scholarly journals Design and analysis of three-dimensional printing of a porous titanium scaffold

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jiajie Yang ◽  
Yaqiang Li ◽  
Xiaojian Shi ◽  
Meihua Shen ◽  
Kaibing Shi ◽  
...  
Keyword(s):  
Compressive Strength ◽  
3D Printing ◽  
Pore Size ◽  
Three Dimensional ◽  
Structural Models ◽  
Porous Titanium ◽  
Knee Joints ◽  
Regular Tetrahedron ◽  
Diamond Structure ◽  
Pore Morphology

Abstract Objective Mechanic strength, pore morphology and size are key factors for the three-dimensional (3D) printing of porous titanium scaffolds, therefore, developing optimal structure for the 3D printed titanium scaffold to fill bone defects in knee joints is instructive and important. Methods Structural models of titanium scaffolds with fifteen different pore unit were designed with 3D printing computer software; five different scaffold shapes were designed: imitation diamond-60°, imitation diamond-90°, imitation diamond-120°, regular tetrahedron and regular hexahedron. Each structural shape was evaluated with three pore sizes (400, 600 and 800 μm), and fifteen types of cylindrical models (size: 20 mm; height: 20 mm). Autodesk Inventor software was used to determine the strength and safety of the models by simulating simple strength acting on the knee joints. We analyzed the data and found suitable models for the design of 3D printing of porous titanium scaffolds. Results Fifteen different types of pore unit structural models were evaluated under positive pressure and lateral pressure; the compressive strength reduced when the pore size increased. Under torsional pressure, the strengths of the imitation diamond structure were similar when the pore size increased, and the strengths of the regular tetrahedron and regular hexahedron structures reduced when the pore size increased. In each case, the compressive strength of the regular hexahedron structure was highest, that of the regular tetrahedron was second highest, and that of the imitation diamond structure was relatively low. Fifteen types of cylindrical models under a set force were evaluated, and the sequence of comprehensive compressive strength, from strong to weak was: regular hexahedron > regular tetrahedron > imitation diamond-120° > imitation diamond-90° > imitation diamond-60°. The compressive strength of cylinder models was higher when the pore size was smaller. Conclusion The pore size and pore morphology were important factors influencing the compressive strength. The strength of each structure reduced when the pore size (400, 600 and 800 μm) increased. The models of regular hexahedron, regular tetrahedron and imitation diamond-120°appeared to meet the conditions of large pore sizes and high compressive strength.

Design and Analysis of Three-Dimensional Printing of A Porous Titanium Scaffold

2021 ◽  
Author(s):  
Chunxi Yang ◽  
Jiajie Yang ◽  
Xiaojian Shi ◽  
Meihua Shen ◽  
Kaibing Shi ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Pore Diameter ◽  
Three Dimensional ◽  
Structural Models ◽  
Porous Titanium ◽  
Knee Joints ◽  
Positive Pressure ◽  
Regular Tetrahedron ◽  
Diamond Structure ◽  
Structural Shape

