Novel Micro-CT Based 3-Dimentional Structural Analyses of Porous Biomaterials

A porous structure comprises pores and pore throats with a complex three-dimensional network structure, and many investigators have described the relationship between average pore size and the amount of bone ingrowth. However, the influence of network structure or pore throats for tissue ingrowth has rarely been discussed. Bioactive porous titanium implants with 48% porosity were analyzed using specific algorithms for three-dimensional analysis of interconnectivity based on a micro focus X-ray computed tomography system. In vivo histological analysis was performed using the very same implants implanted into the femoral condyles of male rabbits for 6 weeks. This matching study revealed that more poorly differentiated pores tended to have narrow pore throats, especially in their shorter routes to the outside. Data obtained suggest that this sort of novel analysis is useful for evaluating bone and tissue ingrowth into porous biomaterials.

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A porous bioactive titanium implant for spinal interbody fusion: an experimental study using a canine model

Journal of Neurosurgery Spine ◽

10.3171/spi-07/10/435 ◽

2007 ◽

Vol 7 (4) ◽

pp. 435-443 ◽

Cited By ~ 44

Author(s):

Mitsuru Takemoto ◽

Shunsuke Fujibayashi ◽

Masashi Neo ◽

Kazutaka So ◽

Norihiro Akiyama ◽

...

Keyword(s):

Mechanical Properties ◽

Histological Examination ◽

Interbody Fusion ◽

Average Pore Size ◽

Spinous Process ◽

Fibrous Tissue ◽

Porous Titanium ◽

Titanium Implants ◽

Average Pore ◽

New Generation

Object Porous biomaterials with adequate pore structure and appropriate mechanical properties are expected to provide a new generation of devices for spinal interbody fusion because of their potential to eliminate bone grafting. The purpose of this study was to evaluate the fusion characteristics of porous bioactive titanium implants using a canine anterior interbody fusion model. Methods Porous titanium implants sintered with volatile spacer particles (porosity 50%, average pore size 303 μm, compressive strength 116.3 MPa) were subjected to chemical and thermal treatments that give a bioactive microporous titania layer on the titanium surface (BT implant). Ten adult female beagle dogs underwent anterior lumbar interbody fusion at L6–7 using either BT implants or nontreated (NT) implants, followed by posterior spinous process wiring and facet screw fixation. Radiographic evaluations were performed at 1, 2, and 3 months postoperatively using X-ray fluoroscopy. Animals were killed 3 months postoperatively, and fusion status was evaluated by manual palpation and histological examination. Results Interbody fusion was confirmed in all five dogs in the BT group and three of five dogs in the NT group. Histological examination demonstrated a large amount of new bone formation with marrowlike tissue in the BT implants and primarily fibrous tissue formation in the NT implants. Conclusions Bioactive treatment effectively enhanced the fusion ability of the porous titanium implants. These findings, coupled with the appropriate mechanical properties in load-bearing conditions, indicate that these porous bioactive titanium implants represent a new generation of biomaterial for spinal interbody fusion.

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Effect of pore size on bone ingrowth into porous titanium implants fabricated by additive manufacturing: An in vivo experiment

Materials Science and Engineering C ◽

10.1016/j.msec.2015.10.069 ◽

2016 ◽

Vol 59 ◽

pp. 690-701 ◽

Cited By ~ 273

Author(s):

Naoya Taniguchi ◽

Shunsuke Fujibayashi ◽

Mitsuru Takemoto ◽

Kiyoyuki Sasaki ◽

Bungo Otsuki ◽

...

