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Abstract Background Previous studies employing polymeric micelles and molecular imaging for in vivo nanosystem characterization have led to the development of radionanoprobes (RNPs) designed for diagnosing and monitoring therapeutic interventions in preclinical oncology research, specifically within breast and colon cancer models. These models exhibit high GLUT1 expression on tumor cells and VEGFR expression on the tumor vasculature. We aimed to enhance the tumor-targeting specificity of these RNPs by functionalizing micelles with glucose and bevacizumab. The choice of 99mTc to label the nanoprobes is based on its availability and that direct labeling method is a widespread strategy to prepare radiopharmaceuticals using cold reagents and a 99Mo/99mTc generator. Soluplus® is an attractive polymer for synthesizing micelles that also allows their functionalization. With all the above, the objective of this work was to design, develop and characterize nanoprobes based on polymeric micelles and radiolabeled with 99mTc for the characterization of biological processes associated to the diagnosis, prognosis and monitoring of animal models of breast and colon cancer in preclinical research using molecular images. Results Four RNPs ([99mTc]Tc-Soluplus®, [99mTc]Tc-Soluplus®+TPGS, [99mTc]Tc-Soluplus®+glucose and [99mTc]Tc-Soluplus®+bevacizumab) were produced with high radiochemical purity (> 95% in all cases) and stability in murine serum for up to 3 h. The RNPs maintained the 100 nm size of the Soluplus® polymeric micelles even when they were functionalized and labeled with 99mTc. The image acquisition protocol enabled the visualization of tumor uptake in two cancer experimental models using the assigned RNPs. In vivo biological characterization showed signal-to-background ratios of 1.7 ± 0.03 for [99mTc]Tc-Soluplus®+TPGS, 1.8 ± 0.02 for [99mTc]Tc-Soluplus®, and 2.3 ± 0.02 for [99mTc]Tc-Soluplus®+glucose in the breast cancer model, and 1.8 ± 0.04 for [99mTc]Tc-Soluplus® and 3.7 ± 0.07 for [99mTc]Tc-Soluplus®+bevacizumab in the colon cancer model. Ex vivo biodistribution, showed that the uptake of the tumors, regardless of the model, is

Background/Objective: World Health Organization latest statistics state that 17% of infectious diseases are transmitted by vectors, causing more than 700,000 deaths each year. Particularly, dengue (DENV), Zika (ZIKV) and yellow fever (YFV) viral infections have generated international awareness due to their epidemic proportion and risks of international spread. In this framework, the repositioning strategy of Efavirenz (EFV) represents a key clinical feature to improve different antiviral therapies. Therefore, the development of Soluplus®-based nanomicelles (NMs) loaded with EFV (10 mg/mL) for optimized oral pharmacotherapy against ZIKV, DENV and YFV infections was investigated. Methods: EFV-NMs were obtained by an acetone diffusion technique. Micellar size and in vitro micellar interaction with mucin were assessed by dynamic light scattering. In vitro cytocompatibility was investigated in A549 and Vero cells and micellar in vitro antiviral activity against ZIKV, DENV and YFV was evaluated. In vivo oral bioavailability and histological studies were assessed in Wistar rats. Results: EFV encapsulation within Soluplus® NMs increased the drug’s apparent aqueous solubility up to 4803-fold with a unimodal micellar size distribution and a micellar size of ~90 nm at 25 and 37 °C. Micellar in vitro interaction with mucin was also assessed in a pH range of 1.2–7.5 and its storage micellar physicochemical stability at 4 °C was confirmed over 2 years. In vitro cytocompatibility assays in A549 and Vero cells confirmed that EFV micellar dispersions resulted in safe nanoformulations. Interestingly, EFV-loaded NMs exhibited significantly higher in vitro antiviral activity compared with EFV solution for all the tested flaviviruses. In addition, the selectivity index (SI) values reveal that EFV-loaded NMs exhibited considerably more biological efficacy compared to EFV solution in A549 and Vero cell lines and for each viral infection (SI > 10). Further, the drug pharmacokinetics parameters were enhanced after the oral administration of EFV-loaded NMs, being biocompatible by not causing damage in the gastrointestinal segments. Conclusions: Overall, our EFV nanoformulation highlighted its potential as a novel drug delivery platform for optimized ZIKV, DENV and YFV antiviral therapy.

