually all (~ 90%) the Aβ1-42 molecules are concentrated in a dense plug of ca.50 nl. The technology is based on magnetic actuation by permanent magnets, specifically designed to generate high gradient magnetic fields. These fields, applied through submillimeter-wide channels, can concentrate, and confine magnetic nanoparticles (MNPs) into a droplet with an optimized shape that maximizes the probability of capturing highly diluted molecular biomarkers. These advancements are expected to provide efficient protocols for the concentration and manipulation of molecular biomarkers from clinical samples, enhancing the accuracy and the sensitivity of diagnostic technologies.

CONCLUSIONS

This easy to automate technology allows an efficient separation of AD molecular biomarkers from volumes of biological solutions complying with the current clinical protocols and, ultimately, leads to accurate measurements of biomarkers. The technology paves a new way for a quantitative AD diagnosis at the earliest stage and it is also adaptable for the biomarker analysis of other pathologies.

Tendon-Derived Mesenchymal Stem Cells (TDSCs) as an In Vitro Model for Virological Studies in Wild Birds

The use of wild animals in research is complicated due to the capture and housing conditions, as well as to legal aspects, making it difficult to develop in vivo and in vitro models for the study of pathologies that affect these species. Here we validate an in vitro model of tendon-derived mesenchymal cells (TDSC) from Eurasian blackbird (Turdus merula) cadaveric samples. Through the expression of surface markers and the ability to differentiate into multiple lineages, the nature of the cells was confirmed. We then evaluated Mesenchymal Stem Cells (MSCs) as an infection model for the Usutu Flavivirus. To this aim, blackbird TDSCs were compared to Vero E6 cells, commonly used in Flavivirus studies. Both cells showed permissiveness to USUV infection as confirmed by immunocytochemistry. Moreover, TDSCs exhibited replication kinetics similar to, although slightly lower than, Vero E6, confirming these cells as a pertinent study model for the study of the pathogenesis of USUV. In this work, we isolated and characterized tendon-derived mesenchymal stem cells, which represent an interesting and convenient in vitro model for the study of wildlife species in laboratories.

Organotypic Hippocampal Slice Cultures from Adult Tauopathy Mice and Theragnostic Evaluation of Nanomaterial Phospho-TAU Antibody-Conjugates

Organotypic slice culture models surpass conventional in vitro methods in many aspects. They retain all tissue-resident cell types and tissue hierarchy. For studying multifactorial neurodegenerative diseases such as tauopathies, it is crucial to maintain cellular crosstalk in an accessible model system. Organotypic slice cultures from postnatal tissue are an established research tool, but adult tissue-originating systems are missing, yet necessary, as young tissue-originating systems cannot fully model adult or senescent brains. To establish an adult-originating slice culture system for tauopathy studies, we made hippocampal slice cultures from transgenic 5-month-old hTau.P301S mice. In addition to the comprehensive characterization, we set out to test a novel antibody for hyperphosphorylated TAU (pTAU, B6), with and without a nanomaterial conjugate. Adult hippocampal slices retained intact hippocampal layers, astrocytes, and functional microglia during culturing. The P301S-slice neurons expressed pTAU throughout the granular cell layer and secreted pTAU to the culture medium, whereas the wildtype slices did not. Additionally, cytotoxicity and inflammation-related determinants were increased in the P301S slices. Using fluorescence microscopy, we showed target engagement of the B6 antibody to pTAU-expressing neurons and a subtle but consistent decrease in intracellular pTAU with the B6 treatment. Collectively, this tauopathy slice culture model enables measuring the extracellular and intracellular effects of different mechanistic or therapeutic manipulations on TAU pathology in adult tissue without the hindrance of the blood-brain barrier.

Versatile magnetic configuration for the control and manipulation of superparamagnetic nanoparticles

The control and manipulation of superparamagnetic nanoparticles (SP-MNP) is a significant challenge and has become increasingly important in various fields, especially in biomedical research. Yet, most of applications rely on relatively large nanoparticles, 50 nm or higher, mainly due to the fact that the magnetic control of smaller MNPs is often hampered by the thermally induced Brownian motion. Here we present a magnetic device able to manipulate remotely in microfluidic environment SP-MNPs smaller than 10 nm. The device is based on a specifically tailored configuration of movable permanent magnets. The experiments performed in 500 µm capillary have shown the ability to concentrate the SP-MNPs into regions characterized by different shapes and sizes ranging from 100 to 200 µm. The results are explained by straightforward calculations and comparison between magnetic and thermal energies. We provide then a comprehensive description of the magnetic field intensity and its spatial distribution for the confinement and motion of magnetic nanoparticles for a wide range of sizes. We believe this description could be used to establish accurate and quantitative magnetic protocols not only for biomedical applications, but also for environment, food, security, and other areas.

Role of Dipolar Interactions on the Determination of the Effective Magnetic Anisotropy in Iron Oxide Nanoparticles

Challenging magnetic hyperthermia (MH) applications of immobilized magnetic nanoparticles require detailed knowledge of the effective anisotropy constant (K_eff ) to maximize heat release. Designing optimal MH experiments entails the precise determination of magnetic properties, which are, however, affected by the unavoidable concurrence of magnetic interactions in common experimental conditions. In this work, a mean-field energy barrier model (ΔE), accounting for anisotropy (E_A ) and magnetic dipolar (E_D ) energy, is proposed and used in combination with AC measurements to a specifically developed model system of spherical magnetic nanoparticles with well-controlled silica shells, acting as a spacer between the magnetic cores. This approach makes it possible to experimentally demonstrate the mean field dipolar interaction energy prediction with the interparticle distance, d_ij , E_D ≈ 1/d_ij ³ and obtain the E_A as the asymptotic limit for very large d_ij . In doing so, K_eff uncoupled from interaction contributions is obtained for the model system (iron oxide cores with average sizes of 8.1, 10.2, and 15.3 nm) revealing to be 48, 23, and 11 kJ m^-3 , respectively, close to bulk magnetite/maghemite values and independent from the specific spacing shell thicknesses selected for the study.

Synthesis and Characterization of a Biocompatible Nanoplatform Based on Silica-Embedded SPIONs Functionalized with Polydopamine

Superparamagnetic iron oxide nanoparticles (SPIONs) have gained increasing interest in nanomedicine, but most of those that have entered the clinical trials have been withdrawn due to toxicity concerns. Therefore, there is an urgent need to design low-risk and biocompatible SPION formulations. In this work, we present an original safe-by-design nanoplatform made of silica nanoparticles loaded with SPIONs and decorated with polydopamine (SPIONs@SiO2-PDA) and the study of its biocompatibility performance by an ad hoc thorough in vitro to in vivo nanotoxicological methodology. The results indicate that the SPIONs@SiO₂-PDA have excellent colloidal stability in serum-supplemented culture media, even after long-term (24 h) exposure, showing no cytotoxic or genotoxic effects in vitro and ex vivo. Physiological responses, evaluated in vivo using Caenorhabditis elegans as the animal model, showed no impact on fertility and embryonic viability, induction of an oxidative stress response, and a mild impact on animal locomotion. These tests indicate that the synergistic combination of the silica matrix and PDA coating we developed effectively protects the SPIONs, providing enhanced colloidal stability and excellent biocompatibility.

