Characterization of single-walled carbon nanotube mats and their performance as electromechanical actuators

Carbon nanotube mats (buckypapers) were prepared from three commercial grades of single-walled carbon nanotubes (SWCNTs) and by two processing variants (i.e. filtration of centrifuged and uncentrifuged dispersions). Material properties such as Young’s modulus, tensile strength, electrical conductivity, electrical capacitance, specific surface area and morphology were investigated and put in relation to the in-plane actuation performance in an aqueous electrolyte (1 M NaCl). A dynamic mechanical analyzer was adapted for actuation strain measurements on the samples under various tensile prestress levels. High SWCNT purity and dispersibility were found to be crucial for preparing dense and strong cohesive mats with good actuation performance.     

MicroRNA-16 Restores Sensitivity to Tyrosine Kinase Inhibitors and Outperforms MEK Inhibitors in KRAS-Mutated Non-Small Cell Lung Cancer

Background: Non-small cell lung cancer (NSCLC) is the leading cause of cancer death worldwide. Chemotherapy, the treatment of choice in non-operable cases, achieves a dismal success rate, raising the need for new therapeutic options. In about 25% of NSCLC, the activating mutations of the KRAS oncogene define a subclass that cannot benefit from tyrosine kinase inhibitors (TKIs). The tumor suppressor miR-16 is downregulated in many human cancers, including NSCLC. The main objectives of this study were to evaluate miR-16 treatment to restore the TKI sensitivity and compare its efficacy to MEK inhibitors in KRAS-mutated NSCLC. Methods: We performed in vitro and in vivo studies to investigate whether miR-16 could be exploited to overcome TKI resistance in KRAS-mutated NSCLC. We had three goals: first, to identify the KRAS downstream effectors targeted by mir-16, second, to study the effects of miR-16 restoration on TKI resistance in KRAS-mutated NSCLC both in vitro and in vivo, and finally, to compare miR-16 and the MEK inhibitor selumetinib in reducing KRAS-mutated NSCLC growth in vitro and in vivo. Results: We demonstrated that miR-16 directly targets the three KRAS downstream effectors MAPK3, MAP2K1, and CRAF in NSCLC, restoring the sensitivity to erlotinib in KRAS-mutated NSCLC both in vitro and in vivo. We also provided evidence that the miR-16–erlotinib regimen is more effective than the selumetinib–erlotinib combination in KRAS-mutated NSCLC. Conclusions: Our findings support the biological preclinical rationale for using miR-16 in combination with erlotinib in the treatment of NSCLC with KRAS-activating mutations.     

Detection of Germline Variants in 450 Breast/Ovarian Cancer Families with a Multi-Gene Panel Including Coding and Regulatory Regions

With the progress of sequencing technologies, an ever-increasing number of variants of unknown functional and clinical significance (VUS) have been identified in both coding and non-coding regions of the main Breast Cancer (BC) predisposition genes. The aim of this study is to identify a mutational profile of coding and intron-exon junction regions of 12 moderate penetrance genes (ATM, BRIP1, CDH1, CHEK2, NBN, PALB2, PTEN, RAD50, RAD51C, RAD51D, STK11, TP53) in a cohort of 450 Italian patients with Hereditary Breast/Ovarian Cancer Syndrome, wild type for germline mutation in BRCA1/2 genes. The analysis was extended to 5′UTR and 3′UTR of all the genes listed above and to the BRCA1 and BRCA2 known regulatory regions in a subset of 120 patients. The screening was performed through NGS target resequencing on the Illumina platform MiSeq. 8.7% of the patients analyzed is carriers of class 5/4 coding variants in the ATM (3.6%), BRIP1 (1.6%), CHEK2 (1.8%), PALB2 (0.7%), RAD51C (0.4%), RAD51D (0.4%), and TP53 (0.2%) genes, while variants of uncertain pathological significance (VUSs)/class 3 were identified in 9.1% of the samples. In intron-exon junctions and in regulatory regions, variants were detected respectively in 5.1% and in 32.5% of the cases analyzed. The average age of disease onset of 44.4 in non-coding variant carriers is absolutely similar to the average age of disease onset in coding variant carriers for each proband’s group with the same cancer type. Furthermore, there is not a statistically significant difference in the proportion of cases with a tumor onset under age of 40 between the two groups, but the presence of multiple non-coding variants in the same patient may affect the aggressiveness of the tumor and it is worth underlining that 25% of patients with an aggressive tumor are carriers of a PTEN 3′UTR-variant. This data provides initial information on how important it might be to extend mutational screening to the regulatory regions in clinical practice.     

