scholarly journals Characterization and in vitro assessment of three-dimensional extrusion Mg-Sr codoped SiO2-complexed porous microhydroxyapatite whisker scaffolds for biomedical engineering

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Chengyong Li ◽  
Tingting Yan ◽  
Zhenkai Lou ◽  
Zhimin Jiang ◽  
Zhi Shi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Proliferation ◽  
Pore Size ◽  
Osteogenic Differentiation ◽  
Bone Repair ◽  
Porous Scaffold ◽  
Porous Scaffolds ◽  
Sprague Dawley ◽  
Active Elements

Abstract Background Large bone defects have always been a great challenge for orthopedic surgeons. The use of a good bone substitute obtained by bone tissue engineering (BTE) may be an effective treatment method. Artificial hydroxyapatite, a commonly used bone defect filler, is the main inorganic component of bones. Because of its high brittleness, fragility, and lack of osteogenic active elements, its application is limited. Therefore, its fragility should be reduced, its osteogenic activity should be improved, and a more suitable scaffold should be constructed. Methods In this study, a microhydroxyapatite whisker (mHAw) was developed, which was doped with the essential trace active elements Mg2+ and Sr2+ through a low-temperature sintering technique. After being formulated into a slurry, a bionic porous scaffold was manufactured by extrusion molding and freeze drying, and then SiO2 was used to improve the mechanical properties of the scaffold. The hydrophilicity, pore size, surface morphology, surface roughness, mechanical properties, and release rate of the osteogenic elements of the prepared scaffold were detected and analyzed. In in vitro experiments, Sprague–Dawley (SD) rat bone marrow mesenchymal stem cells (rBMSCs) were cultured on the scaffold to evaluate cytotoxicity, cell proliferation, spreading, and osteogenic differentiation. Results Four types of scaffolds were obtained: mHAw-SiO2 (SHA), Mg-doped mHAw-SiO2 (SMHA), Sr-doped mHAw-SiO2 (SSHA), and Mg-Sr codoped mHAw-SiO2 (SMSHA). SHA was the most hydrophilic (WCA 5°), while SMHA was the least (WCA 8°); SMHA had the smallest pore size (247.40 ± 23.66 μm), while SSHA had the largest (286.20 ± 19.04 μm); SHA had the smallest Young's modulus (122.43 ± 28.79 MPa), while SSHA had the largest (188.44 ± 47.89 MPa); and SHA had the smallest compressive strength (1.72 ± 0.29 MPa), while SMHA had the largest (2.47 ± 0.25 MPa). The osteogenic active elements Si, Mg, and Sr were evenly distributed and could be sustainably released from the scaffolds. None of the scaffolds had cytotoxicity. SMSHA had the highest supporting cell proliferation and spreading rate, and its ability to promote osteogenic differentiation of rBMSCs was also the strongest. Conclusions These composite porous scaffolds not only have acceptable physical and chemical properties suitable for BTE but also have higher osteogenic bioactivity and can possibly serve as potential bone repair materials.

IN VITRO EXPERIMENTS ON LASER SINTERED POROUS PCL SCAFFOLDS WITH POLYMER HYDROGEL FOR BONE REPAIR

2011 ◽  
Vol 11 (05) ◽  
pp. 983-992 ◽  
Author(s):  
MING-YIH LEE ◽  
SI-WEN LIU ◽  
JYH-PING CHEN ◽  
HAN-TSUNG LIAO ◽  
WEN-WEI TSAI ◽  
...  
Keyword(s):  
Pore Size ◽  
Bone Repair ◽  
In Vitro Study ◽  
Experimental Results ◽  
Porous Scaffolds ◽  
Immersion Method ◽  
Titration Method ◽  
Polymer Hydrogel ◽  
Loading Methods

Bone defects caused by tumors, diseased infection, trauma or abnormal bone development create a lot of serious health problems. Tissue engineering aims to fabricate tissues or organs using patients' cells for repairing the damaged tissues or organs in clinic. The aim of this study was to design and fabricate polycaprolactone (PCL) scaffolds using the inhouse-built selective laser sintering (SLS) rapid prototyping (RP) machine and combining with polymer hydrogel for in vitro study for bone repair. In this study, three configurations of scaffolds structure (0/45/0/45°, 0/90/0/90°, and 0/45/90/135° patterns) were designed and produced. The compressive modulus, porosity and pore size of porous scaffolds were first determined. In addition, polymer hydrogel was combined with PCL scaffolds with three loading methods (i.e., immersion method, injection method and titration method) to enhance scaffolds surface hydrophilicity for cell proliferation. Mesenchymal stem cells from New Zealand White rabbits were loaded on PCL scaffolds and induced to osteoblasts in vitro. Bone formation was determined by MTS assays, von Kossa stains and ALP activities. The experimental results showed the compressive moduli of scaffolds with 0/45/0/45°, 0/90/0/90°, and 0/45/90/135° patterns was 2 MPa, 3.4 MPa, and 3.75 MPa, respectively. The porosity of scaffolds was 72%, 76%, and 83%, respectively. The ranges of pore size of scaffolds were 350–400 μm, 400–500 μm, and 350–400 μm, respectively. By comparing three kinds of polymer hydrogel loading methods, titration method had the best result. The in vitro experimental results revealed that OD values of MTS tests and ALP activities increased from day 7 to day 21 and von Kossa stain revealed dark brown mineralized tissue, indicating cells could proliferate and differentiate in polymer hydrogel and scaffolds.