Genetic diversity of Bovine Viral Diarrhea Virus in cattle in France between 2018 and 2020

Bovine Viral Diarrhea Virus (BVDV) is one of the main pathogens that affects ruminants worldwide, generating significant economic losses. Like other RNA viruses, BVDV is characterized by a high genetic variability, generating the emergence of new variants, and increasing the risk of new outbreaks. The last report on BVDV genotypes in France was in 2008, since which there have been no new information. The goal of this study is to determine the genetic diversity of BVDV strains currently circulating in France. To this aim, samples of cattle were taken from different departments that are part of the main areas of livestock production during the years 2018 to 2020. Using the partial sequence of the 5'UTR region of the viral genome, we identified and classified 145 samples corresponding to Pestivirus A and one sample corresponding to Pestivirus D. For the Pestivirus A samples, the 1e, 1b, 1d, and 1l genotypes, previously described in France, were identified. Next, the 1r and 1s genotypes, not previously described in the country, were detected. In addition, a new genotype was identified and was tentatively assigned as 1x genotype. These results indicate an increase in the genetic diversity of BVDV in France.

Exploiting the Potential of Supported Magnetic Nanomaterials as Fenton-Like Catalysts for Environmental Applications

In recent years, the application of magnetic nanoparticles as alternative catalysts to conventional Fenton processes has been investigated for the removal of emerging pollutants in wastewater. While this type of catalyst reduces the release of iron hydroxides with the treated effluent, it also presents certain disadvantages, such as slower reaction kinetics associated with the availability of iron and mass transfer limitations. To overcome these drawbacks, the functionalization of the nanocatalyst surface through the addition of coatings such as polyacrylic acid (PAA) and their immobilization on a mesoporous silica matrix (SBA15) can be factors that improve the dispersion and stability of the nanoparticles. Under these premises, the performance of the nanoparticle coating and nanoparticle-mesoporous matrix binomials in the degradation of dyes as examples of recalcitrant compounds were evaluated. Based on the outcomes of dye degradation by the different functionalized nanocatalysts and nanocomposites, the nanoparticles embedded in a mesoporous matrix were applied for the removal of estrogens (E1, E2, EE2), accomplishing high removal percentages (above 90%) after the optimization of the operational variables. With the feasibility of their recovery in mind, the nanostructured materials represented a significant advantage as their magnetic character allows their separation for reuse in different successive sequential batch cycles.

The Sick Adipose Tissue: New Insights Into Defective Signaling and Crosstalk With the Myocardium

Adipose tissue (AT) biology is linked to cardiovascular health since obesity is associated with cardiovascular disease (CVD) and positively correlated with excessive visceral fat accumulation. AT signaling to myocardial cells through soluble factors known as adipokines, cardiokines, branched-chain amino acids and small molecules like microRNAs, undoubtedly influence myocardial cells and AT function via the endocrine-paracrine mechanisms of action. Unfortunately, abnormal total and visceral adiposity can alter this harmonious signaling network, resulting in tissue hypoxia and monocyte/macrophage adipose infiltration occurring alongside expanded intra-abdominal and epicardial fat depots seen in the human obese phenotype. These processes promote an abnormal adipocyte proteomic reprogramming, whereby these cells become a source of abnormal signals, affecting vascular and myocardial tissues, leading to meta-inflammation, atrial fibrillation, coronary artery disease, heart hypertrophy, heart failure and myocardial infarction. This review first discusses the pathophysiology and consequences of adipose tissue expansion, particularly their association with meta-inflammation and microbiota dysbiosis. We also explore the precise mechanisms involved in metabolic reprogramming in AT that represent plausible causative factors for CVD. Finally, we clarify how lifestyle changes could promote improvement in myocardiocyte function in the context of changes in AT proteomics and a better gut microbiome profile to develop effective, non-pharmacologic approaches to CVD.

Effect of mesoporous silica and its combination with hydroxyapatite on the regeneration of rabbit's bone defects: A pilot study

BACKGROUND

Bone volume augmentation is a routine technique used in oral implantology and periodontology. Advances in the surgical techniques and the biomaterials field have allowed a greater accessibility to these treatments. Nevertheless, dehiscence and fenestrations incidence during dental implant procedures are still common in patients with bone loss.

OBJECTIVE

The main objective is to evaluate in a pilot experimental study the biological response to mesoporous silica (MS) hybrid scaffolds and its regenerative capacity in different formulations.

METHODS

Two defects per rabbit tibia were performed (one for control and other for test) and the biomaterials tested in this study have been used to fill the bone defects, prepared in two different formulations (3D hybrid scaffolds or powdered material, in 100% pure MS form, or 50% MS with 50% hydroxyapatite (HA). Euthanasia was performed 4 months after surgery for bone histopathological study and radiographic images were acquired by computerized microtomography.

RESULTS

Results showed that radiographically and histopathologically pure MS formulations lead to a lower biological response, e.g when formulated with HA, the osteogenic response in terms of osteoconduction was greater.

CONCLUSIONS

We observed tolerance and lack of toxicity of the MS and HA, without registering any type of local or systemic allergic reaction.

Controlling the structure and photocatalytic properties of three—dimensional aerogels obtained by simultaneous reduction and self-assembly of BiOI/GO aqueous colloidal dispersions

Water pollution affects all living habitats, since it is the most basic element that sustains all life forms and, as an exceptional solvent, it readily makes any compound available for living cells, either nutrients or noxious substances. Elimination of molecular contaminants from water quality is one of the most challenging technical problems that conventional treatments like flocculation and filtration fail short to defeat. Particulate photocatalysts, used to degrade contaminants, have the main drawback of their recovery from the water matrices. The inclusion of photocatalytic nanoparticles (NPs) into a large supporting framework, is presented as an innovative approach aiming to ensure a facile separation from water. To this end, three-dimensional (3D) aerogels with photocatalytic properties were prepared by a simple and scalable method based on the reduction—induced self-assembly of graphene oxide (GO) in the presence of BiOI nanoparticles. With the help of ascorbic acid, as a green reducing agent, partial reduction of GO into reduced graphene oxide (RGO) and self-assembly of both kinds of nanostructures into a porous monolith was achieved. BiOI doped RGO aerogels were further stabilized and morphologically controlled using poly (ethylene glycol) as stabilizer. The photocatalytic performance of these aerogels was evaluated by following the discoloration of methylene blue (MB) solution, under visible light irradiation, showing that structure and dispersion degree of NPs to be fundamental variables. Hence, this methodology is proposed to produce hybrid aerogels with controlled morphology and photocatalytic performance that has the potential to be used in water cleaning procedures.