Keyword(s):

Additive Manufacturing ◽

Pore Size ◽

Bone Ingrowth ◽

Porous Titanium ◽

Titanium Implants ◽

In Vivo Experiment

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Synthesis of Thermal Polymerizable Alginate-GMA Hydrogel for Cell Encapsulation

Journal of Nanomaterials ◽

10.1155/2015/970619 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 9

Author(s):

Xiaokun Wang ◽

Tong Hao ◽

Jing Qu ◽

Changyong Wang ◽

Haifeng Chen

Keyword(s):

Umbilical Vein ◽

Average Pore Size ◽

Three Dimensional ◽

Cell Encapsulation ◽

Myocardial Repair ◽

Average Pore ◽

Umbilical Vein Endothelial Cells

Alginate is a negative ionic polysaccharide that is found abundantly in nature. Calcium is usually used as a cross-linker for alginate. However, calcium cross-linked alginate is used only forin vitroculture. In the present work, alginate was modified with glycidyl methacrylate (GMA) to produce a thermal polymerizable alginate-GMA (AA-GMA) macromonomer. The molecular structure and methacrylation (%DM) of the macromonomer were determined by1H NMR. After mixing with the correct amount of initiator, the AA-GMA aqueous solution can be polymerized at physiological temperature. The AA-GMA hydrogels exhibited a three-dimensional porous structure with an average pore size ranging from 50 to 200 μm, directly depending on the macromonomer concentration. Biocompatibility of the AA-GMA hydrogel was determined byin vivomuscle injection and cell encapsulation. Muscle injectionin vivoshowed that the AA-GMA solution mixed with initiator could form a hydrogelin situand had a mild inflammatory effect. Human umbilical vein endothelial cells (HUVECs) were encapsulated in the AA-GMA hydrogelsin situat 37°C. Cell viability and proliferation were unaffected by macromonomer concentrations, which suggests that AA-GMA has a potential application in the field of tissue engineering, especially for myocardial repair.

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Evaluation of Peri-Implant Bone Grafting Around Surface-Porous Dental Implants: An In Vivo Study in a Goat Model

Materials ◽

10.3390/ma12213606 ◽

2019 ◽

Vol 12 (21) ◽

pp. 3606 ◽

Cited By ~ 1

Author(s):

Fahad Alshehri ◽

Mohammed Alshehri ◽

Terrence Sumague ◽

Abdurahman Niazy ◽

John Jansen ◽

...

Keyword(s):

Dental Implants ◽

Bone Grafting ◽

Bone Growth ◽

Bone Ingrowth ◽

Titanium Implant ◽

Porous Titanium ◽

Titanium Implants ◽

Biomechanical Assessment ◽

Growth Area

Dental implants with surface-porous designs have been recently developed. Clinically, peri-implant bone grafting is expected to promote early osseointegration and bone ingrowth when applied with surface-porous dental implants in challenging conditions. The aim of this study was to comparatively analyze peri-implant bone healing around solid implants and surface-porous implants with and without peri-implant bone grafting, using biomechanical and histomorphometrical assessment in a goat iliac bone model. A total of 36 implants (4.1 mm wide, 11.5 mm long) divided into three groups, solid titanium implant (STI; n = 12), porous titanium implants (PTI; n = 12) and PTI with peri-implant bone grafting using biphasic calcium phosphate granules (PTI + BCP; n = 12), were placed bilaterally in the iliac crests of six goats. The goats were sacrificed seven weeks post-operatively and then subjected to biomechanical (n = 6 per group) and histomorphometrical (n = 6 per group) assessment. The biomechanical assessment revealed no significant differences between the three types of implants. Although the peri-implant bone-area (PIBA%) measured by histomorphometry (STI: 8.63 ± 3.93%, PTI: 9.89 ± 3.69%, PTI + BCP: 9.28 ± 2.61%) was similar for the three experimental groups, the percentage of new bone growth area (BGA%) inside the porous implant portion was significantly higher (p < 0.05) in the PTI group (10.67 ± 4.61%) compared to the PTI + BCP group (6.50 ± 6.53%). These data demonstrate that peri-implant bone grafting around surface-porous dental implants does not significantly accelerate early osseointegration and bone ingrowth.

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The combination of multi-functional ingredients-loaded hydrogels and three-dimensional printed porous titanium alloys for infective bone defect treatment

Journal of Tissue Engineering ◽

10.1177/2041731420965797 ◽

2020 ◽

Vol 11 ◽

pp. 204173142096579

Author(s):

Shichong Qiao ◽

Dongle Wu ◽

Zuhao Li ◽

Yu Zhu ◽

Fei Zhan ◽

...