Abstract Objective To develop suitable structural designs for the three-dimensional (3-D) printing of a porous titanium scaffold to fill bone defects in knee joints. Pore diameter and mechanic strength are key factors for the 3-D printing of porous titanium scaffolds. Methods Fifteen different pore unit structural models of titanium scaffolds were designed with 3-D printing computer software; five different scaffold shapes were designed: imitation diamond-60°, imitation diamond-90°, imitation diamond-120°, regular tetrahedron and regular hexahedron. Each structural shape was evaluated with three pore diameters 400μm, 600μm and 800μm, and fifteen types of cylindrical models(diameter: 20mm; height: 20mm). Autodesk Inventor software was used determine the strength and safety of the models by simulating simple strength acting on the knee joints. We analyzed the data and found suitable models for 3-D printing of porous titanium scaffolds. Results Fifteen different types of pore unit structural models were evaluated under positive pressure; the compressive strength was lower when the pore diameter(400μm, 600μm and 800μm) was larger, except for the regular tetrahedron structure. Under lateral pressure, the compressive strength was also lower when the pore diameter(400μm, 600μm and 800μm) was larger. Under torsional pressure, the strength of the imitation diamond structure was similar when the pore diameter(400μm, 600μm and 800μm) was larger, and the strengths of the regular tetrahedron and regular hexahedron structures were lower when the pore diameter(400μm, 600μm and 800μm) was larger. In each case, the compressive strength of the regular hexahedron structure was highest, that of the regular tetrahedron was second highest, and that of the imitation diamond structure was relatively low. Fifteen types of cylindrical models under a set force were evaluated, and the sequence of comprehensive compressive strength, from strong to weak was: regular hexahedron> regular tetrahedron> imitation diamond-120°> imitation diamond-90°> imitation diamond-60°. The compressive strength of cylinder models was higher when the pore diameter was smaller. Conclusion The compressive strength differed among titanium scaffolds with different pore structures. The pore diameter and shapes of the pore structure were important factors influencing the compressive strength. The models of regular hexahedron, regular tetrahedron and imitation diamond-120°appeared to meet the conditions of large pore diameters and high compressive strength. The strength of each structure was lower when the pore diameter(400μm, 600μm and 800μm) was larger.

scholarly journals Chitosan/Gelatin/PVA Scaffolds for Beta Pancreatic Cell Culture

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2372
Author(s):  
Yesenia Sánchez-Cardona ◽  
Claudia E. Echeverri-Cuartas ◽  
Marta E. Londoño López ◽  
Natalia Moreno-Castellanos
Keyword(s):  
Compressive Strength ◽  
Cell Viability ◽  
Pore Size ◽  
Three Dimensional ◽  
Ternary Blend ◽  
Ternary Blends ◽  
Binary Blend ◽  
Pancreatic Cell ◽  
Degradation Rates ◽  
Swelling Rate

Chitosan scaffolds based on blending polymers are a common strategy used in tissue engineering. The objective of this study was evaluation the properties of scaffolds based on a ternary blend of chitosan (Chi), gelatin (Ge), and polyvinyl alcohol (PVA) (Chi/Ge/PVA), which were prepared by cycles of freeze-thawing and freeze-drying. It then was used for three-dimensional BRIN-BD11 beta-cells culturing. Weight ratios of Chi/Ge/PVA (1:1:1, 2:2:1, 2:3:1, and 3:2:1) were proposed and porosity, pore size, degradation, swelling rate, compressive strength, and cell viability analyzed. All ternary blend scaffolds structures are highly porous (with a porosity higher than 80%) and interconnected. The pore size distribution varied from 0.6 to 265 μm. Ternary blends scaffolds had controllable degradation rates compared to binary blend scaffolds, and an improved swelling capacity of the samples with increasing chitosan concentration was found. An increase in Young’s modulus and compressive strength was observed with increasing gelatin concentration. The highest compressive strength reached 101.6 Pa. The MTT assay showed that the ternary blends scaffolds P3 and P4 supported cell viability better than the binary blend scaffold. Therefore, these results illustrated that ternary blends scaffolds P3 and P4 could provide a better environment for BRIN-BD11 cell proliferation.

Design and additive manufacturing of porous titanium scaffolds for optimum cell viability in bone tissue engineering

2020 ◽  
pp. 095440542093756
Author(s):  
Bingbing Li ◽  
Bani Davod Hesar ◽  
Yiwen Zhao ◽  
Li Ding
Keyword(s):  
Tissue Engineering ◽  
Cell Viability ◽  
Bone Tissue Engineering ◽  
Pore Size ◽  
Bone Tissue ◽  
Structural Strength ◽  
Three Dimensional ◽  
Porous Titanium ◽  
Nih3t3 Cells ◽  
Pore Sizes