Abstract While cellular metabolism impacts the DNA damage response, a systematic understanding of the metabolic requirements that are crucial for DNA damage repair has yet to be achieved. Here, we investigate the metabolic enzymes and processes that are essential for the resolution of DNA damage. By integrating functional genomics with chromatin proteomics and metabolomics, we provide a detailed description of the interplay between cellular metabolism and the DNA damage response. Further analysis identified that Peroxiredoxin 1, PRDX1, contributes to the DNA damage repair. During the DNA damage response, PRDX1 translocates to the nucleus where it reduces DNA damage‐induced nuclear reactive oxygen species. Moreover, PRDX1 loss lowers aspartate availability, which is required for the DNA damage‐induced upregulation of de novo nucleotide synthesis. In the absence of PRDX1, cells accumulate replication stress and DNA damage, leading to proliferation defects that are exacerbated in the presence of etoposide, thus revealing a role for PRDX1 as a DNA damage surveillance factor.

Background/Objective: World Health Organization latest statistics state that 17% of infectious diseases are transmitted by vectors, causing more than 700,000 deaths each year. Particularly, dengue (DENV), Zika (ZIKV) and yellow fever (YFV) viral infections have generated international awareness due to their epidemic proportion and risks of international spread. In this framework, the repositioning strategy of Efavirenz (EFV) represents a key clinical feature to improve different antiviral therapies. Therefore, the development of Soluplus®-based nanomicelles (NMs) loaded with EFV (10 mg/mL) for optimized oral pharmacotherapy against ZIKV, DENV and YFV infections was investigated. Methods: EFV-NMs were obtained by an acetone diffusion technique. Micellar size and in vitro micellar interaction with mucin were assessed by dynamic light scattering. In vitro cytocompatibility was investigated in A549 and Vero cells and micellar in vitro antiviral activity against ZIKV, DENV and YFV was evaluated. In vivo oral bioavailability and histological studies were assessed in Wistar rats. Results: EFV encapsulation within Soluplus® NMs increased the drug's apparent aqueous solubility up to 4803-fold with a unimodal micellar size distribution and a micellar size of ~90 nm at 25 and 37 °C. Micellar in vitro interaction with mucin was also assessed in a pH range of 1.2–7.5 and its storage micellar physicochemical stability at 4 °C was confirmed over 2 years. In vitro cytocompatibility assays in A549 and Vero cells confirmed that EFV micellar dispersions resulted in safe nanoformulations. Interestingly, EFV-loaded NMs exhibited significantly higher in vitro antiviral activity compared with EFV solution for all the tested flaviviruses. In addition, the selectivity index (SI) values reveal that EFV-loaded NMs exhibited considerably more biological efficacy compared to EFV solution in A549 and Vero cell lines and for each viral infection (SI > 10). Further, the drug pharmacokinetics parameters were enhanced after the oral administration of EFV-loaded NMs, being biocompatible by not causing damage in the gastrointestinal segments. Conclusions: Overall, our EFV nanoformulation highlighted its potential as a novel drug delivery platform for optimized ZIKV, DENV and YFV antiviral therapy. [ABSTRACT FROM AUTHOR]

Prime Editing is a versatile genome engineering tool. Here, the authors identify the DNA repair pathway known as mismatch repair as inhibitory for Prime Editing, thus, loss of mismatch repair enhances the efficiency of Prime Editing.