scholarly journals Analysis of Mechanical Properties and Permeability of Trabecular-Like Porous Scaffold by Additive Manufacturing

2021 ◽  
Vol 9 ◽  
Author(s):  
Long Chao ◽  
Chen Jiao ◽  
Huixin Liang ◽  
Deqiao Xie ◽  
Lida Shen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Repair ◽  
Bone Cells ◽  
Porous Scaffold ◽  
Bone Ingrowth ◽  
Voronoi Tessellation ◽  
Stress Shielding ◽  
Porous Scaffolds ◽  
Porous Structures ◽  
Element Analysis

Human bone cells live in a complex environment, and the biomimetic design of porous structures attached to implants is in high demand. Porous structures based on Voronoi tessellation with biomimetic potential are gradually used in bone repair scaffolds. In this study, the mechanical properties and permeability of trabecular-like porous scaffolds with different porosity levels and average apertures were analyzed. The mechanical properties of bone-implant scaffolds were evaluated using finite element analysis and a mechanical compression experiment, and the permeability was studied by computational fluid dynamics. Finally, the attachment of cells was observed by confocal fluorescence microscope. The results show that the performance of porous structures can be controlled by the initial design of the microstructure and tissue morphology. A good structural design can accurately match the performance of the natural bone. The study of mechanical properties and permeability of the porous structure can help address several problems, including stress shielding and bone ingrowth in existing biomimetic bone structures, and will also promotes cell adhesion, migration, and eventual new bone attachment.

scholarly journals Additively Manufactured Continuous Cell-Size Gradient Porous Scaffolds: Pore Characteristics, Mechanical Properties and Biological Responses In Vitro

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2589 ◽  
Author(s):  
Fei Liu ◽  
Qichun Ran ◽  
Miao Zhao ◽  
Tao Zhang ◽  
David Z. Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Pore Size ◽  
Cell Size ◽  
Porous Scaffolds ◽  
Ct Reconstruction ◽  
Pore Characteristics ◽  
Growth Environment ◽  
Size Gradient

Porous scaffolds with graded open porosity combining a morphology similar to that of bone with mechanical and biological properties are becoming an attractive candidate for bone grafts. In this work, scaffolds with a continuous cell-size gradient were studied from the aspects of pore properties, mechanical properties and bio-functional properties. Using a mathematical method named triply periodic minimal surfaces (TPMS), uniform and graded scaffolds with Gyroid and Diamond units were manufactured by selective laser melting (SLM) with Ti-6Al-4V, followed by micro-computer tomography (CT) reconstruction, mechanical testing and in vitro evaluation. It was found that gradient scaffolds were preferably replicated by SLM with continuous graded changes in surface area and pore size, but their pore size should be designed to be ≥ 450 μm to ensure good interconnectivity. Both the Gyroid and Diamond structures have superior strength compared to cancellous bones, and their elastic modulus is comparable to the bones. In comparison, Gyroid exhibits better performances than Diamond in terms of the elastic modulus, ultimate strength and ductility. In vitro cell culture experiments show that the gradients provide an ideal growth environment for osteoblast growth in which cells survive well and distribute uniformly due to biocompatibility of the Ti-6Al-4V material, interconnectivity and suitable pore size.

scholarly journals Fabrication and In Vitro Evaluation of 3D Printed Porous Polyetherimide Scaffolds for Bone Tissue Engineering

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiongfeng Tang ◽  
Yanguo Qin ◽  
Xinyu Xu ◽  
Deming Guo ◽  
Wenli Ye ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Cell Proliferation ◽  
Cell Adhesion ◽  
3D Printing ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Porous Scaffold ◽  
3D Printed