Versatile Mesoporous Nanoparticles for Cell Applications

Mesoporous silica nanostructures are emerging as a promising platform able to deal with challenges of many different applications in fields such as biomedicine and nanotechnology. The versatile physical and functional properties of these materials like high specific surface area, ordered porosity, chemical stability under temperature and pH variations, and biocompatible performance, offers new approaches to many biomedical applications ranging from drug delivery systems to biosensing, cell applications and tissue engineering. Their morphology, size and textural properties can be easily tailored by means of chemical control, giving rise to a variety of nanostructures with hexagonal (SBA15, MCM41) or cubic (SBA16) arrangement of channels and pore size ranging from 1.3 to 10 nm. Based on the versatility of their silane surface, a plethora of hybrid mesoporous matrices can be prepared incorporating new functionalities like contrast enhancement for magnetic resonance imaging, magnetic/plasmonic hyperthermia, drug delivery or cell applications by the simple grafting of superparamagnetic metal oxides (Fe₃O₄, transition metal ferrites) nanoparticles, noble metal (Au, Ag) nanoparticles, fluorescent moieties (fluorescein, rhodamine) or biological agents (mAb, mRNA, etc). The goal of this work is to present the development, by a facile soft template method, of size tailored mesoporous silica nanospheres from 20 to 350 nm (by means of chemical control), and highlight its versatility for surface grafting (with rhodamine and polydopamine) and their biological compatibility and efficient uptake by cultured HeLa cells. The combined, physicochemical and biological, properties indicate that MSNs are good candidates for cell tagging, gene transfer or targeted therapies.

Biocompatible magnetic gelatin nanoparticles with enhanced MRI contrast performance prepared by single-step desolvation method

Magnetic nanoparticles are versatile materials that have boosted the development of different biomedical applications, being superparamagnetic magnetite nanoparticles a milestone in the field, after achieving clinical approval as contrast agents in magnetic resonance imaging (Feridex®), magnetic hyperthermia agents for oncological treatments (NanoTherm®), or iron deficiency supplement (Feraheme®). However, its potential as theragnostic agent could be further expanded by its encapsulation within a biodegradable hydrogel, capable of enhancing the biocompatibility and loading abilities, to simultaneously carry drugs, radiotracers, or biomolecules. Gelatin, is a natural biopolymer with optimal in vivo feature and gelling capacity that has been extensively used for decades in pharmaceuticals. In this work, we have addressed the preparation of gelatin nanoparticles, bare and loaded with magnetite nanoparticles, with controlled size to be used as contrast agents in magnetic resonance imaging. The main formulation parameters influencing the preparation of gelatin nanoparticles with controlled size by single-step desolvation method, were studied and optimized, to produce small gelatin nanoparticles (97nm) and highly loaded (38% w/w) Fe3O4@citrate gelatin nanoparticles (150 nm) with high magnetic response (65emus/g). The viability assays of the magnetic gelatin nanoparticles, tested with mesenchymal stem cells, showed negligible toxicity and in vitro magnetic resonance imaging tests, performed in agar phantoms, revealed a good contrast for T2 weighting MRI, r2 = 265.5(mM−1 s−1), superior to commercial products, such as Resovist or Endorem.

Hybrid mesoporous nanostructured scaffolds as dielectric biosimilar restorative materials

BACKGROUND

The intricate structure of natural materials is in correspondence with its highly complex functional behaviour. The health of teeth depends, in a complex way, on a heterogeneous arrangement of soft and hard porous tissues that allow for an adequate flow of minerals and oxygen to provide continuous restoration. Although restorative materials, used in clinics, have been evolving from the silver amalgams to actual inorganic fillers, their structural and textural properties are scarcely biomimetic, hindering the functional recovery of the tissue.

OBJECTIVE

The objective of this work is to compare and test the hybrid mesoporous silica-based scaffolds as candidates for dentine restoration applications.

METHODS

In this work, we present the development and the physical properties study of biocompatible hybrid mesoporous nanostructured scaffolds with a chemically versatile surface and biosimilar architecture. We test their textural (BET) and dielectric permittivity (ac impedance) properties.

RESULTS

These materials, with textural and dielectric properties similar to dentine and large availability for the payload of therapeutic agents, are promising candidates as functional restorative materials, suitable for impedance characterization techniques in dental studies.

CONCLUSIONS

Structural, textural, morphological characterization and electrical properties of hybrid mesoporous show a large degree of similarity to natural dentin samples.

53 Effect of anthocyanin supplementation in bovine pre-implantation embryonic development during invitro maturation of oocytes

Oocyte protection against reactive oxygen species (ROS) during invitro maturation (IVM) may play a decisive role in pre-implantation embryonic development. For instance, anthocyanins have shown greater antioxidant effects than vitamins C and E. The objective of this study was to determine the anthocyanin supplementation level that influences quantity and quality of bovine blastocysts development during IVM. Cumulus–oocyte complexes (COC) were recovered from 185 abattoir ovaries in 6 sessions and classified (Grade 1 and 2) for maturation. Oocytes were in IVM in commercial medium (Vitrogen®) supplemented with anthocyanin (pelargonidin chloride) at different concentrations: 0 (control), 1, 10, 20, and 40μM, in droplets of 70μL with 12 to 15 COC at 38.5°C, 5% CO2 and 90% humidity for 22to 24h. Sperm selection was performed by Percoll gradient method (45/90%) with centrifugation at 600×g for 6min. The final concentration for IVF was 2×106 sperm mL−1. A total of 462 oocytes were used in the experiment (6 replicates). Presumptive zygotes were invitro cultured (IVC) in commercial medium (Vitrogen) in droplets of 70µL with 12–15 zygotes at 38°C, 5% CO2, and 90% humidity until the blastocyst stage (Day 7 of culture). The cleavage (Day 2), morulae (Day 4), and blastocyst (Day 7) rates were measured during IVC. The data were processed with non-parametric tests (Kruskal–Wallis test with independent samples, P<0.05) using IBM SPSS Statistics 2.0 for Windows. The results in the control group of cleavage, morulae, and blastocyst rates were 67.3, 27.0, and 22.1%, respectively. Although, numerically, anthocyanin at 1μM resulted in a higher blastocyst rate (28.8%) and anthocyanin at 10μM resulted in a greater number of blastocysts of advanced stages (65.0%), anthocyanin supplementation during IVM did not influence the quantity and quality of bovine blastocyst development (P>0.05). In conclusion, the supplementation of anthocyanin to the maturation medium did not affect invitro development of bovine embryos. Complementary studies at the cellular and gene expression level may be required.

