Magnetic Polyion Complex Micelles for Cell Toxicity Induced by Radiofrequency Magnetic Field Hyperthermia.

Magnetic nanoparticles (MNPs) of magnetite (Fe₃O₄) were prepared using a polystyrene--poly(2-vinylpyridine) copolymer (denoted G0PS--P2VP or G1) as template. These MNPs were subjected to self-assembly with a poly(acrylic acid)--poly(2-hydroxyethyl acrylate) double-hydrophilic block copolymer (DHBC), PAA--PHEA, to form water-dispersible magnetic polyion complex (MPIC) micelles. Large Fe₃O₄ crystallites were visualized by transmission electron microscopy (TEM) and magnetic suspensions of MPIC micelles exhibited improved colloidal stability in aqueous environments over a wide pH and ionic strength range.

Atmospheric Plasma Deposition of Methacrylate Layers Containing Catechol/Quinone Groups: An Alternative to Polydopamine Bioconjugation for Biomedical Applications.

Bioconjugation of enzymes on coatings based on polydopamine (PDA) layers is an appealing approach to control biological responses on biomedical implant surfaces. As alternative to PDA wet deposition, a fast, solvent-free, and dynamic deposition approach based on atmospheric-pressure plasma dielectric barrier discharge process is considered to deposit on metallic surfaces acrylic-based interlayers containing highly chemically reactive catechol/quinone groups. A biomimetic approach based on covalent immobilization of Dispersin B, an enzyme with antibiofilm properties, shows the bioconjugation potential of the novel plasma polymer layers.

OLFM4, KNG1 and Sec24C identified by proteomics and immunohistochemistry as potential markers of early colorectal cancer stages.

Background: Despite recent advances in colorectal cancer (CRC) diagnosis and population screening programs, the identification of patients with preneoplastic lesions or with early CRC stages remains challenging and is important for reducing CRC incidence and increasing patient's survival.

Methods: We analysed 76 colorectal tissue samples originated from early CRC stages, normal or inflamed mucosa by -. The characterisation of three selected biomarker candidates was performed by immunohistochemistry on an independent set of precancerous and cancerous lesions harbouring increasing CRC stages.

Photoreversibility and Biocompatibility of Polydimethylsiloxane-Coumarin as Adjustable Intraocular Lens Material.

Polydimethylsiloxane (PDMS) constitutes an interesting material for a variety of biomedical applications, especially as intraocular lenses (IOLs), for its excellent transparency. In this work, a photoreversible PDMS-coumarin network, whose shape and properties can be adjusted postoperatively in a noninvasive manner, is developed. The synthesis of PDMS-coumarin is achieved by amidation of a coumarin acid chloride derivative with amine-functionalized PDMSs.

Biocompatibility of polymer-infiltrated-ceramic-network (PICN) materials with Human Gingival Keratinocytes (HGKs).

Objective: Biocompatibility of polymer-infiltrated-ceramic-network (PICN) materials, a new class of CAD-CAM composites, is poorly explored in the literature, in particular, no data are available regarding Human Gingival Keratinocytes (HGK). The first objective of this study was to evaluate the in vitro biocompatibility of PICNs with HGKs in comparison with other materials typically used for implant prostheses. The second objective was to correlate results with PICN monomer release and indirect cytotoxicity.

Biocompatible Polyion Complex Micelles Synthesized from Arborescent Polymers.

Water-dispersible polyion complex (PIC) micelles were prepared by the self-assembly of an arborescent polystyrene-graft-poly(2-vinylpyridine) copolymer (denoted G0PS-g-P2VP or G1) serving as core and a poly(acrylic acid)-block-poly(2-hydroxyethyl acrylate) (PAA-b-PHEA) double-hydrophilic block copolymer (DHBC) forming a shell. Varying the density of hydrophilic polymer chains in the stabilizing layer provided control over the size and structure of the entities obtained, from large flocculated species to stable isolated PIC micelles with diameters ranging from 42 to 67 nm. The hydrodynamic radius (determined from dynamic light scattering measurements), and the weight-average molar mass (M̅) and radius of gyration of the scatterers (extracted from static multiangle light scattering data) evidenced the formation of either isolated or aggregated PIC micelles depending on the self-assembly conditions used (pH, concentration and mixing molar ratio f).

Biocompatibility of polymer-infiltrated-ceramic-network (PICN) materials with Human Gingival Fibroblasts (HGFs).

Objectives: Polymer-infiltrated-ceramic-network (PICN) materials constitute an innovative class of CAD-CAM materials offering promising perspectives in prosthodontics, but no data are available in the literature regarding their biological properties. The objective of the present study was to evaluate the in vitro biocompatibility of PICNs with human gingival fibroblasts (HGFs) in comparison with materials typically used for implant prostheses and abutments.

Methods: HGF attachment, proliferation and spreading on discs made of PICN, grade V titanium (Ti), yttrium zirconia (Zi), lithium disilicate glass-ceramic (eM) and polytetrafluoroethylene (negative control), were evaluated using a specific insert-based culture system (IBS-R).