Pore size, external shape, and internal complexity of additively manufactured porous titanium scaffolds are three primary determinants of cell viability and structural strength of scaffolds in bone tissue engineering. To obtain an optimal design with the combination of all three determinants, four scaffolds each with a unique topology (external geometry and internal structure) were designed and varied the pore sizes of each scaffold 3 times. For each topology, scaffolds with pore sizes of 300, 400, and 500 µm were designed. All designed scaffolds were additively manufactured in material Ti6Al4V by the direct metal laser melting machine. Compression test was conducted on the scaffolds to assure meeting minimum compressive strength of human bone. The effects of pore size and topology on the cell viability of the scaffolds were analyzed. The 12 scaffolds were ultrasonically cleaned and seeded with NIH3T3 cells. Each scaffold was seeded with 1 million cells. After 32 days of culturing, the cells were fixed for their three-dimensional architecture preservation and to obtain scanning electron microscope images.

Preparation and Characterization of Ha/Gel/β-TCP Microspheres Composite Porous Scaffold

2018 ◽  
Vol 782 ◽  
pp. 103-115
Author(s):  
Yang Zi Zhao ◽  
You Fa Wang
Keyword(s):  
Tissue Engineering ◽  
Compressive Strength ◽  
Hyaluronic Acid ◽  
Pore Size ◽  
Porous Scaffold ◽  
Three Dimensional ◽  
Swelling Ratio ◽  
Cell Compatibility ◽  
Hydrogel Scaffolds

Being one of the three elements of tissue engineering, three-dimensional porous structure scaffold plays an important role in tissue engineering. As it not only prvovide cells for the life, but also serves as a template to guide tissue regeneration and control of organizational structure and other functions. In this study, hyaluronic acid and gelatin are successfully cross-linked by 1-ethyl- (3-dimethylaminopropyl) -carbodiimide hydrochloride (EDC) , and compound β-TCP microspheres to prepare porous hydrogel scaffolds. The microspheres were analyzed by X-ray diffraction (XRD). The scaffolds were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). At the same time, the compressive strength, swelling ratio, degradation of the scaffold were tested. To assess the in vitro cell compatibility of the scaffolds, mouse L929 fibroblasts were seeded onto scaffolds for cell morphology and cell viability studies. The results showed that the pore size of the porous scaffold can be adjusted by changing the ratio of gelatin to hyaluronic acid (HA), increasing the proportion of hyaluronic acid in a certain range, pore size will be significantly increased. With the increase of the proportion of hyaluronic acid in the scaffold, the swelling ratio and the degradation rate also increased. The compressive strength of the scaffold increased with the increase of the proportion of gelatin. The appropriate ratio of β-TCP can promote cell growth and proliferation.

Design and Fabrication of Customised Scaffold for Femur Bone Using 3D Printing

2013 ◽  
Vol 845 ◽  
pp. 920-924
Author(s):  
V. Iraimudi ◽  
S. Rashia Begum ◽  
G. Arumaikkannu ◽  
R. Narayanan
Keyword(s):  
3D Printing ◽  
Pore Size ◽  
Three Dimensional ◽  
Unit Cell ◽  
Bone Scaffold ◽  
Software Patterns ◽  
3D Cad ◽  
Bone Scaffolds ◽  
Femur Bone ◽  
Scan Data

Additive Manufacturing is a promising field for making three dimensional scaffolds in which parts are fabricated directly from the 3D CAD model. This paper presents, the patients CT scan data of femur bone in DICOM format is exported into MIMICS software to stack 2D scan data into 3D model. Four layers of femur bone were selected for creation of customised femur bone scaffold. Unit cell designs such as double bend curve, S bend curve, U bend curve and steps were designed using SOLIDWORKS software. Basic primitives namely square, hexagon and octagon primitives of pore size 0.6mm, 0.7 mm and 0.8 mm diameter and inter distance 0.7mm, 0.8mm and 0.9 mm are used to design the scaffold structures. In 3matic software, patterns were developed by using the above four unit cells. Then, the four layers of bone and patterns were imported into 3matic to create customised bone scaffolds. The porosities of customised femur bone scaffold were determined using the MIMICS software. It was found that the customised femur bone scaffolds for the unit cell design of U bend curve with square primitives of pore size 0.8mm diameter and inter distance 0.7mm gives higher porosity of 56.58 % compared to other scaffolds. The models were then fabricated using 3D printing technique.

