Blood-brain barrier biomarkers.

The blood-brain barrier (BBB) is a dynamic interface that regulates the exchange of molecules and cells between the brain parenchyma and the peripheral blood. The BBB is mainly composed of endothelial cells, astrocytes and pericytes. The integrity of this structure is essential for maintaining brain and spinal cord homeostasis and protection from injury or disease. However, in various neurological disorders, such as traumatic brain injury, Alzheimer's disease, and multiple sclerosis, the BBB can become compromised thus allowing passage of molecules and cells in and out of the central nervous system parenchyma. These agents, however, can serve as biomarkers of BBB permeability and neuronal damage, and provide valuable information for diagnosis, prognosis and treatment. Herein, we provide an overview of the BBB and changes due to aging, and summarize current knowledge on biomarkers of BBB disruption and neurodegeneration, including permeability, cellular, molecular and imaging biomarkers. We also discuss the challenges and opportunities for developing a biomarker toolkit that can reliably assess the BBB in physiologic and pathophysiologic states.

Specific nanoprobe design for MRI: Targeting laminin in the blood-brain barrier to follow alteration due to neuroinflammation.

Chronic neuroinflammation is characterized by increased blood-brain barrier (BBB) permeability, leading to molecular changes in the central nervous system that can be explored with biomarkers of active neuroinflammatory processes. Magnetic resonance imaging (MRI) has contributed to detecting lesions and permeability of the BBB. Ultra-small superparamagnetic particles of iron oxide (USPIO) are used as contrast agents to improve MRI observations. Therefore, we validate the interaction of peptide-88 with laminin, vectorized on USPIO, to explore BBB molecular alterations occurring during neuroinflammation as a potential tool for use in MRI. The specific labeling of NPS-P88 was verified in endothelial cells (hCMEC/D3) and astrocytes (T98G) under inflammation induced by interleukin 1ß (IL-1ß) for 3 and 24 hours. IL-1ß for 3 hours in hCMEC/D3 cells increased their co-localization with NPS-P88, compared with controls. At 24 hours, no significant differences were observed between groups. In T98G cells, NPS-P88 showed similar nonspecific labeling among treatments. These results indicate that NPS-P88 has a higher affinity towards brain endothelial cells than astrocytes under inflammation. This affinity decreases over time with reduced laminin expression. In vivo results suggest that following a 30-minute post-injection, there is an increased presence of NPS-P88 in the blood and brain, diminishing over time. Lastly, EAE animals displayed a significant accumulation of NPS-P88 in MRI, primarily in the cortex, attributed to inflammation and disruption of the BBB. Altogether, these results revealed NPS-P88 as a biomarker to evaluate changes in the BBB due to neuroinflammation by MRI in biological models targeting laminin.

Native Entomopathogenic Fungi Isolated from Rhynchophorus palmarum (Linnaeus, 1758) in Northeast Brazil.

Both palm weevils, the South American (Rhynchophorus palmarum) (SAPW) and the red palm weevil (R. ferrugineus, RPW), are present in South America, affecting commercial, ornamental, and native palms. These pests oviposit and thrive on selected Arecaceae. R. palmarum mainly infests coconut (Cocos nucifera), oil palms (Elaeis guineensis), and other ornamental and native palms in America, causing a significant social impact on growers. The weevils fulfill a significant ectosymbiotic macro- and microorganism role in the first period of larval development, worsening the damage which, during this period, is not yet apparent. Palm protection in the Brazilian context suggests the use of indigenous agents for microbiological biocontrol. This research identifies three Brazilian Beauveria bassiana isolates: CVAD01, CVAD02, and CVAD06. The results suggest that the strain's impact on R. palmarum can also be compared with that of the commercial strain Beauveria bassiana. Phylogenetic analysis allowed the delimitation of species of Beauveria (Hypocreales). Pathogenicity tests caused significant mortality in R. palmarum. The isolates CVAD01, CVAD02, and CVADO6 showed high pathogenicity between 7 and 21 days, with mortality rates between 90 and 100%, suggesting that they may be effective biological control agents of R. palmarum in the field when used, within available means, to mitigate the impact of R. palmarum and R. ferrugineus in South America.

