scholarly journals Intrinsic Osteoinductivity of Porous Titanium Scaffold for Bone Tissue Engineering

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Maryam Tamaddon ◽  
Sorousheh Samizadeh ◽  
Ling Wang ◽  
Gordon Blunn ◽  
Chaozong Liu

Large bone defects and nonunions are serious complications that are caused by extensive trauma or tumour. As traditional therapies fail to repair these critical-sized defects, tissue engineering scaffolds can be used to regenerate the damaged tissue. Highly porous titanium scaffolds, produced by selective laser sintering with mechanical properties in range of trabecular bone (compressive strength 35 MPa and modulus 73 MPa), can be used in these orthopaedic applications, if a stable mechanical fixation is provided. Hydroxyapatite coatings are generally considered essential and/or beneficial for bone formation; however, debonding of the coatings is one of the main concerns. We hypothesised that the titanium scaffolds have an intrinsic potential to induce bone formation without the need for a hydroxyapatite coating. In this paper, titanium scaffolds coated with hydroxyapatite using electrochemical method were fabricated and osteoinductivity of coated and noncoated scaffolds was compared in vitro. Alizarin Red quantification confirmed osteogenesis independent of coating. Bone formation and ingrowth into the titanium scaffolds were evaluated in sheep stifle joints. The examinations after 3 months revealed 70% bone ingrowth into the scaffold confirming its osteoinductive capacity. It is shown that the developed titanium scaffold has an intrinsic capacity for bone formation and is a suitable scaffold for bone tissue engineering.

2018 ◽  
pp. 461-475 ◽  
Author(s):  
Ozan Karaman

The limitation of orthopedic fractures and large bone defects treatments has brought the focus on fabricating bone grafts that could enhance ostegenesis and vascularization in-vitro. Developing biomimetic materials such as mineralized nanofibers that can provide three-dimensional templates of the natural bone extracellular-matrix is one of the most promising alternative for bone regeneration. Understanding the interactions between the structure of the scaffolds and cells and therefore the control cellular pathways are critical for developing functional bone grafts. In order to enhance bone regeneration, the engineered scaffold needs to mimic the characteristics of composite bone ECM. This chapter reviews the fabrication of and fabrication techniques for fabricating biomimetic bone tissue engineering scaffolds. In addition, the chapter covers design criteria for developing the scaffolds and examples of enhanced osteogenic differentiation outcomes by fabricating biomimetic scaffolds.


2016 ◽  
Vol 89 (1) ◽  
pp. 847-853 ◽  
Author(s):  
Zhiyu Liao ◽  
Faris Sinjab ◽  
Amy Nommeots-Nomm ◽  
Julian Jones ◽  
Laura Ruiz-Cantu ◽  
...  

Author(s):  
Masud Rana Md. ◽  
Naznin Akhtar ◽  
Zahid Hasan Md. ◽  
Asaduzzaman S M

Bone tissue engineering with cells and synthetic extracellular matrix represents a new approach for the regeneration of mineralized tissue compared with the transplantation of bone. Hydroxyapatite (HA) and its composite with biopolymer are extensively developed and applied in bone tissue regeneration. The main aim of this study was to fabricate and characterize of HA apatite based biocompatible scaffold for bone tissue engineering. Scaffolds with different ratio of polymers (chitosan & alginate), and fixed amount of synthetic HA were prepared using in situ co precipitation method and mineral to polymer ratio was 1:1 to 1: 2 . A cross linker agent, 2-Hydroxylmethacrylate (HEMA) was added at different percentage (0.5-2%) into the selected composition and irradiated at 5- 25 kGy to optimize the proper mixing of components at the presence of HEMA. Fabricated scaffolds were analyzed to determine porosity, density, biodegradability, morphology and structural properties. Porosity and density of the prepared scaffold were 75 to 92% and 0.21 to 0.42 g/cm3 respectively. However, the swelling ratio of the fabricated scaffolds was ranged from 133 to 197%. Nonetheless, there had a reasonable in-vitro degradation of prepared scaffolds. Flourier transform infrared spectroscopy (FTIR) analysis showed intermolecular interaction between components in the scaffold. Pore size of scaffold was measured by scanning electron microscope and the value was 162-510 μm. It could be proposed that this scaffold fulfills all the main requirements to be considered as a bone substitute for biomedical application in near future.


Author(s):  
Maryam Shadravanan ◽  
Mona Latifi ◽  
Zahra Vojdani ◽  
Tahereh Talaei-Khozani

Background: Hydroxyapatite (HAP), as a common biomaterial in bone tissue engineering, can be fabricated in combination with other osteogenic agents. Pentoxifylline (PTX) is demonstrated to have positive roles in bone defect healing. Since local administration can diminish the systemic side effects of the drug, the objectives of the current in vitro study were to find the effects of PTX on the osteoblast functions for tissue engineering applications. Methods: a HAP scaffold was fabricated by casting the HAP slurry within polyurethane foam. The scaffold was enriched with 5 mg/mL PTX. Alginate (Alg) was used as drug carrier to regulate the PTX releasing rate. MG-63 osteosarcoma cells were cultured on 3D scaffolds and 2D Alg films in the presence or absence of PTX. Results: PTX did not affect the cell viability, attachment and phenotype. Also, the ultrastructure of the scaffolds was not modified by PTX enrichment. Alizarin red S staining showed that PTX has no effect on calcium deposition. Besides, Raman confocal microscopy demonstrated an increase in the organic matrix formation including proline, valine and phenylalanine deposition (represented collagen). Although PTX increased the total protein secretion, it led to a decrease in the alkaline phosphatase activity and vascular endothelial growth factor (VEGF) content. PTX reduced the hydration and degradation rates and it was released mainly at the first 24 hours of incubation. Conclusion: Based on our in vitro study, application of engineered PTX-loaded HAP scaffold in bone regeneration can act on behalf of organic matrix production, but not angiogenesis and mineralization.