Preparation and Research of Porous KGM/ Collagen II Composite Cartilage Scaffolds

2013 ◽  
Vol 774-776 ◽  
pp. 949-953
Author(s):  
Ming Hua Huang ◽  
Hui Dong ◽  
Di Ru Xu ◽  
Duan Cheng Wang ◽  
Yong Shun Cui ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Pore Size ◽  
Raw Materials ◽  
Average Pore Size ◽  
Crosslinking Agent ◽  
Three Dimensional ◽  
Average Pore ◽  
Blending Method ◽  
Collagen Ii

KGM and Collagen II were selected as the main raw materials and ammonia served as the crosslinking agent to prepare the porous KGM / COLII composite cartilage scaffolds by blending method and freeze-drying method. The porosity, average pore size, compressive strength and water absorption were measured on the basis of the related standard. The scaffolds were characterized by SEM and XRD. The results show that the optimal program of preparing composite cartilage scaffolds is KGM (2g), COLII (1g), freeze temperature (-20 ° C) and ammonia (0.1 ml). The optimal cartilage scaffolds are porous three-dimensional network structures which the porosity is more than 90%; the average pore size is about 200μm; the compressive strength is about 0.75Mpa and the water absorption reaches up to 892%.

Finite Element Simulation of Pore Morphology and Stress Distribution of Porous Titanium

2015 ◽  
Vol 1120-1121 ◽  
pp. 932-936 ◽  
Author(s):  
Chun Yan Wang ◽  
Bo Qiong Li
Keyword(s):  
Stress Distribution ◽  
Pore Size ◽  
Concentration Factor ◽  
Average Pore Size ◽  
Porous Titanium ◽  
Pore Morphology ◽  
Ansys Software ◽  
Average Pore ◽  
Porous Ti ◽  
Element Simulation

Porous Ti with an average pore size of 200-400 μm and porosity in the range of 25-50% has been manufactured using polymethyl methacrylate (PMMA) powders as spacer particles. The stress distribution of porous Ti was analyzed by Ansys software. The stress is prone to focusing on the surrounding of connected pore and weak cell. As the porosity and pore size increase, the concentration factor of stress increases due to the lager degree of pore connection and aggregation. Comparing with the ellipsoid pore model, the concentration factor of stress of the porous Ti with spherical pore is lower.

scholarly journals Biomimetic Design for a Dual Concentric Porous Titanium Scaffold with Appropriate Compressive Strength and Cells Affinity

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3316
Author(s):  
Han Lee ◽  
Jiunn-Der Liao ◽  
Yao-Sheng Guo ◽  
Yung-Der Juang
Keyword(s):  
Compressive Strength ◽  
Three Dimensional ◽  
L929 Cell ◽  
Porous Titanium ◽  
Nanomechanical Property ◽  
High Cell ◽  
Sintering Process ◽  
Cell Mortality ◽  
Cell Affinity ◽  
Cp Ti

