Fibronectin Conformations after Electrodeposition onto 316L Stainless Steel Substrates Enhanced Early-Stage Osteoblasts' Adhesion but Affected Their Behavior.

The implantation of metallic orthopedic prostheses is increasingly common due to an aging population and accidents. There is a real societal need to implement new metal implants that combine durability, good mechanical properties, excellent biocompatibility, as well as affordable costs. Since the functionalization of low-cost 316L stainless steel substrates through the successive electrodeposition of a polypyrrole film (PPy) and a calcium phosphate deposit doped with silicon was previously carried out by our labs, we have also developed a bio-functional coating by electrodepositing or oxidating of fibronectin (Fn) coating.

Introduction of constrained Trp analogs in RW9 modulates structure and partition in membrane models.

Over the past decades, many cell-penetrating peptides (CPP) have been studied for their capacity to cross cellular membranes, mostly in order to improve cellular uptake of therapeutic agents. Even though hydrophobic and anionic CPPs have been described, many of them are polycationic, due to the presence of several arginine (Arg) residues. Noteworthy, however, the presence of aromatic amino acids such as tryptophan (Trp) within CPPs seems to play an important role to reach high membranotropic activity.

Diffusions of sound frequencies designed to target dehydrins induce hydric stress tolerance in seedings.

Among plant responses to environmentally induced stress modulating protein expression appears to be a key stage in inducible signaling. Our study was focused on an innovative strategy to stimulate plant stress resistance, namely, the use of targeted sequences of specific sound frequencies. The influence of acoustic stimulation on plant protein synthesis was investigated.

Properties of interpenetrating polymer networks associating fibrin and silk fibroin networks obtained by a double enzymatic method.

Fibrin gels are of interest as biomaterials for regenerative medicine but present poor mechanical properties, undergo fast degradation and strongly contract in presence of cells. To face these drawbacks, a fibrin network can be associated with another polymer network, in an Interpenetrating Polymer Network (IPN) architecture. In this study, we report the properties of an IPN comprising a fibrin (Fb) network and a silk fibroin (SF) network.

Real-Time Imaging of Bacteria/Osteoblast Dynamic Coculture on Bone Implant Material in an in Vitro Postoperative Contamination Model.

Biomedical implants are an important part of evolving modern medicine but have a potential drawback in the form of postoperative pathogenic infection. Accordingly, the "race for surface" combat between invasive bacteria and host cells determines the fate of implants. Hence, proper in vitro systems are required to assess effective strategies to avoid infection.

New synthesis method of HA/P(D,L)LA composites: study of fibronectin adsorption and their effects in osteoblastic behavior for bone tissue engineering.

A novel synthetic method to synthesize hydroxyapatite/poly (D,L) lactic acid biocomposite is presented in this study by mixing only the precursors hydroxyapatite and (D,L) LA monomer without adding neither solvent nor catalyst. Three compositions were successfully synthesized with the weight ratios of 1/1, 1/3, and 3/5 (hydroxyapatite/(D,L) lactic acid), and the grafting efficiency of poly (D,L) lactic acid on hydroxyapatite surface reaches up to 84 %. Scanning electron microscopy and Fourier transform infrared spectroscopy showed that the hydroxyapatite particles were successfully incorporated into the poly (D,L) lactic acid polymer and X ray diffraction analysis showed that hydroxyapatite preserved its crystallinity after poly (D,L) lactic acid grafting.

Effects of Fibronectin Coating on Bacterial and Osteoblast Progenitor Cells Adherence in a Co-culture Assay.

Bacterial adherence to the surface of implants functionalized with cell-adhesive biomolecules is a critical first step of infection development. This study was designed to determine how the immobilization of human plasmatic fibronectin (pFN) could impact bacterial and osteoblast cells interaction with the surface during concomitant exposition to the two cell-types. Calibrated suspensions of P.

Characterization of Breast Implant Surfaces, Shapes, and Biomechanics: A Comparison of High Cohesive Anatomically Shaped Textured Silicone, Breast Implants from Three Different Manufacturers.

Unlabelled: Several companies offer anatomically shaped breast implants but differences among manufacturers are often misunderstood. The shell texture is a crucial parameter for anatomically shaped implants to prevent rotation and to decrease the risk of capsular contracture, even though concerns have recently been raised concerning the complications associated with textured breast implants. The aim of this study was to characterize differences in terms of texture, cell adhesion, shape, and stiffness between some commonly used anatomically shaped implants from three different manufacturers.

Protein covalent immobilization via its scarce thiol versus abundant amine groups: Effect on orientation, cell binding domain exposure and conformational lability.

Quantity, orientation, conformation and covalent linkage of naturally cell adhesive proteins adsorbed or covalently linked to a surface, are known to influence the preservation of their subsequent long term cell adhesion properties and bioactivity. In the present work, we explore two different strategies for the covalent linking of plasma fibronectin (pFN) - used as a cell adhesive model protein, onto a polystyrene (PS) surface. One is aimed at tethering the protein to the surface in a semi-oriented fashion (via one of the 4 free thiol reactive groups on the protein) with a heterofunctional coupling agent (SSMPB method).

Nanotemplated polyelectrolyte films as porous biomolecular delivery systems. Application to the growth factor BMP-2.

Biomaterials capable of delivering controlled quantities of bioactive agents, while maintaining mechanical integrity, are needed for a variety of cell contacting applications. We describe here a nanotemplating strategy toward porous, polyelectrolyte-based thin films capable of controlled biomolecular loading and release. Films are formed via the layer-by-layer assembly of charged polymers and nanoparticles (NP), then chemically cross-linked to increase mechanical rigidity and stability, and finally exposed to tetrahydrofuran to dissolve the NP and create an intra-film porous network.

