Search results for "folds"

Systems level approach reveals the correlation of endoderm differentiation of mouse embryonic stem cells with specific microstructural cues of fibrin…

2014

Stem cells receive numerous cues from their associated substrate that help to govern their behaviour. However, identification of influential substrate characteristics poses difficulties because of their complex nature. In this study, we developed an integrated experimental and systems level modelling approach to investigate and identify specific substrate features influencing differentiation of mouse embryonic stem cells (mESCs) on a model fibrous substrate, fibrin. We synthesized a range of fibrin gels by varying fibrinogen and thrombin concentrations, which led to a range of substrate stiffness and microstructure. mESCs were cultured on each of these gels, and characterization of the diff…

Modular Small Diameter Vascular Grafts with Bioactive Functionalities.

2015

We report the fabrication of a novel type of artificial small diameter blood vessels, termed biomimetic tissue-engineered blood vessels (bTEBV), with a modular composition. They are composed of a hydrogel scaffold consisting of two negatively charged natural polymers, alginate and a modified chitosan, N,O-carboxymethyl chitosan (N,O-CMC). Into this biologically inert scaffold two biofunctionally active biopolymers are embedded, inorganic polyphosphate (polyP) and silica, as well as gelatin which exposes the cell recognition signal, Arg-Gly-Asp (RGD). These materials can be hardened by exposure to Ca(2+) through formation of Ca(2+) bridges between the polyanions, alginate, N,O-CMC, and polyP…

Engineering a morphogenetically active hydrogel for bioprinting of bioartificial tissue derived from human osteoblast-like SaOS-2 cells.

2014

Abstract Sodium alginate hydrogel, stabilized with gelatin, is a suitable, biologically inert matrix that can be used for encapsulating and 3D bioprinting of bone-related SaOS-2 cells. However, the cells, embedded in this matrix, remain in a non-proliferating state. Here we show that addition of an overlay onto the bioprinted alginate/gelatine/SaOS-2 cell scaffold, consisting of agarose and the calcium salt of polyphosphate [polyP·Ca 2+ -complex], resulted in a marked increase in cell proliferation . In the presence of 100 μ m polyP·Ca2+ -complex, the cells proliferate with a generation time of approximately 47–55 h. In addition, the hardness of the alginate/gelatin hydrogel substantially i…

Maltose-conjugated chitosans induce macroscopic gelation of pectin solutions at neutral pH

2014

Injectable polymer scaffolds are particularly attractive for guided tissue growth and drug/cell delivery with minimally invasive intervention. In the present work, "all-polymeric" gelling systems based on pectins and water-soluble maltose-conjugated chitosans (CM) have been developed. Maltose-conjugated chitosan has been synthesized at three different molar ratios, as evaluated by FITR analysis and fluorimetric titration. A thorough rheological characterization of the blends and their parent solutions has been performed. Macroscopic gelation has been achieved by mixing the high esterification degree pectins with CM at higher maltose grafted to chitosan contents. Gels form in a few minutes a…

Bidirectional cell-matrix interaction dictates neuronal network formation in a brain-mimetic 3D scaffold

2022

Human pluripotent stem cells (hPSC) derived neurons are emerging as a powerful tool for studying neurobiology, disease pathology, and modeling. Due to the lack of platforms available for housing and growing hPSC-derived neurons, a pressing need exists to tailor a brain-mimetic 3D scaffold that recapitulates tissue composition and favourably regulates neuronal network formation. Despite the progress in engineering biomimetic scaffolds, an ideal brain-mimetic scaffold is still elusive. We bioengineered a physiologically relevant 3D scaffold by integrating brain-like extracellular matrix (ECM) components and chemical cues. Culturing hPSCs-neurons in hyaluronic acid (HA) gels and HA-chondroitin…

HYALURONIC ACID-graft-ELASTIN BASED SCAFFOLDS FOR POTENTIAL TISSUE ENGINEERING APPLICATIONS

2012

Dehydrogenation behaviour of mixed borohydrides dispersed on high specific surface area carbons

2011

Micro-architecture of three-dimensional porous scaffolds evaluated via image processing technique

2011

Technique des membranes induites en chirurgie maxillo-faciale

2012

Maxillofacial defects reconstruction represents a formidable challenge to achieve both functional and aesthetic goals. To succeed, numerous parameters must be taken into account: patient's general conditions, defect's location, width and type of the defect and eventual donor sites which can provide the tissues. Routine reconstructions include bone transplantation (autologous, homologous or heterologous), implantation of biomaterials and osteogenic distraction. The advantages of these techniques are evident, but they are usually limited by their complexity in patients with bad general health. The technique of induced membranes needs to be more known in maxillofacial surgery.

BMP-2 and bFGF release and in vitro effect on human osteoblasts after adsorption to bone grafts and biomaterials.

2012

Objectives Combination of scaffolds and growth factors is a promising option for several clinical problems in bone biomaterials. Simplified growth factor loading by adsorption from aqueous solution is one important option for this technology. We evaluated the adsorption followed by PBS rinsing, release and biological effect of transient loading with basic fibroblast growth factor (bFGF) and bone morphogenic protein 2 (BMP-2) on fresh frozen bone, processed bone matrix, collagen, and a ceramic material with immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and qRT-PCR. Materials and methods The study consisted of three in vitro experiments (immunofluorescence, ELISA, and qRT-PCR…