Background: Ursodeoxycholic acid (UDCA) is a therapeutic agent used for the treatment of cholestatic hepatobiliary diseases in pediatric patients. It is a bile acid that presents high lipophilicity, and it belongs to Class II of the Biopharmaceutical Classification System (BCS), which exhibits low water solubility and high intestinal permeability, which leads to poor oral absorption. The objective of this work was to design and optimize UDCA nanosuspensions by means of the precipitation-ultrasonication method to improve the solubility, dissolution, and oral bioavailability of UDCA. Methods: A three-level, three-factor Box–Behnken design was used to optimize formulation variables and obtain uniform, small-particle-size UDCA nanosuspensions. The independent variables were: stabilizer percentage (X1), amplitude (X2), and sonication time (X3), and the dependent variable was the particle size (Y1). In the precipitation–ultrasonication method, UDCA was dissolved in acetone:PEG 400 (1:1 v/v) and quickly incorporated into the antisolvent (pre-cooled aqueous dispersion of HPMC E-15 0.3%), by means of intense sonication at 50 W for 5 min, controlling temperature through an ice water bath. The lyophilization efficacy was evaluated by means of a cryoprotective efficacy test, working with 10% maltose at −80 °C. The nanosuspensions were characterized by dynamic light scattering (DLS), X-ray diffraction, and scanning electron microscopy (SEM). The physicochemical stability was determined at 25 °C and 4 °C at 7, 14, 30, and 60 days, and the UDCA content was analyzed via HPLC-UV. An in vitro dissolution assay and an oral bioavailability study were performed in male Wistar rats. Results: A significant impact was achieved in the optimized nanosuspension with 0.3% (stabilizer), 50 W (amplitude), and 5 min (sonication time), with a particle size of 352.4 nm, PDI of 0.11, and zeta potential of −4.30 mV. It presented adequate physicochemical stability throughout the study and the UDCA content was between 90% and 110%. In total, 86% of UDCA was dissolved in the in vitro dissolution test. The relative oral bioavailability was similar without significant statistical differences when comparing the lyophilized nanosuspension and the commercial tablet, the latter presenting a more erratic behavior. The pharmacokinetic parameters of the nanosuspension and the commercial tablet were Tmax (1.0 ± 0.9 h vs. 2.0 ± 0.8 h, respectively), Cmax (0.558 ± 0.118 vs. 0.366 ± 0.113 µM, respectively), ΔCmax (0.309 ± 0.099 vs. 0.232 ± 0.056, respectively), AUC (4.326 ± 0.471 vs. 2.188 ± 0.353 µg/mL.h, respectively, p < 0.02), and IAUC0–24h (2.261 ± 0.187 µg/mL.h vs. 1.924 ± 0.440 µg/mL.h, respectively). Conclusions: The developed nanosuspension presents an appropriate dosage and administration for pediatric patients. On the other hand, it exhibits an adequate absorption and UDCA oral bioavailability.

Background: Previous studies employing polymeric micelles and molecular imaging for in vivo nanosystem characterization have led to the development of radionanoprobes (RNPs) designed for diagnosing and monitoring therapeutic interventions in preclinical oncology research, specifically within breast and colon cancer models. These models exhibit high GLUT1 expression on tumor cells and VEGFR expression on the tumor vasculature. We aimed to enhance the tumor-targeting specificity of these RNPs by functionalizing micelles with glucose and bevacizumab. The choice of 99mTc to label the nanoprobes is based on its availability and that direct labeling method is a widespread strategy to prepare radiopharmaceuticals using cold reagents and a 99Mo/99mTc generator. Soluplus® is an attractive polymer for synthesizing micelles that also allows their functionalization. With all the above, the objective of this work was to design, develop and characterize nanoprobes based on polymeric micelles and radiolabeled with 99mTc for the characterization of biological processes associated to the diagnosis, prognosis and monitoring of animal models of breast and colon cancer in preclinical research using molecular images. Results: Four RNPs ([99mTc]Tc-Soluplus®, [99mTc]Tc-Soluplus®+TPGS, [99mTc]Tc-Soluplus®+glucose and [99mTc]Tc-Soluplus®+bevacizumab) were produced with high radiochemical purity (> 95% in all cases) and stability in murine serum for up to 3 h. The RNPs maintained the 100 nm size of the Soluplus® polymeric micelles even when they were functionalized and labeled with 99mTc. The image acquisition protocol enabled the visualization of tumor uptake in two cancer experimental models using the assigned RNPs. In vivo biological characterization showed signal-to-background ratios of 1.7 ± 0.03 for [99mTc]Tc-Soluplus®+TPGS, 1.8 ± 0.02 for [99mTc]Tc-Soluplus®, and 2.3 ± 0.02 for [99mTc]Tc-Soluplus®+glucose in the breast cancer model, and 1.8 ± 0.04 for [99mTc]Tc-Soluplus® and 3.7 ± 0.07 for [99mTc]Tc-Soluplus®+bevacizumab in the colon cancer model. Ex vivo biodistribution, showed that the uptake of the tumors, regardless of the model, is < 2% IA/g while the blood activity concentration is higher, suggesting that the enhanced permeability and retention effect (EPR) would be one of the mechanisms involved in imaging tumors in addition to the active targeting of RNPs. Conclusions: Soluplus®-based polymeric micelles provide a promising nanotechnological platform for the development of RNPs. The functionalization with glucose and bevacizumab enhances tumor specificity enabling effective imaging and monitoring of cancer in animal models. [ABSTRACT FROM AUTHOR]