61 Swim-up and microfluidic techniques improve the kinetic parameters of selected bovine spermatozoa for invitro fertilization: Preliminary results

For invitro embryo production, spermatozoa with fertilizing capacity must possess optimal kinetic, morphometric, vitality, and DNA integrity characteristics. The objective of this study was to evaluate the effect of 3 sperm selection methods on sperm quality and invitro embryonic development in bovine. Frozen commercial semen (0.5 mL/straws) from one bull with known fertility was thawed at 37°C for 20s and was divided for 3 sperm selection techniques: density gradient, swim-up, and microfluidic sperm sorting. The sperm kinetic parameters (VCL=curvilinear velocity, VSL=straight line velocity, VAP=average path velocity, ALH=lateral displacement of sperm head, BCF=beat frequency cross, STR=path straightness) were assessed using computer-assisted sperm analysis (CASA). Sperm morphometric parameters were evaluated using Diff-Quick staining followed by automated analysis. To assess vitality, the sperm were stained with propidium iodide and acridine orange, then analysed under a fluorescence microscope. In addition, DNA fragmentation was assessed using sperm chromatin dispersion method. Last, the fertilizing capacity of the selected sperm was tested by fertilizing cumulus–oocyte complexes (2×106 sperm mL−1) obtained from slaughterhouse ovaries and matured invitro for 24h. A standardized invitro embryo production protocol was used with commercial medium from Vitrogen. The cleavage rate and blastocyst yield were measured on Day 2 and 7, respectively (fertilization=Day 0). The results were calculated with analysis of variance and Tukey’s test (P<0.05). The values of sperm kinetic parameters obtained with swim-up (VCL 132.5µm/s; VSL 73.5µm/s) and microfluidic technique (VCL 129.5µm/s; VSL 64.4µm/s) were significantly higher (P<0.05) than those obtained by density gradient (VCL 98.3µm/s; VSL 45.01µm/s). However, the total and progressive motility by density gradient method was slightly higher (89% and 57%) compared with that assessed by swim-up (64% and 43%) or microfluidic technique (74% and 54%) respectively. Microfluidic sorting (11.3%) showed lower (P<0.05) DNA fragmentation levels compared with density gradient method (16.6%), whereas the swim-up technique (12.5%) was similar between both groups. No significant difference was detected between the 3 groups for sperm morphometric and vitality parameters. Moreover, cleavage rates were similar (P>0.05) between the 3 sperm selection techniques: density gradient (84.0%), swim-up (75.2%), and microfluidic sorting (67.3%). However, blastocyst yield was significantly higher (P<0.05) using sperm selected by density gradient (28.1%) and swim-up (21.9%) compared with microfluidic sorting (15.3%). In conclusion, sperm selection using microfluidic and swim-up techniques improved kinetic parameters with lower levels of DNA fragmentation, without affecting sperm morphometry. However, both the density gradient and swim-up techniques are efficient systems for producing invitro bovine embryo.

Iron oxide-mediated photo-Fenton catalysis in the inactivation of enteric bacteria present in wastewater effluents at neutral pH

The pressure on natural water resources associated with increasing water scarcity highlights the value of using reclaimed water through the development of efficient and environmentally friendly treatment technologies. In this work, the use of magnetic nanoparticles in photo-Fenton catalysis for water disinfection was considered to inactivate natural enteric bacteria present in municipal wastewater effluents under white light and neutral pH. The most recommended ranges were evaluated in key variables such as the loading and composition of nanoparticles (NPs), hydrogen peroxide (H₂O₂) concentration, the light source (UV and visible) and treatment time were evaluated in wastewater disinfection expressed in terms of total coliforms and Escherichia coli colony forming units (CFU). The magnetic separation of NPs allowed the disinfection process to be carried out in different cycles, facilitating the recovery of the nanocatalyst and avoiding its discharge with the treated effluent.

Magnetic nanostructures for marine and freshwater toxins removal

Marine and freshwater toxins contaminate water resources, shellfish and aquaculture products, causing a broad range of toxic effects in humans and animals. Different core-shell nanoparticles were tested as a new sorbent for removing marine and freshwater toxins from liquid media. Water solutions were contaminated with 20 μg/L of marine toxins and up to 50 μg/L of freshwater toxins and subsequently treated with 250 or 125 mg/L of nanoparticles. Under these conditions, carbon nanoparticles removed around 70% of saxitoxins, spirolides, and azaspiracids, and up to 38% of diarrheic shellfish poisoning toxins. In the case of freshwater toxins, the 85% of microcystin LR was eliminated; other cyclic peptide toxins were also removed in a high percentage. Marine toxins were adsorbed in the first 5 min of contact, while for freshwater toxins it was necessary 60 min to reach the maximum adsorption. Toxins were recovered by extraction from nanoparticles with different solvents. Gymnodinium catenatum, Prorocentrum lima, and Microcystis aeruginosa cultures were employed to test the ability of nanoparticles to adsorb toxins in a real environment, and the same efficacy to remove toxins was observed in these conditions. These results suggest the possibility of using the nanotechnology in the treatment of contaminated water or in chemical analysis applications.

Carbon-Coated Superparamagnetic Nanoflowers for Biosensors Based on Lateral Flow Immunoassays

Superparamagnetic iron oxide nanoflowers coated by a black carbon layer (Fe3O4@C) were studied as labels in lateral flow immunoassays. They were synthesized by a one-pot solvothermal route, and they were characterized (size, morphology, chemical composition, and magnetic properties). They consist of several superparamagnetic cores embedded in a carbon coating holding carboxylic groups adequate for bioconjugation. Their multi-core structure is especially efficient for magnetic separation while keeping suitable magnetic properties and appropriate size for immunoassay reporters. Their functionality was tested with a model system based on the biotin-neutravidin interaction. For this, the nanoparticles were conjugated to neutravidin using the carbodiimide chemistry, and the lateral flow immunoassay was carried out with a biotin test line. Quantification was achieved with both an inductive magnetic sensor and a reflectance reader. In order to further investigate the quantifying capacity of the Fe3O4@C nanoflowers, the magnetic lateral flow immunoassay was tested as a detection system for extracellular vesicles (EVs), a novel source of biomarkers with interest for liquid biopsy. A clear correlation between the extracellular vesicle concentration and the signal proved the potential of the nanoflowers as quantifying labels. The limit of detection in a rapid test for EVs was lower than the values reported before for other magnetic nanoparticle labels in the working range 0-3 × 107 EVs/μL. The method showed a reproducibility (RSD) of 3% (n = 3). The lateral flow immunoassay (LFIA) rapid test developed in this work yielded to satisfactory results for EVs quantification by using a precipitation kit and also directly in plasma samples. Besides, these Fe3O4@C nanoparticles are easy to concentrate by means of a magnet, and this feature makes them promising candidates to further reduce the limit of detection.

