Bioactive micropatterning of biomaterials for induction of endothelial progenitor cell differentiation: Acceleration of in situ endothelialization.

Synthetic grafts do not provide an appealing surface for endothelial cells to adhere and colonize the inner surface. To promote in situ endothelialization the following aspect has to be taken into account, endothelial progenitor cells (EPCs) needs to be mobilized on the surface of the graft. The surface of the graft has to be sufficiently biocompatible to create a prone environment for the EPCs to adhere, proliferate and, differentiate to form a layer and subsequently improve graft patency.

Dendron-Functionalized Surface: Efficient Strategy for Enhancing the Capture of Microvesicles.

Microvesicles (MVs) are used by various types of cells in the human body for intercellular communication, making them biomarkers of great potential for the early and non-evasive diagnosis of a spectrum of diseases. An integrated analysis including morphological, quantitative, and compositional studies is most desirable for the clinical application of MV detection; however, such integration is limited by the currently available analysis techniques. In this context, exploiting the phosphatidylserine (PS) exposure of MVs, we synthesized a series of dendritic molecules with PS-binding sites at the periphery.

Directing hMSCs fate through geometrical cues and mimetics peptides.

The native microenvironment of mesenchymal stem cells (hMSCs)-the extracellular matrix (ECM), is a complex and heterogenous environment structured at different scales. The present study aims at mimicking the hierarchical microorganization of proteins or growth factors within the ECM using the photolithography technique. Polyethylene terephthalate substrates were used as a model material to geometrically defined regions of RGD + BMP-2 or RDG + OGP mimetic peptides.

Single or Mixed Tethered Peptides To Promote hMSC Differentiation toward Osteoblastic Lineage.

The commitment and differentiation of human mesenchymal stem cells (hMSCs) are guided by bioactive molecules within the extracellular matrix. Among the various approaches to design biomaterials, the functionalization of biomaterial surfaces with peptides from the sequence of proteins from the extracellular matrix is quite common. The purpose of this functionalization is to recruit hMSCs and promote their differentiation into the appropriate lineage.

Modulation of lumen formation by microgeometrical bioactive cues and migration mode of actin machinery.

How endothelial cells (ECs) express the particular filopodial or lamellipodial form of the actin machinery is critical to understanding EC functions such as angiogenesis and sprouting. It is not known how these mechanisms coordinately promote lumen formation of ECs. Here, adhesion molecules (RGD peptides) and inductor molecules (BMP-2 mimetic peptides) are micropatterned onto polymer surfaces by a photolithographic technique to induce filopodial and lamellipodial migration modes.

Altered nanofeature size dictates stem cell differentiation.

The differentiation of stem cells can be modulated by physical factors such as the micro- and nano-topography of the extracellular matrix. One important goal in stem cell research is to understand the concept that directs differentiation into a specific cell lineage in the nanoscale environment. Here, we demonstrate that such paths exist by controlling only the micro- and nano-topography of polymer surfaces.

The effect of RGD density on osteoblast and endothelial cell behavior on RGD-grafted polyethylene terephthalate surfaces.

Hybrid materials combining polyethylene terephthalate and different types of cells (endothelial and osteoblastic cells) have been developed thanks to the covalent grafting of different densities of RGD containing peptides onto the polymer surface. Biomimetic modifications were performed by means of a three-step reaction procedure: creation of COOH functions, coupling agent grafting and the immobilization of the RGDC peptides. High resolution mu-imager was used to evaluate RGD densities (varying between 0.