Cisplatin induces DNA crosslinks that are highly cytotoxic. Hence, platinum complexes are frequently used in the treatment of a broad range of cancers. Efficiency of cisplatin treatment is limited by the tumor-specific DNA damage response to the generated lesions. We reasoned that better tools to investigate the repair of DNA crosslinks induced by cisplatin would therefore be highly useful in addressing drug limitations. Here, we synthesized a series of cisplatin derivatives that are compatible with click chemistry, thus allowing visualization and isolation of DNA-platinum crosslinks from cells to study cellular responses. We prioritized one alkyne and one azide Pt(II) derivative, Pt-alkyne-53 and Pt-azide-64, for further biological characterization. We demonstrate that both compounds bind DNA and generate DNA lesions and that the viability of treated cells depends on the active DNA repair machinery. We also show that the compounds are clickable with both a fluorescent probe as well as biotin, thus they can be visualized in cells, and their ability to induce crosslinks in genomic DNA can be quantified. Finally, we show that Pt-alkyne-53 can be used to identify DNA repair proteins that bind within its proximity to facilitate its removal from DNA. The compounds we report here can be used as valuable experimental tools to investigate the DNA damage response to platinum complexes and hence might shed light on mechanisms of chemoresistance.

Se evaluó la dinámica de contaminación biológica en una microcuenca con uso ganadero de la Pampa Ondulada de Argentina, mediante el coeficiente de partición bacteriano (BactKdQ) del modelo SWAT (Soil and Water Assessment Tool). Se simularon escenarios de contaminación para dos cargas ganaderas (0,5 y 1 equivalente vaca por ha), utilizando dos valores de BactKdQ: el propuesto por el SWAT (175 m3 Mg-1) y uno real medido in situ (10 m3 Mg-1). Para el escenario real se corroboró la íntima relación entre los eventos de precipitaciones - escurrimientos y la contaminación biológica de los cursos de agua. Los valores reales de BactKdQ, aún siendo bajos, incidieron de forma significativa en la dinámica de transporte de coliformes fecales. Por ende, es de interés la inclusión de parámetros como el BactKdQ medidos localmente y no de aquellos que el modelo SWAT incluye por defecto. Además, se pudo observar una importante concentración de coliformes fecales en la microcuenca, señalándola como un ambiente de alto riesgo de contaminación biológica, ya que para esta aplicación del SWAT todos los niveles guías fueron sobrepasados. Este trabajo destaca la relevancia de la utilización de modelos computacionales como soporte de decisiones productivas y ambientales.

We have previously demonstrated significant in vitro natriuretic effects of anandamide (AEA) nanoformulation in polymeric nanoparticles, whose size prevents their accumulation in organs, such as the kidneys. Therefore, it is of particular interest to design and test nanostructures that can pharmacologically accumulate in these organs. In this regard, we prepared and characterized polymeric nanomicelles (~14 and 40 nm). Likewise, their biodistribution was determined. Spontaneously hypertensive rats (SHR) and normotensive rats (WKY), n = 3 per group, were divided into five treatment conditions: control, sham, free AEA freshly dispersed in aqueous solution or 24 h after its dispersion, and AEA encapsulated in nanomicelles. The kidneys were the main site of accumulation of the nanoformulation after 24 h. Freshly dispersed free AEA showed its classical triphasic response in SHR, which was absent from all other treatments. Nanoformulated AEA produced a sustained antihypertensive effect over 2 h, accompanied by a significant increase in fractional sodium excretion (FSE %). These effects were not observed in WKY, sham, or free AEA-treated rats after 24 h of its aqueous dispersion. Without precedent, we demonstrate in vivo natriuretic, diuretic, and hypotensive effects of AEA nanoformulation in polymeric nanomicelles, suggesting its possible use as a new antihypertensive agent with intravenous administration and passive renal accumulation.