2010 ◽  
Vol 7 (suppl_5) ◽  
Author(s):  
Yuelian Liu ◽  
Gang Wu ◽  
Klaas de Groot

The repair of critical-sized bone defects is still challenging in the fields of implantology, maxillofacial surgery and orthopaedics. Current therapies such as autografts and allografts are associated with various limitations. Cytokine-based bone tissue engineering has been attracting increasing attention. Bone-inducing agents have been locally injected to stimulate the native bone-formation activity, but without much success. The reason is that these drugs must be delivered slowly and at a low concentration to be effective. This then mimics the natural method of cytokine release. For this purpose, a suitable vehicle was developed, the so-called biomimetic coating, which can be deposited on metal implants as well as on biomaterials. Materials that are currently used to fill bony defects cannot by themselves trigger bone formation. Therefore, biological functionalization of such materials by the biomimetic method resulted in a novel biomimetic coating onto different biomaterials. Bone morphogenetic protein 2 (BMP-2)-incorporated biomimetic coating can be a solution for a large bone defect repair in the fields of dental implantology, maxillofacial surgery and orthopaedics. Here, we review the performance of the biomimetic coating both in vitro and in vivo .


2005 ◽  
Vol 128 (2) ◽  
pp. 531-540 ◽  
Author(s):  
Brock Partee ◽  
Scott J. Hollister ◽  
Suman Das

Tissue engineering combines principles of the life sciences and engineering to replace and repair damaged human tissue. Present tissue engineering methods generally require the use of porous, bioresorbable scaffolds to serve as temporary three-dimensional templates to guide cell attachment, differentiation, proliferation, and subsequent regenerate tissue formation. Such scaffolds are anticipated to play an important role in allowing physicians to simultaneously reconstruct and regenerate damaged human tissues such as bone, cartilage, ligament, and tendon. Recent research strongly suggests that the choice of scaffold material and its internal porous architecture significantly influence regenerate tissue structure and function. However, a lack of versatile biomaterials processing and manufacturing methods capable of meeting the complex geometric and compositional requirements of tissue engineering scaffolds has slowed progress towards fully testing these promising findings. It is widely accepted that layered manufacturing methods such as selective laser sintering (SLS) have the potential to address these requirements. We have investigated SLS as a technique to fabricate tissue engineering scaffolds composed of polycaprolactone (PCL), one of the most widely investigated biocompatible, bioresorbable materials for tissue engineering applications. In this article, we report on our development of optimal SLS processing parameters for CAPA® 6501 PCL powder using systematic factorial design of experiments. Using the optimal parameters, we manufactured test scaffolds with designed porous channels and achieved dimensional accuracy to within 3%–8% of design specifications and densities approximately 94% relative to full density. Finally, using the optimal SLS process parameters, we demonstrated the successful fabrication of bone tissue engineering scaffolds based on actual minipig and human condyle scaffold designs.


Author(s):  
Maxime Leblanc Latour ◽  
Maryam Tarar ◽  
Ryan J. Hickey ◽  
Charles M. Cuerrier ◽  
Isabelle Catelas ◽  
...  

AbstractPlant-derived cellulose biomaterials have recently been utilized in several tissue engineering applications. Naturally-derived cellulose scaffolds have been shown to be highly biocompatible in vivo, possess structural features of relevance to several tissues, as well as support mammalian cell invasion and proliferation. Recent work utilizing decellularized apple hypanthium tissue has shown that it possesses a pore size and properties similar to trabecular bone. In the present study, we examined the potential of apple-derived cellulose scaffolds for bone tissue engineering (BTE). Confocal microscopy revealed that the scaffolds had a suitable pore size for BTE applications. To analyze their in vitro mineralization potential, MC3T3-E1 pre-osteoblasts were seeded in either bare cellulose scaffolds or in composite scaffolds composed of cellulose and collagen I. Following chemically-induced differentiation, scaffolds were mechanically tested and evaluated for mineralization. The Young’s modulus of both types of scaffolds significantly increased after cell differentiation. Alkaline phosphatase and Alizarin Red staining further highlighted the osteogenic potential of the scaffolds. Histological sectioning of the constructs revealed complete invasion by the cells and mineralization throughout the entire constructs. Finally, scanning electron microscopy demonstrated the presence of mineral aggregates deposited on the scaffolds after differentiation, and energy-dispersive spectroscopy confirmed the presence of phosphate and calcium. In summary, our results indicate that plant-derived cellulose is a promising scaffold candidate for bone tissue engineering applications.


Author(s):  
Ozan Karaman

The limitation of orthopedic fractures and large bone defects treatments has brought the focus on fabricating bone grafts that could enhance ostegenesis and vascularization in-vitro. Developing biomimetic materials such as mineralized nanofibers that can provide three-dimensional templates of the natural bone extracellular-matrix is one of the most promising alternative for bone regeneration. Understanding the interactions between the structure of the scaffolds and cells and therefore the control cellular pathways are critical for developing functional bone grafts. In order to enhance bone regeneration, the engineered scaffold needs to mimic the characteristics of composite bone ECM. This chapter reviews the fabrication of and fabrication techniques for fabricating biomimetic bone tissue engineering scaffolds. In addition, the chapter covers design criteria for developing the scaffolds and examples of enhanced osteogenic differentiation outcomes by fabricating biomimetic scaffolds.


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