Deficiency of the SMOC2 matricellular protein impairs bone healing and produces age-dependent bone loss.

Secreted extracellular matrix components which regulate craniofacial development could be reactivated and play roles in adult wound healing. We report a patient with a loss-of-function of the secreted matricellular protein SMOC2 (SPARC related modular calcium binding 2) presenting severe oligodontia, microdontia, tooth root deficiencies, alveolar bone hypoplasia, and a range of skeletal malformations. Turning to a mouse model, Smoc2-GFP reporter expression indicates SMOC2 dynamically marks a range of dental and bone progenitors.

Functionalization of PTFE Materials Using a Combination of Polydopamine and Platelet-Rich Fibrin.

Background: The diaphragm, which forms a physical barrier between the thoracic and the abdominal cavities, is also the major part of the respiratory system. Congenital diaphragmatic hernia (CDH) is a malformation of that partition muscle. Expanded polytetrafluoroethylene (e-PTFE), a synthetic nondegradable biomaterial, is currently used for the repair of diaphragm defects.

Technical Quality of Root Canal Filling in Preclinical Training at Strasbourg University Using Two Teaching Protocols.

Objectives:  The aim of this study was to compare two teaching protocols according to the technical quality of root canal therapy (RCT) and the procedural errors occurred in preclinical training.

Materials And Methods:  Two different groups of students were concerned. The first one (G1) performed a crown-down technique to shape the root canal systems and cold lateral condensation technique to fill them.

Effectiveness of Etching by Three Acids on the Morphological and Chemical Features of Dentin Tissue.

Aim: The purpose of this study was to evaluate the microscopic and chemical effects of phosphoric acid gel, phosphoric acid liquid, and polyacrylic acid application for 15 seconds (s) on coronal dentin.

Materials And Methods: Twelve extracted teeth were selected. Three etching acids were used to prepare the dentin surfaces.

Effect of etching the coronal dentin with the rubbing technique on the microtensile bond strength of a universal adhesive system.

Background: The adhesion of composite resins to the dentin substrate is influenced by the treatment of the smear layer. While etch-and-rinse systems require dentin to be conditioned with phosphoric acid, self-etching systems preserve the smear layer by incorporating it into the adhesive layer.

Objectives: The objective of this study was to evaluate the influence of etching with the rubbing technique on the microtensile bond strength (μTBS) of a universal adhesive to dentin.

Microscopic and Chemical Assessments of the Filling Ability in Oval-Shaped Root Canals Using Two Different Carrier-Based Filling Techniques.

Objectives: The aim of this study was to assess the filling ability in oval-shaped canals using two different carrier-based filling techniques.

Materials And Methods: Twenty-four human mandibular premolars with one oval canal were selected. Canals were shaped using WaveOne Gold Primary and ProGlider.

Polydopamine Functionalization: A Smart and Efficient Way to Improve Host Responses to e-PTFE Implants.

Among the different materials used as protheses for the treatment of Congenital Diaphragmatic Hernia, expanded polytetrafluoroethylene (e-PTFE) plays a leading role owing to its mechanical properties as explained in the first part of this review. However, this material is poorly cell adhesive, which is expected for its contact on the abdominal face, but should display specific tissue adhesion on its thoracic exposed faced. A side specific functionalization method is hence required.

A New Homozygous Missense Mutation Responsible for a Milder Phenotype of Skeletal Dysplasia With Amelogenesis Imperfecta.

Amelogenesis imperfecta (AI) is a heterogeneous group of rare inherited diseases presenting with enamel defects. More than 30 genes have been reported to be involved in syndromic or non-syndromic AI and new genes are continuously discovered (Smith et al., 2017).

Electrochemistry on Stretchable Nanocomposite Electrodes: Dependence on Strain.

Stretchable nanocomposite conductors are essential for engineering of bio-inspired deformable electronics, human-machine interfaces, and energy storage devices. While the effect of strain on conductivity for stretchable conductors has been thoroughly investigated, the strain dependence of multiple other electrical-transport processes and parameters that determine the functionalities and biocompatibility of deformable electrodes has received virtually no attention. The constancy of electrochemical parameters at electrode-fluid interfaces such as redox potentials, impedances, and charge-transfer rate constants on strain is often tacitly assumed.

