Surface specific peptide immobilization on radiografted polymers as potential screening assays for antiangiogenic immunotherapy

International audienceAngiogenesis is a key process of cancer development and metastasis. It's inhibition is an important and promising strategy to block tumor growth and invasion. One of these approaches, based on antiangiogenic immunotherapy, is the recognition of a specific region of an angiogenic growth factor, called VEGF-A, by monoclonal antibodies. Thus, we aimed to design a novel assay to screen potential monoclonal antibodies directed against VEGF-A. In a first approach, we chose to perform covalent coupling of angiogenesis active cyclopeptides onto biocompatible thermoplastic transparent PVDF films and to fully characterize the chemical structure, the surface state and the biochemical properties of the synthesized devices. Electron beam radiation created radical sites on PVDF films without adding any toxic chemicals. These primary radicals and some induced peroxides were used as initiators for acrylic acid polymerization. Under our experimental conditions, surface grafting was favoured. Functionalization of PVDF-g-PAA films with peptides via a spacer arm was possible by performing two subsequent coupling reactions. EDC was used as coupling agent. Spacer arm saturation of the film surface was achieved for 25 mol% yield meaning that one spacer arm on four carboxylic acids were covalently bound. Peptide immobilization resulted in binding 10 times less leading to a final 3 mol% yield. Binding densities are governed by their individual space requirements. Each chemical step has been followed by FTIR in ATR mode, NMR using HR MAS technique and XPS. From XPS results, a layer of peptide covered PVDF-g-PAA film surface. The amounts of covalently immobilized peptide were determined using indirect UV spectroscopy on supernatant reaction solution. Yields were correlated with high resolution NMR results. The peptide/antibody recognition validated our system showing the conservation of peptide tridimensional structure with a positive response to specific antibodies. Because of the covalent protein linkage to PVDF films, a simple cleaning with immunoaffinity chromatography buffer allows the films to be reused

Current approaches and future perspectives on strategies for the development of personalized tissue engineering therapies

Personalized tissue engineering and regenerative medicine (TERM) therapies propose patient-oriented effective solutions, considering individual needs. Cell-based therapies, for example, may benefit from cell sources that enable easier autologous set-ups or from recent developments on IPS cells technologies towards effective personalized therapeutics. Furthermore, the customization of scaffold materials to perfectly fit a patientâ s tissue defect through rapid prototyping technologies, also known as 3D printing, is now a reality. Nevertheless, the timing to expand cells or to obtain functional in vitrotissue substitutes prior to implantation prevents advancements towards routine use upon patient´s needs. Thus, personalized therapies also anticipate the importance of creating off-the-shelf solutions to enable immediately available tissue engineered products. This paper reviews the main recent developments and future challenges to enable personalized TERM approaches and to bring these technologies closer to clinical applications.The authors wish to acknowledge the financial support of the Portuguese Foundation for Science and Technology for the post-doctoral grant (SFRH/BPD/111729/2015) and Recognize (UTAP-ICDT/CTM-BIO/0023/2014), and the project RL3 -TECT -NORTE-07-0124-FEDER-000020 co-financed by ON.2 (NSRF), through ERDF

High frequency of CHD7 mutations in congenital hypogonadotropic hypogonadism

Congenital hypogonadotropic hypogonadism (CHH) is characterized by lack of normal pubertal development due to deficient gonadotropin-releasing hormone (GnRH) secretion or action, and is caused by genetic defects in several genes. Mutations in the CHD7 gene cause CHARGE syndrome (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth and development, Genital hypoplasia and Ear abnormalities), but have also been found in patients with isolated CHH. The aim of this study was to identify CHD7 mutations in patients with CHH. Fifty Portuguese patients with CHH were screened for mutations in the CHD7 gene by DNA sequencing. Eight (16%) patients had CHD7 rare sequence variants that consisted of six missense (p.Gly388Glu, p.His903Pro, p.Thr1082Ile, p.Val1452Leu, p.Asp1854Gly, and p.Arg2065His) and two synonymous (p.Ser559Ser, and p.Ala2785Ala) mutations. Five of these mutations have never been reported before. Three CHD7 mutations occurred in patients that had mutations in additional CHH-genes. This study uncovered novel genetic variants that expand the known spectrum of mutations associated with CHH. The frequency of CHD7 mutations in this cohort was higher than that of other major CHH-genes and confirms the importance of including CHD7 in the genetic testing of CHH, even in the absence of additional CHARGE features.info:eu-repo/semantics/publishedVersio