Keyword(s):

Bone Regeneration ◽

Bone Ingrowth ◽

Three Dimensional ◽

Supramolecular Assembly ◽

Porous Titanium ◽

Novel Therapy ◽

In Vivo Experiments ◽

Marrow Mesenchymal Stem Cells

Biomaterial with the dual-functions of bone regeneration and antibacterial is a novel therapy for infective bone defects. Three-dimensional (3D)-printed porous titanium (pTi) benefits bone ingrowth, but its microporous structure conducive to bacteria reproduction. Herein, a multifunctional hydrogel was prepared from dynamic supramolecular assembly of sodium tetraborate (Na2B4O7), polyvinyl alcohol (PVA), silver nanoparticles (AgNPs) and tetraethyl orthosilicate (TEOS), and composited with pTi as an implant system. The pTi scaffolds have ideal pore size and porosity matching with bone, while the supramolecular hydrogel endows pTi scaffolds with antibacterial and biological activity. In vitro assessments indicated the 3D composite implant was biocompatible, promoted bone marrow mesenchymal stem cells (BMSCs) proliferation and osteogenic differentiation, and inhibited bacteria, simultaneously. In vivo experiments further demonstrated that the implant showed effective antibacterial ability while promoting bone regeneration. Besides distal femur defect, the innovative scaffolds may also serve as an ideal biomaterial (e.g. dental implants) for other contaminated defects.

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Porosity Characterization of Sintered Titanium Scaffolds for Surgical Implants

Materials Science Forum ◽

10.4028/www.scientific.net/msf.591-593.36 ◽

2008 ◽

Vol 591-593 ◽

pp. 36-41 ◽

Cited By ~ 4

Author(s):

Marize Varella de Oliveira ◽

Anderson Camargo Moreira ◽

Luiz Carlos Pereira ◽

Waléria Silva de Medeiros ◽

Carlos R. Appoloni

Keyword(s):

Gamma Ray ◽

Bone Ingrowth ◽

Three Dimensional ◽

Porous Titanium ◽

Metallographic Analysis ◽

Surgical Implants ◽

Biomaterial Scaffolds ◽

The One ◽

Implant Coatings

Porosity and pore size are critical features for biomaterial scaffolds as they play an essential role in bone formation and bone ingrowth in vivo. Therefore, techniques for scaffolds evaluation are of great importance for their design and processing. Porous titanium has been used for grafts and implant coatings as it allows the mechanical interlocking of the pores and bone. In this study, porous titanium samples were manufactured by powder metallurgy. The porosity quantification was assessed by optical quantitative metallographic analysis, and non-destructive gamma-ray transmission and X-ray microtomography techniques, in order to compare their efficacy for porosity evaluation. Pore morphology and surface topography were characterized via scanning electron microscopy. These techniques have demonstrated to be suitable for titanium scaffolds evaluation, and micro-CT was the one that allowed the three-dimensional porosity assessment.

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Titanium oral implants: surface characteristics, interface biology and clinical outcome

Journal of The Royal Society Interface ◽

10.1098/rsif.2010.0118.focus ◽

2010 ◽

Vol 7 (suppl_5) ◽

Cited By ~ 128

Author(s):

Anders Palmquist ◽

Omar M. Omar ◽

Marco Esposito ◽

Jukka Lausmaa ◽

Peter Thomsen

Keyword(s):

Surface Properties ◽

Cellular Response ◽

Randomized Clinical Trials ◽

Three Dimensional ◽

Cell Communication ◽

Surface Characteristics ◽

Titanium Implants ◽

Material Surface ◽

Oral Implants

Bone-anchored titanium implants have revolutionized oral healthcare. Surface properties of oral titanium implants play decisive roles for molecular interactions, cellular response and bone regeneration. Nevertheless, the role of specific surface properties, such as chemical and phase composition and nanoscale features, for the biological in vivo performance remains to be established. Partly, this is due to limited transfer of state-of-the-art preparation techniques to complex three-dimensional geometries, analytical tools and access to minute, intact interfacial layers. As judged by the available results of a few randomized clinical trials, there is no evidence that any particular type of oral implant has superior long-term success. Important insights into the recruitment of mesenchymal stem cells, cell–cell communication at the interface and high-resolution imaging of the interface between the surface oxide and the biological host are prerequisites for the understanding of the mechanisms of osseointegration. Strategies for development of the next generation of material surface modifications for compromised tissue are likely to include time and functionally programmed properties, pharmacological modulation and incorporation of cellular components.