Usutu Virus Infection of Embryonated Chicken Eggs and a Chicken Embryo-Derived Primary Cell Line

Usutu virus (USUV) is a mosquito-borne flavivirus, closely related to the West Nile virus (WNV). Similar to WNV, USUV may cause infections in humans, with occasional, but sometimes severe, neurological complications. Further, USUV can be highly pathogenic in wild and captive birds and its circulation in Europe has given rise to substantial avian death. Adequate study models of this virus are still lacking but are critically needed to understand its pathogenesis and virulence spectrum. The chicken embryo is a low-cost, easy-to-manipulate and ethically acceptable model that closely reflects mammalian fetal development and allows immune response investigations, drug screening, and high-throughput virus production for vaccine development. While former studies suggested that this model was refractory to USUV infection, we unexpectedly found that high doses of four phylogenetically distinct USUV strains caused embryonic lethality. By employing immunohistochemistry and quantitative reverse transcriptase-polymerase chain reaction, we demonstrated that USUV was widely distributed in embryonic tissues, including the brain, retina, and feather follicles. We then successfully developed a primary cell line from the chorioallantoic membrane that was permissive to the virus without the need for viral adaptation. We believe the future use of these models would foster a significant understanding of USUV-induced neuropathogenesis and immune response and allow the future development of drugs and vaccines against USUV.

KCTD5, a novel TRPM4-regulatory protein required for cell migration as a new predictor for breast cancer prognosis

Transient receptor potential melastatin 4 (TRPM4) is a Ca²⁺ -activated nonselective cationic channel that regulates cell migration and contractility. Increased TRPM4 expression has been related to pathologies, in which cytoskeletal rearrangement and cell migration are altered, such as metastatic cancer. Here, we identify the K⁺ channel tetramerization domain 5 (KCTD5) protein, a putative adaptor of cullin3 E3 ubiquitin ligase, as a novel TRPM4-interacting protein. We demonstrate that KCTD5 is a positive regulator of TRPM4 activity by enhancing its Ca²⁺ sensitivity. We show that through its effects on TRPM4 that KCTD5 promotes cell migration and contractility. Finally, we observed that both TRPM4 and KCTD5 expression are increased in distinct patterns in different classes of breast cancer tumor samples. Together, these data support that TRPM4 activity can be regulated through expression levels of either TRPM4 or KCTD5, not only contributing to increased understanding of the molecular mechanisms involved on the regulation of these important ion channels, but also providing information that could inform treatments based on targeting these distinct molecules that define TRPM4 activity.

Tribological Behavior of Nanolubricants Based on Coated Magnetic Nanoparticles and Trimethylolpropane Trioleate Base Oil

The main task of this work is to study the tribological performance of nanolubricants formed by trimethylolpropane trioleate (TMPTO) base oil with magnetic nanoparticles coated with oleic acid: Fe₃O₄ of two sizes 6.3 nm and 10 nm, and Nd alloy compound of 19 nm. Coated nanoparticles (NPs) were synthesized via chemical co-precipitation or thermal decomposition by adsorption with oleic acid in the same step. Three nanodispersions of TMPTO of 0.015 wt% of each NP were prepared, which were stable for at least 11 months. Two different types of tribological tests were carried out: pure sliding conditions and rolling conditions (5% slide to roll ratio). With the aim of analyzing the wear by means of the wear scar diameter (WSD), the wear track depth and the volume of the wear track produced after the first type of the tribological tests, a 3D optical profiler was used. The best tribological performance was found for the Nd alloy compound nanodispersion, with reductions of 29% and 67% in friction and WSD, respectively, in comparison with TMPTO. On the other hand, rolling conditions tests were utilized to study friction and film thickness of nanolubricants, determining that Fe₃O₄ (6.3 nm) nanolubricant reduces friction in comparison to TMPTO.

Cubic Anisotropic Co- and Zn-Substituted Ferrite Nanoparticles as Multimodal Magnetic Agents

The use of magnetic nanoparticles as theranostic agents for the detection and treatment of cancer diseases has been extensively analyzed in the last few years. In this work, cubic-shaped cobalt and zinc-doped iron oxide nanoparticles with edge lengths in the range from 28 to 94 nm are proposed as negative contrast agents for magnetic resonance imaging and to generate localized heat by magnetic hyperthermia, obtaining high values of transverse relaxation coefficients and specific adsorption rates. The applied magnetic fields presented suitable characteristics for the potential validation of the results into the clinical practice in all cases. Pure iron oxide and cobalt- and zinc-substituted ferrites have been structurally and magnetically characterized, observing magnetite as the predominant phase and weak ferrimagnetic behavior at room temperature, with saturation values even larger than those of bulk magnetite. The coercive force increased due to the incorporation of cobalt ions, while zinc substitution promotes a significant increase in saturation magnetization. After their transfer to aqueous solution, those particles showing the best properties were chosen for evaluation in in vitro cell models, exhibiting high critical cytotoxic concentrations and high internalization degrees in several cell lines. The magnetic behavior of the nanocubes after their successful cell internalization was analyzed, detecting negligible variations on their magnetic hysteresis loops and a significant decrease in the specific adsorption rate values.

Making sense of parameter estimation and model simulation in bioprocesses

Most articles that report fitted parameters for kinetic models do not include meaningful statistical information. This study demonstrates the importance of reporting a complete statistical analysis and shows a methodology to perform it, using functionalities implemented in computational tools. As an example, alginate production is studied in a batch stirred-tank fermenter and modeled using the kinetic model proposed by Klimek and Ollis (1980). The model parameters and their 95% confidence intervals are estimated by nonlinear regression. The significance of the parameters value is checked using a hypothesis test. The uncertainty of the parameters is propagated to the output model variables through prediction intervals, showing that the kinetic model of Klimek and Ollis (1980) can simulate with high certainty the dynamic of the alginate production process. Finally, the results obtained in other studies are compared to show how the lack of statistical analysis can hold back a deeper understanding about bioprocesses.