Caveolin-1-dependent tenascin C inclusion in extracellular vesicles is required to promote breast cancer cell malignancy.

Background: Elevated expression of CAV1 in breast cancer increases tumor progression. Extracellular vesicles (EVs) from CAV1-expressing MDA-MB-231 breast cancer cells contain Tenascin C (TNC), but the relevance of TNC remained to be defined. Methods: EVs were characterized by nanotracking analysis, microscopy and western blotting. The uptake of EVs by cells was studied using flow cytometry. The effects of EVs on breast cancer cells were tested in migration, invasion, colony formation and in vivo assays. Results: EVs were taken up by cells; however, only those containing TNC promoted invasiveness. In vivo, EVs lacking TNC ceased to promote tumor growth. Conclusion: CAV1 and TNC contained in breast cancer cell-derived EVs were identified as proteins that favor progression of breast cancer.

Caveolin-1 (CAV1) is a protein that in breast cancer increases with disease progression. Extracellular vesicles (EVs) from breast cancer cells with CAV1 also contain Tenascin C (TNC) protein, but the importance of TNC remained to be defined. EVs were identified by size, microscopy and protein analysis. The effects of EVs on breast cancer cells were studied using cells and experiments in animals. CAV1 expression promotes TNC inclusion into EVs, which increased the aggressiveness of recipient breast cancer cells. In animals, only EVs with TNC increased features associated with cancer spread, while EVs lacking TNC reduced tumor growth.

An advanced biphasic porous and injectable scaffold displays a fine balance between mechanical strength and remodeling capabilities essential for cartilage regeneration.

An important challenge in tissue engineering is the regeneration of functional articular cartilage (AC). In the field, biomimetic hydrogels are being extensively studied as scaffolds that recapitulate microenvironmental features or as mechanical supports for transplanted cells. New advanced hydrogel formulations based on salmon methacrylate gelatin (sGelMA), a cold-adapted biomaterial, are presented in this work. The psychrophilic nature of this biomaterial provides rheological advantages allowing the fabrication of scaffolds with high concentrations of the biopolymer and high mechanical strength, suitable for formulating injectable hydrogels with high mechanical strength for cartilage regeneration. However, highly intricate cell-laden scaffolds derived from highly concentrated sGelMA solutions could be deleterious for cells and scaffold remodeling. On this account, the current study proposes the use of sGelMA supplemented with a mesophilic sacrificial porogenic component. The cytocompatibility of different sGelMA-based formulations is tested through the encapsulation of osteoarthritic chondrocytes (OACs) and stimulated to synthesize extracellular matrix (ECM) components in vitro and in vivo. The sGelMA-derived scaffolds reach high levels of stiffness, and the inclusion of porogens impacts positively the scaffold degradability and molecular diffusion, improved fitness of OACs, increased the expression of cartilage-related genes, increased glycosaminoglycan (GAG) synthesis, and improved remodeling toward cartilage-like tissues. Altogether, these data support the use of sGelMA solutions in combination with mammalian solid gelatin beads for highly injectable formulations for cartilage regeneration, strengthening the importance of the balance between mechanical properties and remodeling capabilities.

Ocular Manifestations of Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic disease connected to the immune system, with a predilection for the gastrointestinal tract. However, a large proportion of the patients have extraintestinal manifestations (EIM), and the ocular system is affected in some patients. The clinical presentation of ocular pathology is broad, ranging from asymptomatic cases to blindness, leading to high morbidity. Ocular complications can be primary and, in general, are associated with episodes of acute flare-ups that subside with immunological management of the digestive disease. Secondary complications arise from the primary ones and as adverse effects of immunological treatment. In addition, on many occasions, the ocular manifestation may appear prior to the presentation of digestive symptoms. The presence of a multidisciplinary team that includes a gastroenterologist and an ophthalmologist is important in order to achieve early diagnosis of ocular complications, thereby preventing, treating, and avoiding unfavorable and irreversible long-term ocular sequelae.

A novel porous hydrogel based on hybrid gelation for injectable and tough scaffold implantation and tissue engineering applications.

