Osteoconductivity of Porous Titanium Having Young’s Modulus Similar to Bone and Surface Modification by OCP

2007 ◽  
Vol 330-332 ◽  
pp. 951-954 ◽  
Author(s):  
Yuko Suzuki ◽  
Naoyuki Nomura ◽  
Shuji Hanada ◽  
Shinji Kamakura ◽  
Takahisa Anada ◽  
...  

The present study was designed to investigate whether porous titanium (Ti) having Young’s modulus similar to bone has osteoconductive characteristics in rat critical-sized calvarial bone defect. The effect of coating by octacalcium phosphate (OCP) was also examined. OCP is known as a precursor of initial mineral crystals of biological apatite in bones and teeth. Ti powder was prepared by plasma rotating electrode process in an Ar atmosphere. Then, porous Ti disks, 8 mm in diameter with 1 mm thick, were obtained using the particles ranging from 300 to 500 +m, by sintering at 1573 K without applied pressure. The disks had about 35 vol% in porosity and about 10 GPa in Young’s modulus which corresponds to that of human cortical bone. Newly formed bone was observed so as to fill the pore up at 12 weeks, confirming the ability to conduct the ingrowths of the bone tissue. Although in vitro study showed that proliferation of mouse bone marrow stromal ST-2 cells was inhibited on the dishes coated by OCP rather than the control dish, OCP coating on porous Ti seemed to stimulate the bone formation in vivo. Taken together, it seems likely that porous Ti having Young’s modulus similar to bone shows osteoconductive characteristics to conduct bone ingrowths. OCP could be a potential coating agent to assist bone regeneration on porous Ti.

2006 ◽  
Vol 975 ◽  
Author(s):  
Andrei Stanishevsky ◽  
Shafiul Chowdhury ◽  
Nathaniel Greenstein ◽  
Helene Yockell-Lelievre ◽  
Jari Koskinen

ABSTRACTThe hydroxyapatite (HA) based bioceramic materials are usually prepared at high sintering temperatures to attain suitable mechanical properties. The sintering process usually results in a material which is compositionally and morphologically different from nonstoichiometric nano-crystalline HA phase of hard tissue. At the same time, HA particulates used as precursors in ceramic manufacturing are often very similar to the natural HA nanocrystals. It has been shown that synthetic nanoparticle HA (nanoHA) based materials improve the biological response in vitro and in vivo, but the information on mechanical properties of these materials is scarce.In this work we studied the HA nanoparticle (10 – 80 nm mean size) coatings with 30 – 70% porosity prepared by a dip-coating technique on Ti and TiN substrates. It has been found that the mechanical properties of HA nanoparticle coatings are strongly influenced by the initial size, morphology, and surface treatment of nanoparticles. The nanoindentation Young's modulus and hardness of as–deposited nanoHA coatings were in the range of 2.5 – 6.9 GPa and 80 – 230 MPa, respectively. The coatings were stable after annealing up to at least 600 °C, reaching the Young's modulus up to 23 GPa and hardness up to 540 MPa, as well as in simulated body fluids.


RSC Advances ◽  
2020 ◽  
Vol 10 (40) ◽  
pp. 23582-23591
Author(s):  
Xin Liu ◽  
Yumei Niu ◽  
Weili Xie ◽  
Daqing Wei ◽  
Qing Du

To avoid the failure of clinical surgery due to “stress shielding” and the loosening of an implant, a new type of alloy, Ti–24Nb–4Zr–8Sn (TNZS), with a low Young's modulus acted as a new implant material in this work.


1979 ◽  
Vol 1 (4) ◽  
pp. 356-367 ◽  
Author(s):  
D.J. Hughes ◽  
C.F. Babbs ◽  
L.A. Geddes ◽  
J.D. Bourland

We have developed an ultrasonic technique for determining the dynamic Young's modulus of elasticity (E) of the canine aorta in vivo. Young's modulus was measured in the descending thoracic aorta (DTA) and the abdominal aorta (AA) of 12 dogs over a range of mean blood pressures from 40 – 200 mm Hg. The vessels were excised and dynamic moduli were determined in vitro post-mortem from pressure-volume curves. The data so obtained were compared to the in vivo values. In vivo and in vitro moduli increased exponentially with mean distending pressure (P). The equation of best fit for these data was of the form E = R0 exp(aP). E0 and a depend on the site of measurement (AA or DTA) and upon the particular animal. In vivo and in vitro moduli were not significantly different in the AA (AA: in vivo E0 = 667 ± 382 mm Hg, a = 0.017 ± 0.004 mm Hg-1 in vitro E0 = 888 ± 367, a = 0.016 ± 0.002). However, in vivo moduli exceeded in vitro moduli in the DTA. (DTA: in vivo E0 = 687 ± 241, a = 0.016 ± 0.004 in vitro E0 = 349 ± 64, a = 0.018 ± 0.003). The increased stiffness of the DTA compared to the AA in vivo may be due to the in situ tethering of the aorta to the spine by the parietal pleura.


2011 ◽  
Vol 217-218 ◽  
pp. 1191-1196
Author(s):  
Peng Zhang ◽  
Yuan Chen Qi ◽  
Wei Li

Porous titanium compacts were fabricated by powder metallurgy using cold isostatic press with and without pore forming agents. Their microstructure and mechanical properties were investigated in this study. These alloy powders were sintered under 1300°C in vacuum of 10-3 Pa for 2h, followed by furnace cooling. Young’s modulus of sintered Ti could equal that of human’s dense bones. It was found that the strength of porous Ti enhanced by increasing the pressure or decreasing the amounts of pore forming agents. We prepared a porous pure Ti with 30wt.% NH4HCO3 as pore forming agents whose modulus was near to the human cortical bone, as compared in the range from 10 to 30GPa of Young’s modulus for human bone.