Eficiencia técnica en sistemas de producción con bovinos de doble propósito

El sistema de producción con bovinos de doble propósito (SPDP) ha sido desarrollado en las zonas tropicales, caracterizado por bajos niveles de eficiencia, aspecto que requiere del análisis de los factores que la afectan. En el presente estudio se analizó la eficiencia técnica (ET) en 271 unidades de producción ubicadas en el estado Zulia, Venezuela, empleando una función de producción de frontera estocástica. Se utilizó como output los ingresos totales ($), y los inputs superficie (ha), unidades animales (UA), unidad trabajo hombre (UTH), y los costos totales ($). Se obtuvo un valor medio de eficiencia técnica de 66,63 %, con un rango de 19,74 a 99,62, lo que indica que existe un amplio margen de mejora. En el modelo de ineficiencia las variables carga animal (UA/ha), y los litros de leche por hectárea (L/ha) fueron significativas, el coeficiente presentó un signo positivo para la carga animal, lo que quiere decir que en la medida que aumenta este parámetro las explotaciones incrementan su ineficiencia, mientras que para los L/ha ocurrió lo contrario. Con base en estos resultados, se plantea la necesidad de determinar el efecto que ejercen las tecnologías de gestión del pastoreo sobre la ET, esto permitiría promover estrategias de manejo que tiendan a optimizar el uso del recurso forrajero, y de esta forma alcanzar mejores niveles de ET en los SPDP.

Development of Superparamagnetic Nanoparticles Coated with Polyacrylic Acid and Aluminum Hydroxide as an Efficient Contrast Agent for Multimodal Imaging

Early diagnosis of disease and follow-up of therapy is of vital importance for appropriate patient management since it allows rapid treatment, thereby reducing mortality and improving health and quality of life with lower expenditure for health care systems. New approaches include nanomedicine-based diagnosis combined with therapy. Nanoparticles (NPs), as contrast agents for in vivo diagnosis, have the advantage of combining several imaging agents that are visible using different modalities, thereby achieving high spatial resolution, high sensitivity, high specificity, morphological, and functional information. In this work, we present the development of aluminum hydroxide nanostructures embedded with polyacrylic acid (PAA) coated iron oxide superparamagnetic nanoparticles, Fe₃O₄@Al(OH)₃, synthesized by a two-step co-precipitation and forced hydrolysis method, their physicochemical characterization and first biomedical studies as dual magnetic resonance imaging (MRI)/positron emission tomography (PET) contrast agents for cell imaging. The so-prepared NPs are size-controlled, with diameters below 250 nm, completely and homogeneously coated with an Al(OH)₃ phase over the magnetite cores, superparamagnetic with high saturation magnetization value (Ms = 63 emu/g-Fe₃O₄), and porous at the surface with a chemical affinity for fluoride ion adsorption. The suitability as MRI and PET contrast agents was tested showing high transversal relaxivity (r₂) (83.6 mM^-1 s^-1) and rapid uptake of ¹⁸F-labeled fluoride ions as a PET tracer. The loading stability with ¹⁸F-fluoride was tested in longitudinal experiments using water, buffer, and cell culture media. Even though the stability of the ¹⁸F-label varied, it remained stable under all conditions. A first in vivo experiment indicates the suitability of Fe₃O₄@Al(OH)₃ nanoparticles as a dual contrast agent for sensitive short-term (PET) and high-resolution long-term imaging (MRI).

P1930Pharmacodynamic effects of vorapaxar as an add-on antiplatelet therapy in patients with and without diabetes mellitus: the optimizing anti-platelet therapy in diabetes mellitus (OPTIMUS)-5 study

Background

Vorapaxar (Vora) is a protease-activated receptor (PAR)-1 inhibitor which when added to dual antiplatelet therapy (DAPT) in patients with a history of myocardial infarction (MI) or with peripheral arterial (PAD) reduces thrombotic cardiovascular events at the expense of increased bleeding. The efficacy of Vora is enhanced in patients with diabetes mellitus (DM) compared to non-DM. However, the differential pharmacodynamic (PD) effects of Vora in DM vs non-DM patients are unknown. Moreover, although withdrawal of aspirin has emerged as a strategy to reduce bleeding when adjunctive antithrombotic therapies are used, the PD effects of Vora after stopping aspirin in DAPT treated patients is unknown.

Purpose

To assess the PD effects of Vora in addition to standard DAPT as well as in combination with clopidogrel following aspirin withdrawal in patients with and without DM.

Methods

This was a prospective parallel-design PD study conducted in post-MI or PAD patients with and without DM. Patients on DAPT with aspirin (81mg/qd) and clopidogrel (75mg/qd) were divided in two groups according to DM status. Each cohort was treated with Vora (2.5mg/qd) in addition to DAPT (i.e., triple therapy) for 30 days and afterwards stopped aspirin and maintained treatment with Vora plus clopidogrel (i.e., dual therapy) for other 30 days. PD testing using 5 different assays was conducted at 3 time-points: baseline (while on DAPT); after 30 days of triple therapy; after 30 days of dual therapy. The primary endpoint was the non-inferiority of CAT (Collagen-ADP-TRAP)-induced aggregation, a marker of global platelet reactivity, of Vora plus clopidogrel (dual therapy) vs Vora plus DAPT (triple therapy).

Results

The PD population was composed of a total of 64 patients (DM, n=30; non-DM, n=34). Although adding Vora to DAPT significantly reduced CAT-induced aggregation, stopping aspirin was associated with an increase in CAT-induced aggregation in both DM (mean difference=12; 95% CI: 3 to 21; p=0.010) and non-DM (mean difference=10; 95% CI: 4 to 16; p=0.003), thus not meeting the primary endpoint of non-inferiority (Figure). The magnitude of such increase was higher in DM compared with non-DM (p=0.036). Although Vora abolished TRAP-induced aggregation in both DM and non-DM patients, it did not affect markers of clot kinetics including speed of thrombin generation. Aspirin withdrawal was associated with a marked increase in makers sensitive to cyclooxygenase-1 (COX-1) blockade; markers of P2Y12 signaling were higher in DM compared to not DM after aspirin withdrawal.

CAT-induced aggregation

Conclusion

Adjunctive treatment with Vora reduces platelet-mediated thrombogenicity without affecting clot kinetics in both DM and non-DM patients while on DAPT. However, platelet-mediated thrombogenicity is increased after aspirin withdrawal, a phenomenon which is enhanced in DM patients underscoring the pivotal contribution of the COX-1 signaling pathway in these high risk patients.