Although there have been many advances in injectable hydrogels as scaffolds for tissue engineering or as payload-containing vehicles, the lack of adequate microporosity for the desired cell behavior, tissue integration, and successful tissue generation remains an important drawback. Herein, we describe an effective porous injectable system that allowsin vivoformation of pores through conventional syringe injection at room temperature. This system is based on the differential melting profiles of photocrosslinkable salmon gelatin and physically crosslinked porogens of porcine gelatin (PG), in which PG porogens are solid beads, while salmon methacrylamide gelatin remains liquid during the injection procedure. After injection and photocrosslinking, the porogens were degraded in response to the physiological temperature, enabling the generation of a homogeneous porous structure within the hydrogel. The resultant porogen-containing formulations exhibited controlled gelation kinetics within a broad temperature window (18.5 ± 0.5-28.8 ± 0.8 °C), low viscosity (133 ± 1.4-188 ± 16 cP), low force requirements for injectability (17 ± 0.3-39 ± 1 N), robust mechanical properties after photo-crosslinking (100.9 ± 3.4-332 ± 13.2 kPa), and favorable cytocompatibility (>70% cell viability). Remarkably,in vivosubcutaneous injection demonstrated the suitability of the system with appropriate viscosity and swift crosslinking to generate porous hydrogels. The resulting injected porous constructs showed favorable biocompatibility and facilitated cell infiltration for desirable potential tissue remodeling. Finally, the porogen-containing formulations exhibited favorable handling, easy deposition, and good shape fidelity when used as bioinks in 3D bioprinting technology. This injectable porous system serves as a platform for various biomedical applications, thereby inspiring future advances in cell therapy and tissue engineering.

Understanding the Molecular Conformation and Viscoelasticity of Low Sol-Gel Transition Temperature Gelatin Methacryloyl Suspensions.

For biomedical applications, gelatin is usually modified with methacryloyl groups to obtain gelatin methacryloyl (GelMA), which can be crosslinked by a radical reaction induced by low wavelength light to form mechanically stable hydrogels. The potential of GelMA hydrogels for tissue engineering has been well established, however, one of the main disadvantages of mammalian-origin gelatins is that their sol-gel transitions are close to room temperature, resulting in significant variations in viscosity that can be a problem for biofabrication applications. For these applications, cold-water fish-derived gelatins, such as salmon gelatin, are a good alternative due to their lower viscosity, viscoelastic and mechanical properties, as well as lower sol-gel transition temperatures, when compared with mammalian gelatins. However, information regarding GelMA (with special focus on salmon GelMA as a model for cold-water species) molecular conformation and the effect of pH prior to crosslinking, which is key for fabrication purposes since it will determine final hydrogel's structure, remains scarce. The aim of this work is to characterize salmon gelatin (SGel) and salmon methacryloyl gelatin (SGelMA) molecular configuration at two different acidic pHs (3.6 and 4.8) and to compare them to commercial porcine gelatin (PGel) and methacryloyl porcine gelatin (PGelMA), usually used for biomedical applications. Specifically, we evaluated gelatin and GelMA samples' molecular weight, isoelectric point (IEP), their molecular configuration by circular dichroism (CD), and determined their rheological and thermophysical properties. Results showed that functionalization affected gelatin molecular weight and IEP. Additionally, functionalization and pH affected gelatin molecular structure and rheological and thermal properties. Interestingly, the SGel and SGelMA molecular structure was more sensitive to pH changes, showing differences in gelation temperatures and triple helix formation than PGelMA. This work suggests that SGelMA presents high tunability as a biomaterial for biofabrication, highlighting the importance of a proper GelMA molecular configuration characterization prior to hydrogel fabrication.

Three double-dose reinforced hepatitis B revaccination scheme for patients with cirrhosis unresponsive to the standard regimen: an open-label randomised clinical trial.