RSC Advances ◽  
2018 ◽  
Vol 8 (64) ◽  
pp. 36512-36520 ◽  
Author(s):  
Ji Li ◽  
Zhongli Li ◽  
Ruiling Li ◽  
Yueyi Shi ◽  
Haoran Wang ◽  
...  

The sintered porous Ti6Al4V with 75% porosity has optimal mechanical properties, good biocompatibility and osteogenic ability for more bone ingrowth.


1997 ◽  
Vol 87 (6) ◽  
pp. 266-271 ◽  
Author(s):  
LA Lavery ◽  
SA Vela ◽  
HR Ashry ◽  
DR Lanctot ◽  
KA Athanasiou

Viscoelastic inserts are commonly used as artificial shock absorbers to prevent neuropathic foot ulcerations by decreasing pressure on the sole of the foot. Unfortunately, there is little scientific information available to guide physicians in the selection of appropriate insole materials. Therefore, a novel methodology was developed to form a rational platform for biomechanical characterizations of insole material durability, which consisted of in vivo gait analysis and in vitro bioengineering measurements. Results show significant differences in the compressive stiffness of the tested insoles and the rate of change over time in both compressive stiffness and peak pressures measured. Good correlations were found between pressure-time integral and Young's modulus (r2 = 0.93), and total energy applied and Young's modulus (r2 = 0.87).


2007 ◽  
Vol 539-543 ◽  
pp. 1033-1037 ◽  
Author(s):  
Naoyuki Nomura ◽  
Y. Baba ◽  
A. Kawamura ◽  
S. Fujinuma ◽  
Akihiko Chiba ◽  
...  

Porous Ti compacts reinforced by ultra-high molecular weight polyethylene (UHMWPE) were fabricated and their mechanical properties were evaluated. Ti powder atomized by plasma rotating electrode process (PREP) was sintered at temperatures ranging from 1473 K to 1673 K for 7.2 ks in a vacuum. The porous Ti compacts contain the porosity of about 40%, irrespective of the sintering temperature. Porous Ti/UHMWPE composites were successfully fabricated by compressing UHMWPE powder into the porous Ti compacts. The compacts exhibit open pore structure and enables the penetration of UHMWPE into pores in the compacts. Young’s modulus of the composites is higher than that of the porous Ti compacts. The increment in Young’s modulus is not simply explained by the rule of mixture because Young’s modulus of the UHMWPE is approximately 1.3 GPa. Three-point bending strength of the composites is improved, presumably due to the local stress relief by UHMWPE in the vicinity of neck in the composites.


2012 ◽  
Vol 112 (3) ◽  
pp. 419-426 ◽  
Author(s):  
René B. Svensson ◽  
Philip Hansen ◽  
Tue Hassenkam ◽  
Bjarki T. Haraldsson ◽  
Per Aagaard ◽  
...  

Tendons are strong hierarchical structures, but how tensile forces are transmitted between different levels remains incompletely understood. Collagen fibrils are thought to be primary determinants of whole tendon properties, and therefore we hypothesized that the whole human patellar tendon and its distinct collagen fibrils would display similar mechanical properties. Human patellar tendons ( n = 5) were mechanically tested in vivo by ultrasonography. Biopsies were obtained from each tendon, and individual collagen fibrils were dissected and tested mechanically by atomic force microscopy. The Young's modulus was 2.0 ± 0.5 GPa, and the toe region reached 3.3 ± 1.9% strain in whole patellar tendons. Based on dry cross-sectional area, the Young's modulus of isolated collagen fibrils was 2.8 ± 0.3 GPa, and the toe region reached 0.86 ± 0.08% strain. The measured fibril modulus was insufficient to account for the modulus of the tendon in vivo when fibril content in the tendon was accounted for. Thus, our original hypothesis was not supported, although the in vitro fibril modulus corresponded well with reported in vitro tendon values. This correspondence together with the fibril modulus not being greater than that of tendon supports that fibrillar rather than interfibrillar properties govern the subfailure tendon response, making the fibrillar level a meaningful target of intervention. The lower modulus found in vitro suggests a possible adverse effect of removing the tissue from its natural environment. In addition to the primary work comparing the two hierarchical levels, we also verified the existence of viscoelastic behavior in isolated human collagen fibrils.


2020 ◽  
Vol 22 (1) ◽  
pp. 233
Author(s):  
Eunkuk Park ◽  
Chang Gun Lee ◽  
Eunguk Lim ◽  
Seokjin Hwang ◽  
Seung Hee Yun ◽  
...  

Osteoporosis is a common disease caused by an imbalance of processes between bone resorption by osteoclasts and bone formation by osteoblasts in postmenopausal women. The roots of Gentiana lutea L. (GL) are reported to have beneficial effects on various human diseases related to liver functions and gastrointestinal motility, as well as on arthritis. Here, we fractionated and isolated bioactive constituent(s) responsible for anti-osteoporotic effects of GL root extract. A single phytochemical compound, loganic acid, was identified as a candidate osteoprotective agent. Its anti-osteoporotic effects were examined in vitro and in vivo. Treatment with loganic acid significantly increased osteoblastic differentiation in preosteoblast MC3T3-E1 cells by promoting alkaline phosphatase activity and increasing mRNA expression levels of bone metabolic markers such as Alpl, Bglap, and Sp7. However, loganic acid inhibited osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. For in vivo experiments, the effect of loganic acid on ovariectomized (OVX) mice was examined for 12 weeks. Loganic acid prevented OVX-induced bone mineral density loss and improved bone structural properties in osteoporotic model mice. These results suggest that loganic acid may be a potential therapeutic candidate for treatment of osteoporosis.


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