For bone tissue engineering, the porous scaffold should provide a biocompatible environment for cell adhesion, proliferation, and differentiation and match the mechanical properties of native bone tissue. In this work, we fabricated porous polyetherimide (PEI) scaffolds using a three-dimensional (3D) printing system, and the pore size was set as 800 μm. The morphology of 3D PEI scaffolds was characterized by the scanning electron microscope. To investigate the mechanical properties of the 3D PEI scaffold, the compressive mechanical test was performed via an electronic universal testing system. For the in vitro cell experiment, bone marrow stromal cells (BMSCs) were cultured on the surface of the 3D PEI scaffold and PEI slice, and cytotoxicity, cell adhesion, and cell proliferation were detected to verify their biocompatibility. Besides, the alkaline phosphatase staining and Alizarin Red staining were performed on the BMSCs of different samples to evaluate the osteogenic differentiation. Through these studies, we found that the 3D PEI scaffold showed an interconnected porous structure, which was consistent with the design. The elastic modulus of the 3D PEI scaffold (941.33 ± 65.26 MPa) falls in the range of modulus for the native cancellous bone. Moreover, the cell proliferation and morphology on the 3D PEI scaffold were better than those on the PEI slice, which revealed that the porous scaffold has good biocompatibility and that no toxic substances were produced during the progress of high-temperature 3D printing. The osteogenic differentiation level of the 3D PEI scaffold and PEI slice was equal and ordinary. All of these results suggest the 3D printed PEI scaffold would be a potential strategy for bone tissue engineering.

scholarly journals Characterization and In Vitro Assessment Of Three-Dimensional Extrusion Mg-Sr Codoped SiO2-Complexed Porous Micro-Hydroxyapatite Whisker Scaffolds For Bone Tissue Engineering

2021 ◽  
Author(s):  
Chengyong Li ◽  
Tingting Yan ◽  
Zhenkai Lou ◽  
Zhimin Jiang ◽  
Zhi Shi ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Bone Repair ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Treatment Method ◽  
Porous Scaffolds ◽  
Active Elements

Abstract Background Orthopedics has made great progress with the development of medical treatment; however, large bone defects are still great challenges for orthopedic surgeons. A good bone substitute that can be obtained through bone tissue engineering may be an effective treatment method. Artificial hydroxyapatite is the main inorganic component of bones, but its applications are limited due to its fragility and lack of bone-active elements. Therefore, it is necessary to reduce its fragility and improve its biological activity. Methods In this study, we developed micro-hydroxyapatite whiskers (mHAws), which were doped with the essential trace active elements Mg2+ and Sr2+ through a low-temperature sintering technique, used silica complexes to improve the mechanical properties, and then manufactured the bionic porous scaffolds by extrusion molding and freeze-drying. Results Four types of scaffolds were obtained: mHAw-SiO2, Mg-doped mHAw-SiO2, Sr-doped mHAw-SiO2 and Mg-Sr-codoped mHAw-SiO2. These composite porous scaffolds have been suggested to have a sufficiently porous morphology with appropriate mechanical strength, are noncytotoxic, are able to support cell proliferation and spreading, and, more importantly, can promote the osteogenic differentiation of rBMSCs. Conclusion Therefore, these doped scaffolds not only have physical and chemical properties suitable for bone tissue engineering, but also have higher osteogenic bioactivity, and can be possibly serve as potential bone repair material.

On the Bio-Mechanical Properties of a Dual-Porous Osteochondral Scaffold

2008 ◽  
Author(s):  
Hajar Sharif ◽  
Yaser Shanjani ◽  
Mihaela Vlasea ◽  
Ehsan Toyserkani
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Porous Scaffold ◽  
Element Model ◽  
Homogeneous Distribution ◽  
Porous Scaffolds ◽  
Osteochondral Scaffold ◽  
Apparent Stiffness

This work is concerned with the finite element modeling of a dual-porous scaffold including both fine and coarse pores. The layer with coarse pores is suitable for bone in vivo ingrowth and the finer pore layer is appropriate for in vitro cartilage culturing. Such scaffolds can be extensively used for repairing of osteochondral defects. The bio-mechanical properties of the proposed scaffold, including apparent stiffness and strain-based capability of the cell ingrowth, are identified using a 3D Finite Element Model. Moreover, to study the effect of the second layer on the strength of the whole scaffold, the stiffness of the dual and single-porous scaffolds was compared. The result of this study shows that the stiffness decreases by adding the second layer to a single-porous scaffold. Additionally, principal strain histograms of the single and the dual-porous scaffolds are compared to assess the effect of added layer on the capability for cell ingrowth stimulation of the whole structure. According to the results, the dual-porous scaffold provides more homogeneous distribution but a smaller amount of micro-strains which may cause different cell-growth behavior.