Acknowledgement/Funding

The study was supported in part by an investigator initiated study grant from Merck

P1934Platelet inhibitory profiles of prasugrel versus ticagrelor in patients with CYP2C19 loss-of-function genotypes undergoing percutaneous coronary intervention: results of a randomized feasibility study

Background

Although clopidogrel is the most widely used P2Y12 inhibitor, loss-of-function (LOF) allelic variants located within the hepatic cytochrome P450 (CYP) 2C19 gene lead to attenuated bioactivation, increased rates of high platelet reactivity (HPR), and worse outcomes in patients undergoing percutaneous coronary intervention (PCI). Drug regulating authorities have suggested using alternative P2Y12 inhibitors (i.e., prasugrel or ticagrelor) in these patients. However, tailoring antiplatelet therapy in clinical practice according to results of genetic testing has been limited due to lack of access to promptly available results. Moreover, there are no head-to-head pharmacodynamic (PD) comparisons of prasugrel vs ticagrelor among patients with CYP2C19 LOF alleles.

Purpose

The aim of this study was to evaluate the feasibility of using rapid genetic testing in clinical practice and to compare the PD effects of prasugrel vs ticagrelor in patients undergoing PCI with CYP2C19 LOF alleles.

Methods

This was a prospective, randomized study conducted in patients with stable coronary artery disease and non-ST elevation acute coronary syndrome scheduled for left heart catheterization (LHC) with the intent to undergo PCI. Patients underwent rapid genetic testing using the Spartan RX assay, which defines CYP2C19 genetic status within 1 hour, allowing patients to be genotyped the same day of their LHC. Patients who were carriers of at least one LOF (*2 or *3) allele were randomized to receive either prasugrel [60mg loading dose (LD) - 10mg/day maintenance dose (MD)] or ticagrelor (180mg LD - 90mg b.i.d MD). Blood samples for PD analysis by VerifyNow were collected at 5 time points: baseline (prior to PCI), 30 minutes, 2 hours, 24 hours (or at hospital discharge whichever came first), and 1–4 weeks post-LD. All patients were treated with aspirin. The primary endpoint of our study was the non-inferiority in platelet reactivity, measured as PRU, at 24 hours of prasugrel vs ticagrelor in LOF allele carriers.

Results

A total of 781 consecutive patients scheduled for LHC were genotyped, of whom 223 (28.5%) were carriers of at least one LOF. Of these, 65 patients underwent PCI and randomized to prasugrel (n=32) vs ticagrelor (n=33). PRU levels at 24 hours were 33 vs 36 (prasugrel vs ticagrelor; mean difference = −3; 95% CI: −28 to 22; p=0.814) meeting the primary endpoint of non-inferiority. Both prasugrel and ticagrelor significantly reduced PRU to a similar extent with no differences between groups at all other time points (Figure). Accordingly, HPR rates were low and similar between groups.

PRU by VerifyNow

Conclusion

Rapid genetic testing using the Spartan assay is feasible providing results in a timely fashion in a real-world clinical practice of patients undergoing PCI. Among patients with CYP2C19 LOF carrier status, prasugrel and ticagrelor are associated with similar levels of platelet inhibition.

Acknowledgement/Funding

Genetic testing was provided by Spartan RX

Multicatalysis Combining 3D-Printed Devices and Magnetic Nanoparticles in One-Pot Reactions: Steps Forward in Compartmentation and Recyclability of Catalysts

A tricatalytic compartmentalized system that immobilizes metallic species to perform one-pot sequential functionalization is described: a three-dimensional (3D)-printed palladium monolith, ferritic copper(I) magnetic nanoparticles, and a 3D-printed polypropylene capsule-containing copper(II) loaded onto polystyrene-supported 1,5,7-triazabicyclo[4.4.0]dec-5-ene (PS-TBD) allowed the rapid synthesis of diverse substituted 1-([1,1'-biphenyl]-4-yl)-1H-1,2,3-triazoles. The procedure is based on the Chan-Lam azidation/copper alkyne-azide cycloaddition/Suzuki reaction strategy in the solution phase. This catalytic system enabled the efficient assembly of the final compounds in high yields without the need for special additives or intermediate isolation. The monolithic catalyst-containing immobilized palladium species was synthesized by surface chemical modification of a 3D-printed silica monolith using a soluble polyimide resin as a key reagent, thus creating an extremely robust composite. All three immobilized catalysts described here were easily recovered and reused in numerous cycles. This work exemplifies the role of 3D printing in the design and manufacture of devices for compartmented multicatalytic systems to carry out complex one-pot transformations.

Complex I and II are required for normal mitochondrial Ca2+ homeostasis

Cytosolic calcium (_cCa²⁺) entry into mitochondria is facilitated by the mitochondrial membrane potential (ΔΨm), an electrochemical gradient generated by the electron transport chain (ETC). Is has been assumed that as long as mutations that affect the ETC do not affect the ΔΨm, the mitochondrial Ca²⁺ (_mCa²⁺) homeostasis remains normal. We show that knockdown of NDUFAF3 and SDHB reduce ETC activity altering _mCa²⁺ efflux and influx rates while ΔΨm remains intact. Shifting the equilibrium toward lower [Ca²⁺]_m accumulation renders cells resistant to death. Our findings reveal an unexpected relationship between complex I and II with the _mCa²⁺ homeostasis independent of ΔΨm.

A TR(i)P to Cell Migration: New Roles of TRP Channels in Mechanotransduction and Cancer

Cell migration is a key process in cancer metastasis, allowing malignant cells to spread from the primary tumor to distant organs. At the molecular level, migration is the result of several coordinated events involving mechanical forces and cellular signaling, where the second messenger Ca²⁺ plays a pivotal role. Therefore, elucidating the regulation of intracellular Ca²⁺ levels is key for a complete understanding of the mechanisms controlling cellular migration. In this regard, understanding the function of Transient Receptor Potential (TRP) channels, which are fundamental determinants of Ca²⁺ signaling, is critical to uncovering mechanisms of mechanotransduction during cell migration and, consequently, in pathologies closely linked to it, such as cancer. Here, we review recent studies on the association between TRP channels and migration-related mechanotransduction events, as well as in the involvement of TRP channels in the migration-dependent pathophysiological process of metastasis.

Detoxification agents based on magnetic nanostructured particles as a novel strategy for mycotoxin mitigation in food

Mycotoxins are toxic compounds that can be present in feed, food and beverages. In this work, 25 magnetic nanostructured materials were developed to remove the main types of mycotoxins from liquid food matrices. The efficiency for binding mycotoxins from contaminated aqueous solutions was studied. Nanocomposites (diameters lower to 15 μm) composed of mixtures of activated carbon, bentonite and aluminium oxide were able to eliminate up to 87% of mycotoxins with an adsorption efficiency of 450 µg/g. On the other hand, spheres with sizes below 3 mm and composed by biopolymers and activated carbon or graphene oxide removed up to 70% of mycotoxins (adsorption of 598 ng/g). These particles were tested for beer detoxification, and spheres composed of alginate and activated carbon or pectin maintain the ability to eliminate toxins from this beverage. Hence, this technology could be a useful tool for the food industry.

