Synthesis of Bioactive Hydroxyapatite-Zirconia Toughened Composites for Bone Replacement

2008 ◽  
Vol 57 ◽  
pp. 31-36 ◽  
Author(s):  
Beatrice Cioni ◽  
Andrea Lazzeri ◽  
Giuseppe Gallone ◽  
Giovanni Levita
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Calcium Phosphate ◽  
Antibacterial Properties ◽  
Inorganic Component ◽  
Term Survival ◽  
Bone Replacement ◽  
Mineral Phases ◽  
Hard Tissues

Hydroxyapatite (HAp) is a major inorganic component of human hard tissues, such as bones and teeth, and its content determines their microstructures and physical properties. Artificial HAp shows strong biocompatibility and bioactivity and thus it has found broad applications in tissue engineering for replacing damaged hard tissues. The artificial HAp, however, suffers from its intrinsic low mechanical properties, so to meet mechanical requirements, HAp can be incorporated with stiff mineral phases (mullite, zirconia, alumina). The performance and long-term survival of these biomedical devices are also dependent on the presence of bacteria surrounding the implants. In order to reduce the incidence of implant-associated infections, several treatments have been proposed, e.g. introduction of silver or fluoride in the HAp. The objective of this research is the sintering of composites based on calcium phosphate, mainly HAp supported on zirconia, for bone replacement with better microstructural features. In fact the use of zirconia can enhance the mechanical properties of bioceramics. Moreover the introduction of small amounts of silver, which should improve the antibacterial properties, will be taken into consideration since it is expected also to further toughen the whole structure.

scholarly journals Electrospun PCL Patches with Controlled Fiber Morphology and Mechanical Performance for Skin Moisturization via Long-Term Release of Hemp Oil for Atopic Dermatitis

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Sara Metwally ◽  
Daniel P. Ura ◽  
Zuzanna J. Krysiak ◽  
Łukasz Kaniuk ◽  
Piotr K. Szewczyk ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Atopic Dermatitis ◽  
Mechanical Performance ◽  
Antibacterial Properties ◽  
Skin Condition ◽  
Fiber Morphology ◽  
Suitable Material ◽  
Hemp Oil ◽  
Skin Moisture

Atopic dermatitis (AD) is a chronic, inflammatory skin condition, caused by wide genetic, environmental, or immunologic factors. AD is very common in children but can occur at any age. The lack of long-term treatments forces the development of new strategies for skin regeneration. Polycaprolactone (PCL) is a well-developed, tissue-compatible biomaterial showing also good mechanical properties. In our study, we designed the electrospun PCL patches with controlled architecture and topography for long-term release in time. Hemp oil shows anti-inflammatory and antibacterial properties, increasing also the skin moisture without clogging the pores. It can be used as an alternative cure for patients that do not respond to traditional treatments. In the study, we tested the mechanical properties of PCL fibers, and the hemp oil spreading together with the release in time measured on skin model and human skin. The PCL membranes are suitable material as patches or bandages, characterized by good mechanical properties and high permeability. Importantly, PCL patches showed release of hemp oil up to 55% within 6 h, increasing also the skin moisture up to 25%. Our results confirmed that electrospun PCL patches are great material as oil carriers indicating a high potential to be used as skin patches for AD skin treatment.

Vascularization strategies for tissue engineering for tracheal reconstruction

2021 ◽  
Author(s):  
Fei Sun ◽  
Yi Lu ◽  
Zhihao Wang ◽  
Hongcan Shi
Keyword(s):  
Tissue Engineering ◽  
Cell Metabolism ◽  
Microvascular Network ◽  
Related Factors ◽  
Engineering Technology ◽  
Term Survival ◽  
Tracheal Reconstruction ◽  
Tracheal Replacement ◽  
Therapy Strategies

Tissue engineering technology provides effective alternative treatments for tracheal reconstruction. The formation of a functional microvascular network is essential to support cell metabolism and ensure the long-term survival of grafts. Although several tracheal replacement therapy strategies have been developed in the past, the critical significance of the formation of microvascular networks in 3D scaffolds has not attracted sufficient attention. Here, we review key technologies and related factors of microvascular network construction in tissue-engineered trachea and explore optimized preparation processes of vascularized functional tissues for clinical applications.