Los ríos y arroyos de zonas rurales de la Provincia de Buenos Aires contienen concentraciones variables de metales pesados y glifosato. En el presente estudio se evaluó la toxicidad de los metales Cu, Pb y Zn, el herbicida glifosato (producto activo y formulación ATANOR®) y sus mezclas binarias, en dos especies de algas verdes (una estándar [Raphidocelis subcapitata] y una cepa autóctona de Scenedesmus acutus aislada del Arroyo Burgos, Buenos Aires). Los bioensayos se realizaron en un rango de concentración entre 0.5 mg/L y 20 mg/L, y a los 7 días de incubación se estimó la densidad algal. Para obtener las concentraciones efectivas que inhiben el 10, 20 y 50% del crecimiento (CE10, CE20 y CE50) de cada sustancia individual y de las mezclas mediante un ajuste no lineal se modeló el porcentaje de inhibición del crecimiento (%I) en función de cada concentración. Según las CE50 obtenidas, la toxicidad del Cu y del Zn fue mayor en R. subcapitata (7.47±2.14 y 6.51±2.26 mg/L, respectivamente) que en S. acutus (10.90±3.75 y >20 mg/L). El Pb y el glifosato no resultaron tóxicos para ninguna de las dos cepas. El glifosato ATANOR® fue tóxico solamente para R. subcapitata (CE50=12.00±3.10 mg/L). Según los valores de CE10 y CE20 de las sustancias individuales y de las mezclas binarias, la cepa S. acutus resultó más sensible. Teniendo en cuenta las unidades tóxicas (UT) obtenidas, se evidenció que las mezclas Cu+Zn, Cu+glifosato ATANOR® y Zn+glifosato ATANOR® presentaron efectos antagónicos sobre R. subcapitata (según valores de UT obtenidos a partir de las CE20 y CE50), mientras que las mezclas Cu+Pb y Cu+Zn tuvieron efectos sinérgicos y antagónicos, respectivamente, sobre S. acutus (según valores de UT obtenidos a partir de las CE20). Este estudio destaca la importancia de realizar bioensayos con sustancias tóxicas utilizando cepas algales autóctonas que permiten inferir efectos potenciales en las comunidades y tramas tróficas nativas.

Among respiratory infections, tuberculosis was the second deadliest infectious disease in 2020 behind COVID-19. Inhalable nanocarriers offer the possibility of actively targeting anti-tuberculosis drugs to the lungs, especially to alveolar macrophages (cellular reservoirs of the Mycobacterium tuberculosis). Our strategy was based on the development of a mannose-decorated micellar nanoformulation based in Soluplus® to co-encapsulate rifampicin and curcumin. The former is one of the most effective anti-tuberculosis first-line drugs, while curcumin has demonstrated potential anti-mycobacterial properties. Mannose-coated rifampicin (10 mg/mL)–curcumin (5 mg/mL)-loaded polymeric micelles (10% w/v) demonstrated excellent colloidal properties with micellar size ~108 ± 1 nm after freeze-drying, and they remain stable under dilution in simulated interstitial lung fluid. Drug-loaded polymeric micelles were suitable for drug delivery to the deep lung with lung accumulation, according to the in vitro nebulization studies and the in vivo biodistribution assays of radiolabeled (99mTc) polymeric micelles, respectively. Hence, the nanoformulation did not exhibit hemolytic potential. Interestingly, the addition of mannose significantly improved (5.2-fold) the microbicidal efficacy against Mycobacterium tuberculosis H37Rv of the drug-co-loaded systems in comparison with their counterpart mannose-free polymeric micelles. Thus, this novel inhaled nanoformulation has demonstrated its potential for active drug delivery in pulmonary tuberculosis therapy.

Abstract EXD2 is a recently identified exonuclease that has been implicated in nuclear double-strand break repair. Given our long standing interest in mitochondrial DNA maintenance and indications that EXD2 could also be a mitochondrial protein we sought to determine its cellular localization and possible mitochondrial associated functions. Our results show that EXD2 indeed shows mitochondrial localization, but, surprisingly, is found predominantly associated with the mitochondrial outer-membrane. Gradient purified nuclei show only the faintest hint of EXD2 presence while overexpression of the predicted full-length protein shows exclusive mitochondrial localization. Importantly, induction of double-strand DNA breaks via X-irradiation or Zeocin treatment does not support the notion that EXD2 re-locates to the nucleus following double-strand breaks and thus is unlikely to have a direct role in nuclear DNA repair. Knockdown or overexpression of EXD2 affects the cellular distribution of mitochondria. These results suggest that the reported defects in nuclear DNA repair following EXD2 depletion are likely an indirect consequence of altered mitochondrial dynamics and/or function.