Insight into antibiotics removal: Exploring the photocatalytic performance of a Fe3O4/ZnO nanocomposite in a novel magnetic sequential batch reactor

The purpose of this research was the preparation and photocatalytic evaluation of a novel nanocomposite (NC) based on Fe₃O₄/ZnO, to eliminate four persistent antibiotics in surface waters: sulfamethoxazole, trimethoprim, erythromycin and roxithromycin. Prior to the operation of the photocatalytic reactor, the influence of pH (3-9), catalyst concentration (50-800 mg L^-1), oxidant dose (0-100 mg L^-1) and concentration of different targets (10-100 μg L^-1) on the catalytic efficiency was evaluated. The analysis of reaction kinetics showed that degradation processes of the four antibiotics followed a pseudo-first-order kinetic model. Antibiotics adsorption onto the nanocomposite surface depended on their electrostatic nature and played an important role when decreasing the initial concentration of antibiotics. In this context, kinetic rates were higher at lower initial levels of organic pollutants, which is a favourable effect from a practical application perspective. On the other hand, a synergistic effect of the available Fe in the nanocomposite was found, contributing to the oxidation of antibiotics by photo-Fenton as a secondary reaction. Then, a magnetic photocatalytic reactor was operated under optimal conditions. The enhanced photonic efficiency of Fe₃O₄/ZnO in the system, as well as the ease of the magnetic separation and catalyst reusability, indicate the viability of this reactor configuration.

Multifunctional Superparamagnetic Stiff Nanoreservoirs for Blood Brain Barrier Applications

Neurological diseases (Alzheimer's disease, Parkinson's disease, and stroke) are becoming a major concern for health systems in developed countries due to the increment of ageing in the population, and many resources are devoted to the development of new therapies and contrast agents for selective imaging. However, the strong isolation of the brain by the brain blood barrier (BBB) prevents not only the crossing of pathogens, but also a large set of beneficial drugs. Therefore, an alternative strategy is arising based on the anchoring to vascular endothelial cells of nanoplatforms working as delivery reservoirs. In this work, novel injectable mesoporous nanorods, wrapped by a fluorescent magnetic nanoparticles envelope, are proposed as biocompatible reservoirs with an extremely high loading capacity, surface versatility, and optimal morphology for enhanced grafting to vessels during their diffusive flow. Wet chemistry techniques allow for the development of mesoporous silica nanostructures with tailored properties, such as a fluorescent response suitable for optical studies, superparamagnetic behavior for magnetic resonance imaging MRI contrast, and large range ordered porosity for controlled delivery. In this work, fluorescent magnetic mesoporous nanorods were physicochemical characterized and tested in preliminary biological in vitro and in vivo experiments, showing a transversal relaxivitiy of 324.68 mM-1 s-1, intense fluorescence, large specific surface area (300 m² g-1), and biocompatibility for endothelial cells' uptake up to 100 µg (in a 80% confluent 1.9 cm² culture well), with no liver and kidney disability. These magnetic fluorescent nanostructures allow for multimodal MRI/optical imaging, the allocation of therapeutic moieties, and targeting of tissues with specific damage.

Double-stranded RNA production and the kinetics of recombinant Escherichia coli HT115 in fed-batch culture

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dsRNA production was growth-associated according to Luedeking-Piret model.

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dsRNA/biomass yield was 0.06 g g⁻¹, the same value in bacth and fed-batch culture.

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dsRNA productivity was 37% higher in fed-batch fermentation.

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Production of dsRNA occurred while the bacteria were actively multiplying.

Double-stranded RNA can induce interference processes. The specificity of this system raises the possibility of using dsRNA for therapeutic applications targeting viral diseases. Escherichia coli HT115 (DE3) has been widely used to produce dsRNA; however, the kinetics of dsRNA production and the relationship between dsRNA and biomass remain unknown. Our aims were to study the kinetics of dsRNA production and to improve dsRNA productivity with fed-batch technology. The results revealed that the production of dsRNA was growth-associated. In batch fermentation, the dsRNA/biomass yield remained close to 0.06 g·g⁻¹, with a maximum productivity of 11.1 mg l⁻¹ h⁻¹ at 10 h of culture. In fed-batch fermentation, the yield was 0.06 g g⁻¹, with a maximum dsRNA productivity of 15.2 mg l⁻¹ h⁻¹ at the end of the feed (12 h). Therefore, to increase the production of dsRNA, it is necessary to enhance the biomass that produces the recombinant nucleic acid.

Silver Atomic Quantum Clusters of Three Atoms for Cancer Therapy: Targeting Chromatin Compaction to Increase the Therapeutic Index of Chemotherapy

Nanomaterials with very low atomicity deserve consideration as potential pharmacological agents owing to their very small size and to their properties that can be precisely tuned with minor modifications to their size. Here, it is shown that silver clusters of three atoms (Ag3 -AQCs)-developed by an ad hoc method-augment chromatin accessibility. This effect only occurs during DNA replication. Coadministration of Ag3 -AQCs increases the cytotoxic effect of DNA-acting drugs on human lung carcinoma cells. In mice with orthotopic lung tumors, the coadministration of Ag3 -AQCs increases the amount of cisplatin (CDDP) bound to the tumor DNA by fivefold without modifying CDDP levels in normal tissues. As a result, CDDP coadministered with Ag3 -AQCs more strongly reduces the tumor burden. Evidence of the significance of targeting chromatin compaction to increase the therapeutic index of chemotherapy is now provided.

Orthogonal Clickable Iron Oxide Nanoparticle Platform for Targeting, Imaging, and On-Demand Release

A versatile iron oxide nanoparticle platform is reported that can be orthogonally functionalized to obtain highly derivatized nanomaterials required for a wide variety of applications, such as drug delivery, targeted therapy, or imaging. Facile functionalization of the nanoparticles with two ligands containing isocyanate moieties allows for high coverage of the surface with maleimide and alkyne groups. As a proof-of-principle, the nanoparticles were subsequently functionalized with a fluorophore as a drug model and with biotin as a targeting ligand towards tumor cells through Diels-Alder and azide-alkyne cycloaddition reactions, respectively. The thermoreversibility of the Diels-Alder product was exploited to induce the on-demand release of the loaded molecules by magnetic hyperthermia. Additionally, the nanoparticles were shown to target cancer cells through in vitro experiments, as analyzed by magnetic resonance imaging.