Decellularization of xenografted tumors provides cell-specific in vitro 3D environment

In vitro cell culture studies are common in the cancer research field, and reliable biomimetic 3D models are needed to ensure physiological relevance. In this manuscript, we hypothesized that decellularized xenograft tumors can serve as an optimal 3D substrate to generate a top-down approach for in vitro tumor modeling. Multiple tumor cell lines were xenografted and the formed solid tumors were recovered for their decellularization by several techniques and further characterization by histology and proteomics techniques. Selected decellularized tumor xenograft samples were seeded with the HCC1806 human triple-negative breast cancer (TNBC) basal-like subtype cell line, and cell behavior was compared among them and with other control 2D and 3D cell culture methods. A soft treatment using Freeze-EDTA-DNAse allows proper decellularization of xenografted tumor samples. Interestingly, proteomic data show that samples decellularized from TNBC basal-like subtype xenograft models had different extracellular matrix (ECM) compositions compared to the rest of the xenograft tumors tested. The in vitro recellularization of decellularized ECM (dECM) yields tumor-type–specific cell behavior in the TNBC context. Data show that dECM derived from xenograft tumors is a feasible substrate for reseeding purposes, thereby promoting tumor-type–specific cell behavior. These data serve as a proof-of-concept for further potential generation of patient-specific in vitro research models.Grant RTI2018-101708-A-I00 funded by MCIN/AEI/10.13039/501100011033 and by ERDF A way of making Europe. Grants RYC2018-025502-I and PRE2018-084542 are funded by MCIN/AEI/10.13039/501100011033 and by ESF Investing in your future. Grant MDM-2017-0720 Maria de Maeztu Units of Excellence Program funded by the Spanish State Research Agency. Grant KK-2019/00093 Elkartek program funded by Basque Government. Grant CICBMG_PhD_03_2021 funded by CICbiomaGUNE and Polymat. Grant CICBMG_PhD_05_2019 funded by CICbiomaGUNE and Polymat. 2019 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation, grant number IN[19]_CMA_BIO_0119. The BBVA Foundation accepts no responsibility for the opinions, statements, and contents included, which are entirely the responsibility of the authors

In vitro and in vivo efficacy, toxicity, bio-distribution and resistance selection of a novel antibacterial drug candidate

A synthetic antimicrobial peptide was identified as a possible candidate for the development of a new antibacterial drug. The peptide, SET-M33L, showed a MIC90 below 1.5 μM and 3 μM for Pseudomonas aeruginosa and Klebsiella pneumoniae, respectively. In in vivo models of P. aeruginosa infections, the peptide and its pegylated form (SET-M33L-PEG) enabled a survival percentage of 60-80% in sepsis and lung infections when injected twice i.v. at 5 mg/Kg, and completely healed skin infections when administered topically. Plasma clearance showed different kinetics for SET-M33L and SET-M33L-PEG, the latter having greater persistence two hours after injection. Bio-distribution in organs did not show significant differences in uptake of the two peptides. Unlike colistin, SET-M33L did not select resistant mutants in bacterial cultures and also proved non genotoxic and to have much lower in vivo toxicity than antimicrobial peptides already used in clinical practice. The characterizations reported here are part of a preclinical development plan that should bring the molecule to clinical trial in the next few years

Synthesis of radiolabelled aryl azides from diazonium salts: experimental and computational results permit the identification of the preferred mechanism

Experimental and computational studies on the formation of aryl azides from the corresponding diazonium salts support a stepwise mechanism via acyclic zwitterionic intermediates. The low energy barriers associated with both transition structures are compatible with very fast and efficient processes, thus making this method suitable for the chemical synthesis of radiolabelled aryl azides.Funding Agencies|RADIOMI project (EU FP7-PEOPLE-ITN-RADIOMI); Ministerio de Economia y Competitividad (MINECO) of Spain; FEDER [CTQ2013-45415-P]; University of the Basque Country (UPV/EHU) [UFI11/22 QOSYC]; Basque Government (GV/EJ) [IT-324-07]</p

In Vivo Tracking of the Degradation of Mesoporous Silica through 89Zr Radio-Labeled Core–Shell Nanoparticles

While mesoporous silica nanoparticles (MSNs) are extensively studied as high-potential drug delivery platforms, the successful clinical translation of these nanocarriers strongly depends on their biodistribution, biodegradation, and elimination patterns in vivo. Here, a novel method is reported to follow the in vivo degradation of MSNs by tracking a radioactive label embedded in the silica structure. Core–shell silica nanoparticles (NPs) with a dense core and a mesoporous shell are labeled with low quantities of the positron emitter 89Zr, either in the dense core or in the mesoporous shell. In vivo positron emission tomography imaging and ex vivo organ measurements reveal a remarkable difference in the 89Zr biodistribution between the shell-labeled and the core-labeled NPs. Release of the radiotracer from shell-labeled NPs is used as a probe of the extent of silica dissolution, and a prompt release of the radioisotope is observed, with partial excretion already in the first 2 h post injection, and a slower accumulation in bones over time. On the other hand, when 89Zr is embedded in the nanoparticle core, the biodistribution remains largely unchanged during the first 6 h. These findings indicate that MSNs have fast, hour-scale, degradation kinetics in vivo.Fil: Bindini, Elisa. No especifíca;Fil: Ramirez, Maria de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rios, Xabier. No especifíca;Fil: Cossío, Unai. No especifíca;Fil: Simó, Cristina. No especifíca;Fil: Gomez Vallejo, Vanessa. No especifíca;Fil: Soler Illia, Galo Juan de Avila Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Llop, Jordi. No especifíca;Fil: Moya, Sergio E.. No especifíca