Absence of selenium protection against methylmercury toxicity in harbour seal leucocytes in vitro.

Previous studies described high concentrations of mercury (Hg) and selenium (Se) in the blood of harbour seals, Phoca vitulina from the North Sea. In the present study, we evaluated the in vitro potential protective effects of sodium selenite (Na2SeO3) and selenomethionine (SeMet) on cell proliferation of harbour seal lymphocytes exposed to MeHgCl 0.75μM.

A new method using insert-based systems (IBS) to improve cell behavior study on flexible and rigid biomaterials.

In vitro studies about biomaterials biological properties are essential screening tests. Yet cell cultures encounter difficulties related to cell retention on material surface or to the observation of both faces of permeable materials. The objective of the present study was to develop a reliable in vitro method to study cell behavior on rigid and flexible/permeable biomaterials elaborating two specific insert-based systems (IBS-R and IBS-F respectively).

Effects of Methylmercury on Harbour Seal Peripheral Blood Leucocytes In Vitro Studied by Electron Microscopy.

Methylmercury (MeHg) is highly immunotoxic and can alter the health status of the harbour seal, Phoca vitulina, from the North Sea. To investigate the mechanism of MeHg-induced toxicity in harbour seal lymphocytes, Concanavalin A (ConA)-stimulated peripheral blood leucocytes were exposed in vitro to sublethal concentrations of MeHgCl (0.2, 1, and 2 µM) for 72 h and then analysed for their viability and ultrastructure.

Crystallisation-driven self-assembly of poly(2-isopropyl-2-oxazoline)-block-poly(2-methyl-2-oxazoline) above the LCST.

The solution behaviour in water of a polyoxazoline-type block copolymer, namely poly(2-isopropyl-2-oxazoline)-block-poly(2-methyl-2-oxazoline), denoted as P(iPrOx-b-MeOx), above the lower critical solution temperature (LCST) of the PiPrOx block was exploited to induce a temporary or permanent self-assembly. Spherical micelles were first obtained and could be disassembled in a reversible manner when kept for a short period of time (i.e.

Gold nanorods coated with mesoporous silica shell as drug delivery system for remote near infrared light-activated release and potential phototherapy.

In this study, we report the synthesis of a nanoscaled drug delivery system, which is composed of a gold nanorod-like core and a mesoporous silica shell (GNR@MSNP) and partially uploaded with phase-changing molecules (1-tetradecanol, TD, T(m) 39 °C) as gatekeepers, as well as its ability to regulate the release of doxorubicin (DOX). Indeed, a nearly zero premature release is evidenced at physiological temperature (37 °C), whereas the DOX release is efficiently achieved at higher temperature not only upon external heating, but also via internal heating generated by the GNR core under near infrared irradiation. When tagged with folate moieties, GNR@MSNPs target specifically to KB cells, which are known to overexpress the folate receptors.

RGD surface functionalization of the hydrophilic acrylic intraocular lens material to control posterior capsular opacification.

Posterior Capsular Opacification (PCO) is the capsule fibrosis developed on implanted IntraOcular Lens (IOL) by the de-differentiation of Lens Epithelial Cells (LECs) undergoing Epithelial Mesenchymal Transition (EMT). Literature has shown that the incidence of PCO is multifactorial including the patient's age or disease, surgical technique, and IOL design and material. Reports comparing hydrophilic and hydrophobic acrylic IOLs have shown that the former has more severe PCO.

Poly(2-oxazoline)-based nanogels as biocompatible pseudopolypeptide nanoparticles.

Hydrophilic nanogels based on partially hydrolyzed poly(2-ethyl-2-oxazoline) were synthesized in dilute aqueous media in the presence of 1,6-hexanediol diglycidyl ether as a cross-linker. Nanogel formation was monitored by DLS and HSQC NMR spectroscopy, and the final nano-objects were characterized by DLS, TEM, AFM, and NanoSight analyses. Nanogels with a hydrodynamic radius of 78 nm exhibiting a slight positive surface charge were obtained.

Evaluation of a class of polyurethane materials for intraocular lens manufacturing.

Ophthalmic lenses are medical devices with considerable requirements in terms of optical, biomechanical and biological performance. There is limited number of materials used for their manufacturing, comprising mainly silicones and poly(meth)acrylates. This series of publications aims at investigating the applicability of thermoplastic polyurethane elastomers (TPU) for the manufacturing of ophthalmic lenses and examining the properties of the respective devices.

Comparison of two FFPE preparation methods using label-free shotgun proteomics: Application to tissues of diverticulitis patients.

Unlabelled: Formalin-fixed paraffin-embedded (FFPE) specimens of patients are useful sources of materials for clinical research and have recently gained interest for use in the discovery of clinical proteomic biomarkers. However, the critical step in this field is the ability to obtain an efficient and repeatable extraction using the limited quantities of material available for research in hospital biobanks. This work describes the evaluation of the peptide/protein extraction using FFPE sections treated by the following two methods before shotgun proteomic analysis: a commercial solution (FFPE-FASP) (filter aided sample preparation) and an antigen retrieval-derived protocol (On Slice AR).