Boric Acid as an Efficient Agent for the Control of Polydopamine Self-Assembly and Surface Properties.

The deposition of polydopamine (PDA) films on surfaces, a versatile deposition method with respect to the nature of the used substrate, is unfortunately accompanied by deposition of insoluble precipitates in solution after a prolonged oxidation time of dopamine solutions. Therefore, there is evident interest to find methods able to stop the deposition of PDA on surfaces and to simultaneously control the self-assembly of PDA in solution to get stable colloidal aggregates. In addition to proposed methods relying on the use of polymers like poly(vinyl alcohol) and proteins like human serum albumin, we show herein that boric acid is an efficient adjuvant that is simultaneously able to stop the self-assembly of PDA in solution as well as on surfaces and to change the adhesive properties of the resulting PDA coatings.

Control of Surface-Localized, Enzyme-Assisted Self-Assembly of Peptides through Catalyzed Oligomerization.

Localized self-assembly allowing both spatial and temporal control over the assembly process is essential in many biological systems. This can be achieved through localized enzyme-assisted self-assembly (LEASA), also called enzyme-instructed self-assembly, where enzymes present on a substrate catalyze a reaction that transforms noninteracting species into self-assembling ones. Very few LEASA systems have been reported so far, and the control of the self-assembly process through the surface properties represents one essential step toward their use, for example, in artificial cell mimicry.

Retinoic Acid Excess Impairs Amelogenesis Inducing Enamel Defects.

Abnormalities of enamel matrix proteins deposition, mineralization, or degradation during tooth development are responsible for a spectrum of either genetic diseases termed or acquired enamel defects. To assess if environmental/nutritional factors can exacerbate enamel defects, we investigated the role of the active form of vitamin A, retinoic acid (RA). Robust expression of RA-degrading enzymes and in developing murine teeth suggested RA excess would reduce tooth hard tissue mineralization, adversely affecting enamel.

Enamel and dental anomalies in latent-transforming growth factor beta-binding protein 3 mutant mice.

Latent-transforming growth factor beta-binding protein 3 (LTBP-3) is important for craniofacial morphogenesis and hard tissue mineralization, as it is essential for activation of transforming growth factor-β (TGF-β). To investigate the role of LTBP-3 in tooth formation we performed micro-computed tomography (micro-CT), histology, and scanning electron microscopy analyses of adult Ltbp3-/- mice. The Ltbp3-/- mutants presented with unique craniofacial malformations and reductions in enamel formation that began at the matrix formation stage.

New insight in the biological integration of polytetrafluoroethylene from an explant used for diaphragm repair.

Congenital diaphragmatic hernia is a severe disease requiring diaphragm replacement mostly with expanded polytetrafluoroethylene. Unfortunately, the recurrence rate is high due to prosthesis failure with significant morbidity for the child. To provide a better understanding of the integration and possible failure processes of the biomaterial implanted in humans, we conducted electron microscopical and mechanical assessments on a prosthesis explant from a child with congenital diaphragmatic hernia presenting a recurrence.

Aberration-Corrected Transmission Electron Microscopic Study of the Central Dark Line Defect in Human Tooth Enamel Crystals.

Angstrom resolution images of human tooth enamel (HTE) crystallites were obtained using aberration-corrected high-resolution transmission electron microscopy and atomic-resolution scanning transmission electron microscopy in the modes of bright field, annular dark field, and high-angle annular dark-field. Images show that the central dark line (CDL) defect observed around the center of the HTE crystals is a site for caries formation in the HTE and has a thickness of ~0.2 nm.

Computed Tomographic Study of the Pediatric Diaphragmatic Growth: Application to the Treatment of Congenital Diaphragmatic Hernia.