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Li4Mn5O12 Lithium Ion Sieve Preparation and Adsorption Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1004-1005.670 ◽

2014 ◽

Vol 1004-1005 ◽

pp. 670-674 ◽

Cited By ~ 1

Author(s):

Dian Quan Dong ◽

Hong Bo Dai ◽

Jian Guo Zheng

Keyword(s):

High Selectivity ◽

Colloidal Crystal ◽

Average Pore Size ◽

Three Dimensional ◽

Lithium Ion ◽

Precursor Solution ◽

Exchange Capacity ◽

Average Pore ◽

Exchange Performance ◽

Roasting Condition

Polystyrene microspheres with 120nm diameter were synthesized by emulsion polymerization and three-dimensionally ordered colloidal crystal templates were obtained by centrifugal sedimentation.Three dimensionally ordered nanopore (3DON) manganese oxide lithium ion-sieve was prepared after filtration, two heated roasting and acid modified by using precursor solution filling the colloidal crystal templates, which was prepared by Lithium salt, manganese salt and citric acid. SEM, XRD, and saturated exchange capacity test were used to characterize the roasting condition, appearance, structure, and ion exchange performance of the oxide. The results showed that, the optimum roasting condition of preparing lithium ion-sieve precursors were found as follows: heating rate at 2°C/min, 300 °C roasting 4h and 800 °C roasting 8h, The 3DON Li4Mn5O12lithium ion sieve precursor has the shape of three-dimensional cross-linked connected into the network structure. Li4Mn5O12was regularly arranged and the hole wall was integrity,average pore size of approximately 90nm.3DON Li4Mn5O12 showed good stability for acid and the retrofit of lithium ion-sieve showed a high selectivity for Li+. The saturated exchange capacity of Li+is 51.98mgLi+/g.

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Alginate/Gelatin Hydrogels Reinforced with TiO2 and β-TCP Fabricated by Microextrusion-based Printing for Tissue Regeneration

Polymers ◽

10.3390/polym11030457 ◽

2019 ◽

Vol 11 (3) ◽

pp. 457 ◽

Cited By ~ 9

Author(s):

Rodrigo Urruela-Barrios ◽

Erick Ramírez-Cedillo ◽

A. Díaz de León ◽

Alejandro Alvarez ◽

Wendy Ortega-Lara

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Tissue Regeneration ◽

Average Pore Size ◽

Three Dimensional ◽

Engineering Applications ◽

Average Pore ◽

Viscous Deformation ◽

Freeze Dried ◽

3D Printed

Three-dimensional (3D) printing technologies have become an attractive manufacturing process to fabricate scaffolds in tissue engineering. Recent research has focused on the fabrication of alginate complex shaped structures that closely mimic biological organs or tissues. Alginates can be effectively manufactured into porous three-dimensional networks for tissue engineering applications. However, the structure, mechanical properties, and shape fidelity of 3D-printed alginate hydrogels used for preparing tissue-engineered scaffolds is difficult to control. In this work, the use of alginate/gelatin hydrogels reinforced with TiO2 and β-tricalcium phosphate was studied to tailor the mechanical properties of 3D-printed hydrogels. The hydrogels reinforced with TiO2 and β-TCP showed enhanced mechanical properties up to 20 MPa of elastic modulus. Furthermore, the pores of the crosslinked printed structures were measured with an average pore size of 200 μm. Additionally, it was found that as more layers of the design were printed, there was an increase of the line width of the bottom layers due to its viscous deformation. Shrinkage of the design when the hydrogel is crosslinked and freeze dried was also measured and found to be up to 27% from the printed design. Overall, the proposed approach enabled fabrication of 3D-printed alginate scaffolds with adequate physical properties for tissue engineering applications.

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