Search results for "Biomaterial"

Adhesion prophylaxis using a copolymer with rationally designed material properties.

2008

Physical barriers are the only licensed adjuncts for adhesion prophylaxis in the United States and Europe. Here, we investigate D,L-polylactide-epsilon-caprolactonetrimethylenecarbonate (PCT copolymer), which is a rationally designed biomaterial, as an adhesion barrier.PCT copolymer membranes were produced by polymerization of the monomers, dissolution in organic solvents, and subsequently processing them by means of modified phase inversion and freeze drying. In vitro cytotoxicity was assayed by fibroblast culture. In vivo adhesion prophylaxis was studied in a rat model that involved standardized traumatization by electrocautery and suturing. The quantity and quality of the resulting adhes…

Cardiac tissue engineering: a reflection after a decade of hurry

2014

The heart is a perfect machine whose mass is mainly composed of cardiomyocytes, but also fibroblasts, endothelial, smooth muscle, nervous, and immune cells are represented. One thousand million cardiomyocytes are estimated to be lost after myocardial infarction, their loss being responsible for the impairment in heart contractile function (Laflamme and Murry, 2005). The potential success of cardiac cell therapy relies almost completely on the ability of the implanted cells to differentiate toward mature cardiomyocytes. These cells must be able to reinforce the pumping activity of the injured heart in the absence of life-threatening arrhythmias due to electrophysiological incompatibility. Th…

Patient-specific simulation of the intrastromal ring segment implantation in corneas with keratoconus

2015

Purpose The purpose of this study was the simulation of the implantation of intrastromal corneal-ring segments for patients with keratoconus. The aim of the study was the prediction of the corneal curvature recovery after this intervention. Methods Seven patients with keratoconus diagnosed and treated by implantation of intrastromal corneal-ring segments were enrolled in the study. The 3D geometry of the cornea of each patient was obtained from its specific topography and a hyperelastic model was assumed to characterize its mechanical behavior. To simulate the intervention, the intrastromal corneal-ring segments were modeled and placed at the same location at which they were placed in the s…

Nanocarrier based on halloysite and fluorescent probe for intracellular delivery of peptide nucleic acids

2022

The development of systems able to deliver genetic material into a target site is a challenge for modern medicine. Single-stranded peptide nucleic acids have attracted attention as promising therapeutic molecules for diagnostic and gene therapy. However, their poor cell membrane permeability represents a drawback for biomedical applications. Halloysite nanotubes (HNTs) are emerging materials in drug delivery applications both for their ability to penetrate cell membranes and for enhancing the solubility of drugs in biological media. Herein, we report the first example of the use of a nanocarrier based on halloysite labelled with fluorescent switchable halochromic oxazine molecules, to deliv…

Mesenchymal dental stem cells in regenerative dentistry

2012

In the last decade, tissue engineering is a field that has been suffering an enormous expansion in the regenerative medicine and dentistry. The use of cells as mesenchymal dental stem cells of easy access for dentist and oral surgeon, immunosuppressive properties, high proliferation and capacity to differentiate into odontoblasts, cementoblasts, osteoblasts and other cells implicated in the teeth, suppose a good perspective of future in the clinical dentistry. However, is necessary advance in the known of growth factors and signalling molecules implicated in tooth development and regeneration of different structures of teeth. Furthermore, these cells need a fabulous scaffold that facility t…

Biologization of Allogeneic Bone Grafts with Polyphosphate: A Route to a Biomimetic Periosteum

2019

Complex permittivity of FeCl3/AOT/CCl4 microemulsions probed by AC impedance spectroscopy

2009

Abstract The complex permittivity of FeCl 3 /AOT/CCl 4 microemulsions in the 1–10 5  Hz frequency range has been measured by the conventional AC complex impedance technique. Measurements as a function of the volume fraction of the dispersed phase (FeCl 3  + AOT) and temperature at fixed salt-to-AOT molar ratio ( R , R  = 0.5) show that the entrapment of FeCl 3 clusters significantly enhances the local permittivity of the AOT reverse micelles and the number density of charge carriers resulting from the peculiar state of the confined inorganic salt. An estimate of the apparent static permittivity of the FeCl 3 ionic clusters entrapped in the core of AOT reverse micelles gives the very high an…

Pectin biopolymer mechanics and microstructure associated with polysaccharide phase transitions.

2019

Polysaccharide polymers like pectin can demonstrate striking and reversible changes in their physical properties depending upon relatively small changes in water content. Recent interest in using pectin polysaccharides as mesothelial sealants suggests that water content, rather than nonphysiologic changes in temperature, may be a practical approach to optimize the physical properties of the pectin biopolymers. Here, we used humidified environments to manipulate the water content of dispersed solution of pectins with a high degree of methyl esterification (high-methoxyl pectin; HMP). The gel phase transition was identified by a nonlinear increase in compression resistance at a water content …

Melting and interdigitation of microstructured solid supported membranes quantified by imaging ellipsometry

2010

The phase transition of individually addressable microstructured lipid bilayers was investigated by means of noncontact imaging ellipsometry. Two-dimensional membrane compartments were created on silicon substrates by micromolding in capillaries and the phase transition of supported dimyristoylphosphadiylcholine DMPC and dipentadecoylphosphatidylcholine DiC15PC membranes was determined measuring area expansion and thickness of the bilayer as a function of temperature, ethanol concentration, and cholesterol content. Apart from measuring the thermotropic behavior of DMPC on glass slides and silicon wafers, the authors were able to visualize the reversible induction of an interdigitated phase …

Pathogen-Mimicking MnO Nanoparticles for Selective Activation of the TLR9 Pathway and Imaging of Cancer Cells

2009

Here, design of the first pathogen-mimicking metal oxide nanoparticles with the ability to enter cancer cells and to selectively target and activate the TLR9 pathway, and with optical and MR imaging capabilities, is reported. The immobilization of ssDNA (CpG ODN 2006) on MnO nanoparticles is performed via the phosphoramidite route using a multifunctional polymer. The multifunctional polymer used for the nanoparticle surface modification not only affords a protective organic biocompatible shell but also provides an efficient and convenient means for loading immunostimulatory oligonucleotides. Since fluorescent molecules are amenable to photodetection, a chromophore (Rhodamine) is introduced …