In repairing or replacing damaged bones, a dual concentric porous titanium scaffold (P-Tix-y) has emerged as a promising bio-mimic design. Herein, various P-Tix-y were made and sintered with relatively dense (x = 10, 20, or 30% porosity) and loose (y = 45, 55, or 65 porosity) structures. Firstly, NaCl was used as the pore-forming additive and followed by a hydrothermal removal method. The compressive strength of the as-formed P-Tix_y and surface morphology, nanomechanical property, and cells’ affinity on the cross-sectioned surface of P-Tix_y (CP-Tix_y) were then characterized. The results demonstrate that the compressive strength of P-Ti10_45, P-Ti20_45, or P-Ti20_55 exhibits a relatively mild decline (e.g., in the range of 181 and 97 MPa, higher than the required value of 70 MPa) and suitable porosities for the intended structure. Nano-hardness on the solid surface of CP-Tix_y shows roughly consistent with that of CP-Ti (i.e., ~8.78 GPa), thus, the porous structure of CP-Tix_y remains mostly unaffected by the addition of NaCl and subsequent sintering process. Most of the surfaces of CP-Tix_y exhibit high fibroblast (L929) cell affinity with low cell mortality. Notably, in the hFOB 1.19 cell adhesion and proliferation test, CP-Ti20_55 and CP-Ti20_65 reveal high cell viability, most probably relating with the assembly of dual porosities with interconnected pores. Overall, the sample P-Ti20_55 provides a relatively load-bearable design with high cell affinity and is thus promising as a three-dimensional bio-scaffold.

scholarly journals Investigating Approaches for Three-Dimensional Printing of Hydroxyapatite Scaffolds for Bone Regeneration

2014 ◽  
Vol 631 ◽  
pp. 306-311 ◽  
Author(s):  
Zuo Xin Zhou ◽  
Fraser Buchanan ◽  
Alex Lennon ◽  
Nicholas Dunne
Keyword(s):  
Compressive Strength ◽  
3D Printing ◽  
Polyvinyl Alcohol ◽  
Bone Regeneration ◽  
Three Dimensional ◽  
High Viscosity ◽  
Three Dimensional Printing ◽  
3D Printing Technology ◽  
Printing Quality ◽  
Dimensional Printing

This study investigated the feasibility of manufacturing hydroxyapatite (HA)-based scaffolds using 3D printing technology by incorporating different binding additives, such as maltodextrin and polyvinyl alcohol (PVOH), into the powder formulation. Different grades of PVOH were evaluated in terms of their impact on the printing quality. Results showed that scaffolds with high architectural accuracy in terms of the design and excellent green compressive strength were obtained when the PVOH (high viscosity) was used as the binding additive for HA.

scholarly journals Efficacy evaluation of three-dimensional printing assisted osteotomy guide plate in accurate osteotomy of adolescent cubitus varus deformity

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Yuan-Wei Zhang ◽  
Xin Xiao ◽  
Wen-Cheng Gao ◽  
Yan Xiao ◽  
Su-Li Zhang ◽  
...  
Keyword(s):  
3D Printing ◽  
Blood Loss ◽  
Three Dimensional ◽  
Operation Time ◽  
Varus Deformity ◽  
Conventional Group ◽  
Intraoperative Blood Loss ◽  
Cubitus Varus ◽  
Guide Plate ◽  
Significant Difference

Abstract Background This present study is aimed to retrospectively assess the efficacy of three-dimensional (3D) printing assisted osteotomy guide plate in accurate osteotomy of adolescent cubitus varus deformity. Material and methods Twenty-five patients (15 males and 10 females) with the cubitus varus deformity from June 2014 to December 2017 were included in this study and were enrolled into the conventional group (n = 11) and 3D printing group (n = 14) according to the different surgical approaches. The operation time, intraoperative blood loss, osteotomy degrees, osteotomy end union time, and postoperative complications between the two groups were observed and recorded. Results Compared with the conventional group, the 3D printing group has the advantages of shorter operation time, less intraoperative blood loss, higher rate of excellent correction, and higher rate of the parents’ excellent satisfaction with appearance after deformity correction (P < 0.001, P < 0.001, P = 0.019, P = 0.023). Nevertheless, no significant difference was presented in postoperative carrying angle of the deformed side and total complication rate between the two groups (P = 0.626, P = 0.371). Conclusions The operation assisted by 3D printing osteotomy guide plate to correct the adolescent cubitus varus deformity is feasible and effective, which might be an optional approach to promote the accurate osteotomy and optimize the efficacy.

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