OBJECTIVE: We aimed to compare the response rates between two different hepatitis B virus vaccination schedules for cirrhotic subjects who were non-responders to the first three 40 µg doses (month 0-1-2), and identify factors associated with the final response. DESIGN: A total of 120 cirrhotic patients (72.5% decompensated) were randomised at a 1:1 ratio to receive a single 40 µg booster vaccination at month 6 (classical arm) versus an additional round of three new 40 µg doses administered at monthly intervals (experimental arm). The main outcome was the rate of postvaccinal anti-hepatitis B surface antibodies levels ≥10 mIU/mL. RESULTS: Efficacy by ITT analysis was higher in the experimental arm (46.7%) than in the classical one (25%); OR 2.63, p=0.013. The experimental arm increased response rates compared with the classical one from 31% to 68% (OR 4.72; p=0.007), from 24.4% to 50% (OR 3.09; p=0.012) and from 24.4% to 53.8% (OR 3.62; p=0.007), in Child A, Model for End-Stage Liver Disease (MELD) <15 and MELD-Na<15 patients, respectively. Patients with more advanced liver disease did not benefit from the reinforced scheme. Both regimens showed similar safety profiles. Multivariable analysis showed that the experimental treatment was independently response associated when adjusted across three logistic regression models indicating equivalent cirrhosis severity. CONCLUSION: For cirrhotic patients, the revaccination of non-responders to the first three dose cycle, with three additional 40 µg doses, achieved significantly better response rates to those obtained with an isolated 40 µg booster dose. TRIAL REGISTRATION NUMBER: NCT01884415.

KRAS Gene Mutation in Patients Undergoing Liver Resections for Colorectal Cancer. Is There an Advantage to Anatomical Resections?

Introduction: Several factors have been described to make a prognostic assessment of patients with liver metastases due to colorectal cancer and to define the benefit of the surgical management of metastatic involvement; one of these factors is the status of the KRAS gene since its mutation is associated with worse outcomes. This study aims to describe the outcomes for a retrospective series of patients after liver resections for metastatic colorectal cancer concerning KRAS gene status. Materials and methods: The study involves a retrospective cohort of patients undergoing liver metastasectomy for colorectal cancer with KRAS mutation study from 2009-2013 at the National Institute of Cancerology in Colombia. Five-year survival analyses (overall and disease-free) were performed according to KRAS mutation status and the type of liver resection performed using the Kaplan-Meier estimate. Results: 35 patients undergoing liver metastasectomy were analyzed, of which 42.8% had KRAS gene mutation. Median overall survival was 34.2 months for patients with KRAS- mutant and 46.5 for non-mutant. The median survival for KRAS-mutant patients with anatomic resections was 43.5 months versus 23.5 months for nonanatomic resections. Conclusions: Performing anatomic resections during liver metastasectomy in patients with KRAS mutants could be associated with an improvement in overall survival. It is necessary to continue building the evidence for adequate decision-making in patients with KRAS mutants who will undergo liver resections.

Introducción: se han descrito varios factores para realizar una evaluación pronóstica de los pacientes con metástasis hepáticas por cáncer colorrectal y definir el beneficio en el manejo quirúrgico del compromiso metastásico; uno de estos factores es el estado del gen KRAS, debido a que su mutación está relacionada con peores desenlaces. El objetivo de este estudio es describir los desenlaces para una serie retrospectiva de pacientes después de resecciones hepáticas por metástasis de cáncer colorrectal en relación con el estado del gen KRAS. Metodología: cohorte retrospectiva de pacientes llevados a metastasectomía hepática por cáncer colorrectal con estudio de mutación KRAS durante el período 2009-2013, en el Instituto Nacional de Cancerología en Colombia. Se realizaron análisis de supervivencia a 5 años (global y libre de enfermedad) según el estado de mutación KRAS y según el tipo de resección hepática realizada mediante el método de Kaplan-Meier. Resultados: se analizaron a 35 pacientes llevados a metastasectomía hepática, de los cuales el 42,8% presentaba mutación del gen KRAS. La supervivencia global media fue de 34,2 meses para los pacientes con KRAS mutado y de 46,5 para los no mutados. La supervivencia media para los pacientes con KRAS mutado con resecciones anatómicas fue de 43,5 meses frente a 23,5 meses en los que se realizaron resecciones no anatómicas. Conclusiones: realizar resecciones anatómicas durante la metastasectomía hepática en los pacientes con KRAS mutado podría estar asociado con una mejoría en la supervivencia global. Se requiere continuar en la construcción de la evidencia que permita una adecuada toma de decisiones de los pacientes con KRAS mutado que serán llevados a resecciones hepáticas.