HumMeth27QCReport: an R package for quality control and primary analysis of Illumina Infinium methylation data

<p>Abstract</p> <p>Background</p> <p>The study of the human DNA methylome has gained particular interest in the last few years. Researchers can nowadays investigate the potential role of DNA methylation in common disorders by taking advantage of new high-throughput technologies. Among these, Illumina Infinium assays can interrogate the methylation levels of hundreds of thousands of CpG sites, offering an ideal solution for genome-wide methylation profiling. However, like for other high-throughput technologies, the main bottleneck remains at the stage of data analysis rather than data production.</p> <p>Findings</p> <p>We have developed <it>HumMeth27QCReport</it>, an R package devoted to researchers wanting to quickly analyse their Illumina Infinium methylation arrays. This package automates quality control steps by generating a report including sample-independent and sample-dependent quality plots, and performs primary analysis of raw methylation calls by computing data normalization, statistics, and sample similarities. This package is available at CRAN repository, and can be integrated in any Galaxy instance through the implementation of ad-hoc scripts accessible at Galaxy Tool Shed.</p> <p>Conclusions</p> <p>Our package provides users of the Illumina Infinium Methylation assays with a simplified, automated, open-source quality control and primary analysis of their methylation data. Moreover, to enhance its use by experimental researchers, the tool is being distributed along with the scripts necessary for its implementation in the Galaxy workbench. Finally, although it was originally developed for HumanMethylation27, we proved its compatibility with data generated with the HumanMethylation450 Bead Chip.</p

International Agency for Research on Cancer Workshop on 'Expression array analyses in breast cancer taxonomy'

In May 2006, a workshop on Expression array analyses in breast cancer taxonomy was held at the International Agency for Research on Cancer (IARC). The workshop covered an array of topics from the validity of the currently defined breast tumor subtypes and other expression profile-based signatures to the technical limitations of expression analysis and the types of platforms on which these omics results will eventually reach clinical practice. Overall, the workshop participants believed firmly that tumor taxonomy is likely to yield improved prognostic and predictive markers. Even so, further standardization and validation are required before clinical trials are set in motion

Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

Multiscale multifactorial approaches for engineering tendon substitutes

The physiology of tendons and the continuous strains experienced daily make tendons very prone to injury. Excessive and prolonged loading forces and aging also contribute to the onset and progression of tendon injuries, and conventional treatments have limited efficacy in restoring tendon biomechanics. Tissue engineering and regenerative medicine (TERM) approaches hold the promise to provide therapeutic solutions for injured or damaged tendons despite the challenging cues of tendon niche and the lack of tendon-specific factors to guide cellular responses and tackle regeneration. The roots of engineering tendon substitutes lay in multifactorial approaches from adequate stem cells sources and environmental stimuli to the construction of multiscale 3D scaffolding systems. To achieve such advanced tendon substitutes, incremental strategies have been pursued to more closely recreate the native tendon requirements providing structural as well as physical and chemical cues combined with biochemical and mechanical stimuli to instruct cell behavior in 3D architectures, pursuing mechanically competent constructs with adequate maturation before implantation.Authors acknowledge the project “Accelerating tissue engineering and personalized medicine discoveries by the integration of key enabling nanotechnologies, marinederived biomaterials and stem cells,” supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Authors acknowledge the H2020 Achilles Twinning Project No. 810850, and also the European Research Council CoG MagTendon No. 772817, and the FCT Project MagTT PTDC/CTM-CTM/ 29930/2017 (POCI-01-0145-FEDER-29930