Biointerface multiparametric study of intraocular lens acrylic materials.

Purpose: To compare hydrophilic and hydrophobic acrylic materials designed for intraocular lenses in a multiparametric investigation in a liquid environment to highlight their properties in terms of adhesion forces, lens epithelial cell (LEC) adhesion, and tissue response as indicators of the risk for posterior capsule opacification (PCO) development.

Setting: University of Liège, Liège, Belgium.

Design: Experimental study.

Tissue proteomics for the next decade? Towards a molecular dimension in histology.

The concept of tissues appeared more than 200 years ago, since textures and attendant differences were described within the whole organism components. Instrumental developments in optics and biochemistry subsequently paved the way to transition from classical to molecular histology in order to decipher the molecular contexts associated with physiological or pathological development or function of a tissue. In 1941, Coons and colleagues performed the first systematic integrated examination of classical histology and biochemistry when his team localized pneumonia antigens in infected tissue sections.

Glucose-, pH- and thermo-responsive nanogels crosslinked by functional superparamagnetic maghemite nanoparticles as innovative drug delivery systems.

Reversibly crosslinked (RCL) nanogels made of thermo-responsive poly(vinyl alcohol)-b-poly(N-vinylcaprolactam) copolymers were combined with maghemite nanoparticles and developed as new drug delivery systems (DDS). The crosslinking was formed via boronate/diol bonding from the surface-functionalized superparamagnetic maghemite nanoparticles, endowing the DDS with thermo-, pH- and glucose-responsiveness. The capability to load a hydrophobic drug model Nile red (NR) within the RCL nanogels was evaluated, and stimuli-triggered drug release behaviours under different conditions were tested.

Heat-triggered drug release systems based on mesoporous silica nanoparticles filled with a maghemite core and phase-change molecules as gatekeepers.

Core-shell nanoparticles made of a maghemite core and a mesoporous silica shell were developed as drug delivery systems (DDS). Doxorubicin® (DOX, DNA intercalating drug) was loaded within the mesoporous cavities, while phase-change molecules (PCMs), e.g.

Gold nanorods with phase-changing polymer corona for remotely near-infrared-triggered drug release.

Herein, we report a new drug-delivery system (DDS) that is comprised of a near-infrared (NIR)-light-sensitive gold-nanorod (GNR) core and a phase-changing poly(ε-caprolactone)-b-poly(ethylene glycol) polymer corona (GNR@PCL-b-PEG). The underlying mechanism of the drug-loading and triggered-release behaviors involves the entrapment of drug payloads among the PCL crystallites and a heat-induced phase change, respectively. A low premature release of the pre-loaded doxorubicin was observed in PBS buffer (pH 7.

Poly(acrylic acid)-block-poly(vinyl alcohol) anchored maghemite nanoparticles designed for multi-stimuli triggered drug release.

Original core/corona nanoparticles composed of a maghemite core and a stimuli-responsive polymer coating made of poly(acrylic acid)-block-poly(vinyl alcohol) macromolecules were fabricated for drug delivery system (DDS) application. This kind of DDS aims to combine the advantage of stimuli-responsive polymer coating, in order to regulate the drug release behaviours under different conditions and furthermore, improve the biocompatibility and in vivo circulation half-time of the maghemite nanoparticles. Drug loading capacity was evaluated with methylene blue (MB), a cationic model drug.

Relationships between in vitro lymphoproliferative responses and levels of contaminants in blood of free-ranging adult harbour seals (Phoca vitulina) from the North Sea.

In vitro culture of peripheral blood leucocytes (PBLs) is currently used in toxicological studies of marine mammals. However, blood cells of wild individuals are exposed in vivo to environmental contaminants before being isolated and exposed to contaminants in vitro. The aim of this study was to highlight potential relationships between blood contaminant levels and in vitro peripheral blood lymphocyte proliferation in free-ranging adult harbour seals (Phoca vitulina) from the North Sea.

Selected protein monitoring in histological sections by targeted MALDI-FTICR in-source decay imaging.

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is a rapidly growing method in biomedical research allowing molecular mapping of proteins on histological sections. The images can be analyzed in terms of spectral pattern to define regions of interest. However, the identification and the differential quantitative analysis of proteins require off line or in situ proteomic methods using enzymatic digestion.

Identification and quantification of concentration-dependent biomarkers in MCF-7/BOS cells exposed to 17β-estradiol by 2-D DIGE and label-free proteomics.

This paper reports the identification of biomarkers resulting from the exposure of MCF-7/BOS cells to 17β-estradiol (E(2)). The biomarkers were identified using 2 independent and complementary techniques, 2-D DIGE/MALDI-TOF peptide mass fingerprint, and 2-D UPLC-ESI MS/MS. They were identified from the cytosolic fractions of cells treated for 24h with mitogenic concentrations of 1, 30 and 500 pM of 17β-estradiol.