Adaptive responses of murine osteoblasts subjected to coupled mechanical stimuli.

Restitution of the natural organization and orientation of cells is imperative for the construction of functional tissue scaffolds. While numerous studies have exploited mechanical methods to engineer tissues with the desired cellular architecture, fundamental knowledge is still lacking in understanding the manner in which morphological features can be modulated through coupled mechanical cues. To address this knowledge gap, the adhesion and alignment response of murine osteoblast cells under the synergistic effects of matrix rigidity and cyclic mechanical loading was investigated.

Vinculin expression in MC3T3-E1 cells in response to mechanical stimulus.

Loading frequency is known to influence the expression of the focal adhesions of the adherent cells. A small cyclical tensile force was transmitted to mouse pre-osteoblast MC3T3-E1 cells through PDMS substrates of varying stiffness. Changes in cell behavior with respect to proliferation and characteristics of focal adhesions were quantified through immunofluorescence labeling of vinculin.

Titanium Oxide: A Bioactive Factor in Osteoblast Differentiation.

Titanium and titanium alloys are currently accepted as the gold standard in dental applications. Their excellent biocompatibility has been attributed to the inert titanium surface through the formation of a thin native oxide which has been correlated to the excellent corrosion resistance of this material in body fluids. Whether this titanium oxide layer is essential to the outstanding biocompatibility of titanium surfaces in orthopedic biomaterial applications is still a moot point.

Electrochemical characterization of MC3T3-E1 cells cultured on γTiAl and Ti-6Al-4V alloys.

Electrochemical impedance spectroscopy (EIS) was used to study the behavior of MC3T3-E1 cells cultured in an αMEM+FBS solution on two Ti-based alloys (Ti-6Al-4V and γTiAl) for 4, 7 and 14 days. EIS measurements were carried out at an open-circuit potential in a 1 mHz to 100 kHz frequency range. Results indicate a general increase in impedance on the Ti alloy surfaces with cells as a function of time.

The effects of micro arc oxidation of gamma titanium aluminide surfaces on osteoblast adhesion and differentiation.

The adhesion and proliferation of human fetal osteoblasts, hFOB 1.19, on micro arc oxidized (MAO) gamma titanium aluminide (γTiAl) surfaces were examined in vitro. Cells were seeded on MAO treated γTiAl disks and incubated for 3 days at 33.

Plasma electrolytic oxidation coatings on γTiAl alloy for potential biomedical applications.

In an attempt to enhance the potential of gamma titanium aluminide intermetallic alloy as a biomaterial, its surface characteristics were successfully modified using a calcium and phosphorous rich electrolyte through the application of plasma electrolytic oxidation. Scanning electron microscopy and atomic force microscopy were used to characterize the morphology and topographical features of the resulting coating while X-ray diffraction and energy dispersive spectroscopy were used to determine the surface oxide composition. The mechanical properties of the surface coating were characterized by nanoindentation studies.

Collagen abundance in mechanically stimulated osteoblast cultures using near infrared microscopy.

Collagen abundance in osteoblast cell cultures was determined using near infrared microscopy with chemical imaging (NIR-CI) with and without mechanical stimulation of the the cells. MC3T3-E1 mouse osteoblast cells seeded on a polycarbonate substrate were mechanically stimulated using static loads of 13.5 N, 27 N and 40 N applied to the substrates during 2, 4, 6 and 8 days of incubation.

Tribological properties of Ti-based alloys in a simulated bone-implant interface with Ringer's solution at fretting contacts.

The wear properties of oxidized and non-oxidized gamma-TiAl (a potential biomaterial) as well as Ti-6Al-4V and CP-Ti disks were studied and characterized by means of standard wear tests using a custom made bone pin arrangement. The Ti-based disks were oxidized in air at 500 and 800 degrees C for one hour. The tribological properties of the oxides formed over the disks were studied using a linear reciprocating wear testing machine under both dry and simulated biological conditions using Ringer's solution.

In vitro evaluation of human osteoblast adhesion to a thermally oxidized gamma-TiAl intermetallic alloy of composition Ti-48Al-2Cr-2Nb (at.%).

Ti-48Al-2Cr-2Nb (at.%) (gamma-TiAl), a gamma titanium aluminide alloy originally designed for aerospace applications, appears to have excellent potential as implant material. Thermal treatment of gamma-TiAl renders this alloy extremely corrosion resistant in vitro, which could improve its biocompatibility.

Biocompatibility studies of human fetal osteoblast cells cultured on gamma titanium aluminide.

Ti-48Al-2Cr-2Nb (at. %) (gammaTiAl), a gamma titanium aluminide alloy originally designed for aerospace applications, appears to have excellent potential for bone repair and replacement. The biological response to gammaTiAl implant is expected to be similar to other titanium-based biomaterials.

Possible active origin of replication in the double stranded extended form of the left terminus of LuIII and its implication on the replication model of the parvovirus.

Background: The palindromic termini of parvoviruses have proven to play an essential role as origins of replication at different stages during the replication of their viral genome. Sequences from the left-end telomere of MVM form a functional origin on one side of the dimer replicative form intermediate. In contrast, the right-end origin can operate in its closed replicative form hairpin configuration or as a fully duplex linear sequence derived from either arm of a palindromic tetramer intermediate.