Characterization and Cell Response of Novel Hydroxyapatite/Glyceride-Based Polyurethane Porous Scaffold

2013 ◽  
Vol 761 ◽  
pp. 141-144 ◽  
Author(s):  
Jing Jing Du ◽  
Yi Zuo ◽  
Qin Zou ◽  
Yu Bao Li
Keyword(s):  
Mtt Assay ◽  
Cell Response ◽  
Bone Repair ◽  
Porous Scaffold ◽  
Biological Properties ◽  
Porous Scaffolds ◽  
Polymer Scaffolds ◽  
Support Cell ◽  
Cell Adhesion And Proliferation

The glycerides of castor oil (GCO) were copolymerized with isophorone diisocyanate (IPDI) to generate glyceride-based polyurethane (GCPU), meanwile blending with hydroxyapatite (HA) powder to fabricate porous composite scaffolds. The effect of HA content on mechanical properties of the resulting polymer scaffolds and the in vitro cell response of HA/GCPU scaffolds were investigated, by use of mechanical testing, FTIR, SEM and MTT assay. The results showed that the compressive strength increased with HA content, and the HA/GCPU scaffold with 40 wt% HA reached about 4.6 MPa, much higher than the scaffold without HA (only 605 kPa). The SEM observation, live-dead staining assay and MTT assay demonstrated the excellent biological properties of HA/GCPU scaffolds, which support cell adhesion and proliferation. This novel class of HA/GCPU porous scaffolds have prospect and advantage for bone repair and regeneration.

scholarly journals Development of Biopolymeric Hybrid Scaffold-Based on AAc/GO/nHAp/TiO2 Nanocomposite for Bone Tissue Engineering: In-Vitro Analysis

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1319
Author(s):  
Muhammad Umar Aslam Khan ◽  
Wafa Shamsan Al-Arjan ◽  
Mona Saad Binkadem ◽  
Hassan Mehboob ◽  
Adnan Haider ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Guar Gum ◽  
Porous Scaffolds ◽  
Vitro Assay ◽  
Vitro Analysis ◽  
Nanocomposite Scaffolds

Bone tissue engineering is an advanced field for treatment of fractured bones to restore/regulate biological functions. Biopolymeric/bioceramic-based hybrid nanocomposite scaffolds are potential biomaterials for bone tissue because of biodegradable and biocompatible characteristics. We report synthesis of nanocomposite based on acrylic acid (AAc)/guar gum (GG), nano-hydroxyapatite (HAp NPs), titanium nanoparticles (TiO2 NPs), and optimum graphene oxide (GO) amount via free radical polymerization method. Porous scaffolds were fabricated through freeze-drying technique and coated with silver sulphadiazine. Different techniques were used to investigate functional group, crystal structural properties, morphology/elemental properties, porosity, and mechanical properties of fabricated scaffolds. Results show that increasing amount of TiO2 in combination with optimized GO has improved physicochemical and microstructural properties, mechanical properties (compressive strength (2.96 to 13.31 MPa) and Young’s modulus (39.56 to 300.81 MPa)), and porous properties (pore size (256.11 to 107.42 μm) and porosity (79.97 to 44.32%)). After 150 min, silver sulfadiazine release was found to be ~94.1%. In vitro assay of scaffolds also exhibited promising results against mouse pre-osteoblast (MC3T3-E1) cell lines. Hence, these fabricated scaffolds would be potential biomaterials for bone tissue engineering in biomedical engineering.

scholarly journals Zn-Containing Membranes for Guided Bone Regeneration in Dentistry

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1797
Author(s):  
Manuel Toledano ◽  
Marta Vallecillo-Rivas ◽  
María T. Osorio ◽  
Esther Muñoz-Soto ◽  
Manuel Toledano-Osorio ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Regeneration ◽  
Bone Healing ◽  
Bone Repair ◽  
Complex Modulus ◽  
Bacterial Colonization ◽  
Guided Bone Regeneration ◽  
M2 Macrophage

Barrier membranes are employed in guided bone regeneration (GBR) to facilitate bone in-growth. A bioactive and biomimetic Zn-doped membrane with the ability to participate in bone healing and regeneration is necessary. The aim of the present study is to state the effect of doping the membranes for GBR with zinc compounds in the improvement of bone regeneration. A literature search was conducted using electronic databases, such as PubMed, MEDLINE, DIMDI, Embase, Scopus and Web of Science. A narrative exploratory review was undertaken, focusing on the antibacterial effects, physicochemical and biological properties of Zn-loaded membranes. Bioactivity, bone formation and cytotoxicity were analyzed. Microstructure and mechanical properties of these membranes were also determined. Zn-doped membranes have inhibited in vivo and in vitro bacterial colonization. Zn-alloy and Zn-doped membranes attained good biocompatibility and were found to be non-toxic to cells. The Zn-doped matrices showed feasible mechanical properties, such as flexibility, strength, complex modulus and tan delta. Zn incorporation in polymeric membranes provided the highest regenerative efficiency for bone healing in experimental animals, potentiating osteogenesis, angiogenesis, biological activity and a balanced remodeling. Zn-loaded membranes doped with SiO2 nanoparticles have performed as bioactive modulators provoking an M2 macrophage increase and are a potential biomaterial for promoting bone repair. Zn-doped membranes have promoted pro-healing phenotypes.

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