A High Throughput Approach Based on Dynamic High Pressure for the Encapsulation of Active Compounds in Exosomes for Precision Medicine

In recent decades, endogenous nanocarrier-exosomes have received considerable scientific interest as drug delivery systems. The unique proteo-lipid architecture allows the crossing of various natural barriers and protects exosomes cargo from degradation in the bloodstream. However, the presence of this bilayer membrane as well as their endogenous content make loading of exogenous molecules challenging. In the present work, we will investigate how to promote the manipulation of vesicles curvature by a high-pressure microfluidic system as a ground-breaking method for exosomes encapsulation. Exosomes isolated from Uppsala 87 Malignant Glioma (U87-MG) cell culture media were characterized before and after the treatment with high-pressure homogenization. Once their structural and biological stability were validated, we applied this novel method for the encapsulation in the lipidic exosomal bilayer of the chemotherapeutic Irinotecan HCl Trihydrate-CPT 11. Finally, we performed in vitro preliminary test to validate the nanobiointeraction of exosomes, uptake mechanisms, and cytotoxic effect in cell culture model.     

Critical Review of the Evolution of Extracellular Vesicles’ Knowledge: From 1946 to Today

Extracellular vesicles (EVs) are a family of particles/vesicles present in blood and body fluids, composed of phospholipid bilayers that carry a variety of molecules that can mediate cell communication, modulating crucial cell processes such as homeostasis, induction/dampening of inflammation, and promotion of repair. Their existence, initially suspected in 1946 and confirmed in 1967, spurred a sharp increase in the number of scientific publications. Paradoxically, the increasing interest for EV content and function progressively reduced the relevance for a precise nomenclature in classifying EVs, therefore leading to a confusing scientific production. The aim of this review was to analyze the evolution of the progress in the knowledge and definition of EVs over the years, with an overview of the methodologies used for the identification of the vesicles, their cell of origin, and the detection of their cargo. The MISEV 2018 guidelines for the proper recognition nomenclature and ways to study EVs are summarized. The review finishes with a “more questions than answers” chapter, in which some of the problems we still face to fully understand the EV function and potential as a diagnostic and therapeutic tool are analyzed.     

Structural Investigation and Molecular Modeling Studies of Strobilurin-Based Fungicides Active against the Rice Blast Pathogen Pyricularia oryzae

The increasing emergence of fungicide-resistant pathogens requires urgent solutions for crop disease management. Here, we describe a structural investigation of new fungicides obtained by combining strobilurin and succinate dehydrogenase inhibitor pharmacophores. We identified compounds endowed with very good activity against wild-type Pyricularia oryzae, combined in some cases with promising activity against strobilurin-resistant strains. The first three-dimensional model of P. oryzae cytochrome bc1 complex containing azoxystrobin as a ligand was developed. The model was validated with a set of commercially available strobilurins, and it well explains both the resistance mechanism to strobilurins mediated by the mutation G143A and the activity of metyltetraprole against strobilurin-resistant strains. The obtained results shed light on the key recognition determinants of strobilurin-like derivatives in the cytochrome bc1 active site and will guide the further rational design of new fungicides able to overcome resistance caused by G143A mutation in the rice blast pathogen.     

Evaluation of direct light processing for the fabrication of bioactive ceramic scaffolds: Effect of pore/strut size on manufacturability and mechanical performance

Bioactive ceramic scaffolds for bone regeneration consisting of a three-dimensional mesh of interpenetrating struts with square section were fabricated via Digital Light Processing (DLP). The ability of the technique to manufacture 3D porous structures from β-tricalcium phosphate (β-TCP) powders with different dimensions of struts and pores was evaluated, identifying the possibilities and limitations of the manufacturing process. Small pore sizes were found to seriously complicate the elimination of excess slurry from the scaffold’s innermost pores. The effect of the strut/pore size on the mechanical performance of the scaffolds under compressive stresses was also evaluated, but no significant influence was found. Under compressive stresses, the structures resulted weaker when tested perpendicularly to the printing plane due to interlayer shear failure. Interlayer superficial grooves are proposed as potential failure-controlling defects, which could also explain the lack of a Weibull size effect on the mechanical strength of the fabricated DLP scaffolds.