 The prosthesis commonly used for the treatment of congenital diaphragmatic hernia (CDH) lacks elasticity to replace the diaphragm's mechanical properties and does not follow the natural growth of the child treated.  To determine the appropriate properties required for the prostheses, a CT study on healthy patients was conducted.  Two methods of diaphragmatic surface analysis are assessed: the diaphragmatic surface is either estimated using surface 2D estimations (method 1), or calculated using length measures on thoracoabdominal CT scans from children (method 2).

Airway administration of a highly versatile peptide-based liposomal construct for local and distant antitumoral vaccination.

With the discovery of tumor-associated antigens such as ErbB2, vaccination is considered as a promising strategy to prevent the development of cancer or treat the existing disease. Among routes of immunization, the respiratory route provides the opportunity to develop non-invasive approach for vaccine delivery. In the current study, this administration route was used in order to investigate the potency of a highly versatile di-epitopic liposomal construct to exhibit local or distant antitumoral efficiency after prophylactic or therapeutic vaccination in mice.

Generating and characterizing the mechanical properties of cell-derived matrices using atomic force microscopy.

Mechanical interaction between cells and their surrounding extracellular matrix (ECM) controls key processes such as proliferation, differentiation and motility. For many years, two-dimensional (2D) models were used to better understand the interactions between cells and their surrounding ECM. More recently, variation of the mechanical properties of tissues has been reported to play a major role in physiological and pathological scenarios such as cancer progression.

Polydopamine Films from the Forgotten Air/Water Interface.

The formation of polydopamine under mild oxidation conditions from dopamine solutions with mechanical agitation leads to the formation of films that can functionalize all kinds of materials. In the absence of stirring of the solution, we report the formation of polydopamine films at the air/water interface (PDA A/W) and suggest that it arises from an homogeneous nucleation process. These films grow two times faster than in solution and can be deposited on hydrophilic or hydrophobic substrates by the Langmuir-Schaeffer technique.

Priming cells for their final destination: microenvironment controlled cell culture by a modular ECM-mimicking feeder film.

Mammalian cell culture is the starting point in many research studies focusing on biomedical applications. However, researchers have little control over the standardized cell microenvironment parameters. Here a modular ECM-mimicking surface coating for cell culture environment is designed.

Bioactive Seed Layer for Surface-Confined Self-Assembly of Peptides.

The design and control of molecular systems that self-assemble spontaneously and exclusively at or near an interface represents a real scientific challenge. We present here a new concept, an active seed layer that allows to overcome this challenge. It is based on enzyme-assisted self-assembly.

Correction: Multivalency: influence of the residence time and the retraction rate on rupture forces measured by AFM.

Correction for 'Multivalency: influence of the residence time and the retraction rate on rupture forces measured by AFM' by Jalal Bacharouche et al., J. Mater.

Multivalency: influence of the residence time and the retraction rate on rupture forces measured by AFM.

The Bell-Evans theory relative to rupture forces between non-covalently interacting molecules predicts that the rupture force increases linearly with the logarithm of the force loading rate. Here we investigate by force spectroscopy performed with an atomic force microscope (AFM) the rupture forces between surfaces covered by β-cyclodextrin (β-CD) molecules and AFM tips coated with adamantane (AD) groups. The β-CD molecules are either deposited through a self-assembled monolayer (SAM) or grafted on poly(allylamine hydrochloride) chains (PAH-CD) that are adsorbed on the substrate.

A new biomimetic route to engineer enzymatically active mechano-responsive materials.

Using modified β-galactosidase covalently linked to cross-linked polyelectrolyte multilayers (PEM), catalytically active materials have been designed. Their enzymatic activity can be modulated, partially in a reversible way, simply by stretching. This strategy, based on enzyme conformational changes, constitutes a new tool for the development of biocatalytic mechano-responsive materials.

Mutations in the latent TGF-beta binding protein 3 (LTBP3) gene cause brachyolmia with amelogenesis imperfecta.

Inherited dental malformations constitute a clinically and genetically heterogeneous group of disorders. Here, we report on four families, three of them consanguineous, with an identical phenotype, characterized by significant short stature with brachyolmia and hypoplastic amelogenesis imperfecta (AI) with almost absent enamel. This phenotype was first described in 1996 by Verloes et al.