Estudio comparativo de dos tipos de agujas en hemodiafiltración en línea de alta eficacia

La hemodiafi ltración on line post dilucional es la técnica más efi caz en la depuración de moléculas de diferentes pesos. El volumen convectivo y la dosis de diálisis pueden estar relacionado con la supervivencia del paciente. Ambos, parámetros están infl uenciados por el fl ujo sanguíneo, habiendo sido debatido el uso de diferentes calibres de aguja en lo referente a resultados deeficiencia y valoración de dolor. Objetivo: Comparar la efi cacia, seguridad, comodidad y sensación de dolor entre el catéter fístula y las agujas convencionales en el paciente en hemodiafi ltración en línea de alta eficacia. Estudio prospectivo cruzado sobre población prevalente en hemodiafiltración en línea posdilucional. Se analizan variables demográficas, hemodinámicas del acceso vascular, de seguridad y escala de dolor y comodidad pre-post para el enfermero en 1584 sesiones. Analisis estadistico SPSS 13.0. Signifi cación p< 0,05. No diferencias en Presion arterial, Presion venosa y recirculación. Sí en fl ujo sanguineo, siendo superior con las supercath. En efi cacia, diferencias signifi cativas en Kt (p=0,04), VTR (p=0,00) y litros de sangre dializada (p=0,01), supercath (63,1), (27,4), (113,1) versus convencional (60,9), (25,3), (108,5) respectivamente. Valoración enfermera de comodidad signifi cativamente (p=0,00) mejor con las agujas convencionales tanto en conexión como desconexión. Percepción de dolor para el paciente es mayor con supercath

In Vivo PET Imaging of the α4β2 Nicotinic Acetylcholine Receptor As a Marker for Brain Inflammation after Cerebral Ischemia

PET imaging of nicotinic acetylcholine receptors (nAChRs) could become an effective tool for the diagnosis and therapy evaluation of neurologic diseases. Despite this, the role of nAChRs 4 2 receptors after brain diseases such as cerebral ischemia and its involvement in inflammatory reaction is still largely unknown. To investigate this, we performed in parallel in vivo magnetic resonance imaging (MRI) and positron emission tomography (PET) with 2[ 18F]-fluoro-A85380 and [ 11C]PK11195 at 1, 3, 7, 14, 21, and 28 d after middle cerebral artery occlusion (MCAO) in rats. In the ischemic territory, PET with 2[ 18F]-fluoro-A85380 and [ 11C]PK11195 showed a progressive binding increase from days 3–7, followed by a progressive decrease from days 14 –28 after cerebral ischemia onset. Ex vivo immunohistochemistry for the nicotinic 4 2 receptor and the mitochondrial translocator protein (18 kDa) (TSPO) confirmed the PET findings and demonstrated the overexpression of 4 2 receptors in both microglia/macrophages and astrocytes from days 7–28 after experimentalischemic stroke. Likewise, the role played by 4 2 receptors on neuroinflammation was supported by the increase of [ 11C]PK11195 binding in ischemic rats treated with the 4 2 antagonist dihydro- -erythroidine hydrobromide (DHBE) at day 7 after MCAO. Finally, both functional and behavioral testing showed major impaired outcome at day 1 after ischemia onset, followed by a recovery of the sensorimotor function and dexterity from days 21–28 after experimental stroke. Together, these results suggest that the nicotinic 4 2receptor could have a key role in the inflammatory reaction underlying cerebral ischemia in rats

In vivo imaging of Α7 nicotinic receptors as a novel method to monitor neuroinflammation after cerebral ischemia.

In vivo positron emission tomography (PET) imaging of nicotinic acetylcholine receptors (nAChRs) is a promising tool for the imaging evaluation of neurologic and neurodegenerative diseases. However, the role of [alpha]7 nAChRs after brain diseases such as cerebral ischemia and its involvement in inflammatory reaction is still largely unknown. In vivo and ex vivo evaluation of [alpha]7 nAChRs expression after transient middle cerebral artery occlusion (MCAO) was carried out using PET imaging with [11C]NS14492 and immunohistochemistry (IHC). Pharmacological activation of [alpha]7 receptors was evaluated with magnetic resonance imaging (MRI), [18F]DPA-714 PET, IHC, real time polymerase chain reaction (qPCR) and neurofunctional studies. In the ischemic territory, [11C]NS14492 signal and IHC showed an expression increase of [alpha]7 receptors in microglia and astrocytes after cerebral ischemia. The role played by [alpha]7 receptors on neuroinflammation was supported by the decrease of [18F]DPA-714 binding in ischemic rats treated with the [alpha]7 agonist PHA 568487 at day 7 after MCAO. Moreover, compared with non-treated MCAO rats, PHA-treated ischemic rats showed a significant reduction of the cerebral infarct volumes and an improvement of the neurologic outcome. PHA treatment significantly reduced the expression of leukocyte infiltration molecules in MCAO rats and in endothelial cells after in vitro ischemia. Despite that, the activation of [alpha]7 nAChR had no influence to the blood brain barrier (BBB) permeability measured by MRI. Taken together, these results suggest that the nicotinic [alpha]7 nAChRs play a key role in the inflammatory reaction and the leukocyte recruitment following cerebral ischemia in rats