Cell microenvironment engineering and monitoring for tissue engineering and regenerative medicine: the recent advances.

In tissue engineering and regenerative medicine, the conditions in the immediate vicinity of the cells have a direct effect on cells' behaviour and subsequently on clinical outcomes. Physical, chemical, and biological control of cell microenvironment are of crucial importance for the ability to direct and control cell behaviour in 3-dimensional tissue engineering scaffolds spatially and temporally. In this review, we will focus on the different aspects of cell microenvironment such as surface micro-, nanotopography, extracellular matrix composition and distribution, controlled release of soluble factors, and mechanical stress/strain conditions and how these aspects and their interactions can be used to achieve a higher degree of control over cellular activities.

Effects of human fibronectin and human serum albumin sequential adsorption on preosteoblastic cell adhesion.

Fibronectin (Fn) is widely reported to promote cell adhesion and spreading, and recent reports attest to the synergistic effect of coadsorbed albumin (unexpected due to the passivating character of the latter protein). In this study, the sequential adsorption of fibronectin and albumin, and the morphology of cultured MC3T3-E1 preosteoblastic cells are investigated on three important biomaterial surfaces: silicon oxide, poly(styrene) (PS), and hydroxyapatite (HA). Using quartz crystal microgravimetry with dissipation analysis, the adsorbed protein composition and mechanics are determined.

Fabrication of functional fibronectin patterns by nanosecond excimer laser direct write for tissue engineering applications.

Laser direct write techniques represent a prospective alternative for engineering a new generation of hybrid biomaterials via the creation of patterns consisting of biological proteins onto practically any type of substrate. In this paper we report on the characterization of fibronectin features obtained onto titanium substrates by UV nanosecond laser transfer. Fourier-transform infrared spectroscopy measurements evidenced no modification in the secondary structure of the post-transferred protein.

Nanofilm biomaterials: localized cross-linking to optimize mechanical rigidity and bioactivity.

Nanofilm biomaterials, formed by the layer-by-layer assembly of charged macromolecules, are important systems for a variety of cell-contacting biomedical and biotechnological applications. Mechanical rigidity and bioactivity are two key film properties influencing the behavior of contacting cells. Increased rigidity tends to improve cells attachment, and films may be rendered bioactive through the incorporation of proteins, peptides, or drugs.

Pre-osteoblasts on poly(L-lactic acid) and silicon oxide: Influence of fibronectin and albumin adsorption.

Cell adhesion and subsequent viability are critical initial steps in biomaterial-tissue integration and are strongly dependent on the material properties and the presence of matrix proteins. In the present study MC3T3-E1 osteoblast-like cell behavior on silicon oxide (SO) and poly(L-lactic acid) (PLLA) substrates has been examined, with a focus on the influence of the adhesive protein fibronectin and the non-adhesive protein albumin adsorbed on the substrates. Quartz crystal microgravimetry showed adsorption of fibronectin and albumin to be nearly identical on SO and PLLA.

Bioengineered hyaluronic acid elicited a nonantigenic T cell activation: implications from cosmetic medicine and surgery to nanomedicine.

Hyaluronan is known to act as a filling material of extracellular matrices and as an adhesive substrate for cellular migration. Consequently, it is widely used in aesthetic medicine and surgery, and it would be expected to be used in nanomedicine. Previous clinical case reports associated hyaluronic acid implants to delayed immune-mediated adverse effects.

Medical-grade silicone induces release of proinflammatory cytokines in peripheral blood mononuclear cells without activating T cells.

For more than 40 years, silicone implants had been employed in aesthetic, cosmetic medicine, and plastic surgery. Although adverse reactions produced by these products are rare, cases of immuno-mediated reactions have been reported. To evaluate the aspects of immuno-reactivity to medical-grade silicone dermal filler, peripheral blood mononuclear cells (PBMC) of 39 individuals were studied.

Contact guidance enhances the quality of a tissue engineered corneal stroma.

Corneal stroma is a very complex structure, composed of 200 lamellae of oriented collagen fibers. This highly complex nature of cornea is known to be important for its transparency and mechanical integrity. Thus, an artificial cornea design has to take into account this complex structure.

Interactions of B16F10 melanoma cells aggregated on a cellulose substrate.

There is evidence that the shape of cells and their contact with a matrix direct the growth and the differentiation of both normal and cancer cells. Cells in 3D culture resemble the in vivo situation more closely than do those in conventional 2D cultures. We have studied the interactions and functions of B16F10 mouse melanoma cells, which spread and grow well on tissue culture polystyrene (tPS), when they were made to aggregate on cellulose-coated Petri dishes (CEL).

Culture of melanoma cells as aggregates on cellulose substratum.

Cells aggregate on an original cellulose substratum (CEL). This influences the signaling programs of adhering cells. CEL thus appears to be a suitable tool for studying the regulation of cell-substratum and cell-cell interactions.

The inhibition of cell spreading on a cellulose substrate (cuprophan) induces an apoptotic process via a mitochondria-dependent pathway.

Cell shape was found to be a strong indicator of whether individual cells grow or die, and may play an important role in controlling apoptosis as well as cell growth. We compared here the behaviour of rounded Swiss 3T3 cells aggregated on a cellulose cuprophan membrane to those cultured on dish polystyrene. We demonstrated that cells aggregated on cellulose substrates for up to 48 h underwent programmed cell death that was associated with phosphatidylserine flipping and caspase 9 and caspase 3 activation, suggesting a mitochondria-dependent apoptotic process.

Comparative particle-induced cytotoxicity toward macrophages and fibroblasts.

The cytotoxicity caused by the debris resulting from wear of prostheses can produce major damage to tissues around the implant. We have compared particle internalization by macrophages and fibroblasts in vitro and analyzed cell death. J774.