scholarly journals Effect of Melt-Derived Bioactive Glass Particles on the Properties of Chitosan Scaffolds

2019 ◽  
Vol 10 (3) ◽  
pp. 38 ◽  
Author(s):  
Hamasa Faqhiri ◽  
Markus Hannula ◽  
Minna Kellomäki ◽  
Maria Teresa Calejo ◽  
Jonathan Massera
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Calcium Phosphate ◽  
Bioactive Glass ◽  
Pore Size ◽  
Glass Content ◽  
Micro Computed Tomography ◽  
Glass Composite ◽  
Composite Scaffolds ◽  
Bioactive Glasses

This study reports on the processing of three-dimensional (3D) chitosan/bioactive glass composite scaffolds. On the one hand, chitosan, as a natural polymer, has suitable properties for tissue engineering applications but lacks bioactivity. On the other hand, bioactive glasses are known to be bioactive and to promote a higher level of bone formation than any other biomaterial type. However, bioactive glasses are hard, brittle, and cannot be shaped easily. Therefore, in the past years, researchers have focused on the processing of new composites. Difficulties in reaching composite materials made of polymer (synthetic or natural) and bioactive glass include: (i) The high glass density, often resulting in glass segregation, and (ii) the fast bioactive glass reaction when exposed to moisture, leading to changes in the glass reactivity and/or change in the polymeric matrix. Samples were prepared with 5, 15, and 30 wt% of bioactive glass S53P4 (BonAlive ®), as confirmed using thermogravimetric analysis. MicrO–Computed tomography and optical microscopy revealed a flaky structure with porosity over 80%. The pore size decreased when increasing the glass content up to 15 wt%, but increased back when the glass content was 30 wt%. Similarly, the mechanical properties (in compression) of the scaffolds increased for glass content up to 15%, but decreased at higher loading. Ions released from the scaffolds were found to lead to precipitation of a calcium phosphate reactive layer at the scaffold surface. This is a first indication of the potential bioactivity of these materials. Overall, chitosan/bioactive glass composite scaffolds were successfully produced with pore size, machinability, and ability to promote a calcium phosphate layer, showing promise for bone tissue engineering and the mechanical properties can justify their use in non-load bearing applications.

scholarly journals Preparation, Structural Characterization, and Biomedical Applications of Gypsum-Based Nanocomposite Bone Cements

2021 ◽  
Author(s):  
Hesham F. El-Maghraby ◽  
Yaser E. Greish
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphate ◽  
Structural Characterization ◽  
Room Temperature ◽  
Bone Cements ◽  
Calcium Phosphate Cements ◽  
Metallic Implants ◽  
Hard Tissues ◽  
Subsequent Conversion ◽  
High Degree

Hard tissues are natural nanocomposites comprising collagen nanofibers that are interlocked with hydroxyapatite (HAp) nanocrystallites. This mechanical interlocking at the nanoscale provides the unique properties of hard tissues (bone and teeth). Upon fracture, cements are usually used for treatment of simple fractures or as an adhesive for the treatment of complicated fractures that require the use of metallic implants. Most of the commercially available bone cements are polymer-based, and lack the required bioactivity for a successful cementation. Besides calcium phosphate cements, gypsum is one of the early recognized and used biomaterials as a basi for a self-setting cementation. It is based on the controlled hydration of plaster of Paris at room temperature and its subsequent conversion to a self-setting solid gypsum product. In our work, we have taken this process further towards the development of a set of nanocomposites that have enhanced bioactivity and mechanical properties. This chapter will outline the formation, characterization, and properties of gypsum-based nanocomposites for bone cement applications. These modified cements can be formulated at room temperature and have been shown to possess a high degree of bioactivity, and are considered potential candidates for bone fracture and defect treatment.

scholarly journals Chitosan/ biphasic calcium phosphate nanofibrous scaffolds for bone tissue engineering

2020 ◽  
pp. 11-17
Author(s):  
Truong Le Bich Tram Truong
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Calcium Phosphate ◽  
Osteogenic Differentiation ◽  
Late Stage ◽  
Biphasic Calcium Phosphate ◽  
Cell Attachment ◽  
The Novel ◽  
Osteogenic Cells ◽  
Nanofibrous Scaffolds

In this article, chitosan/biphasic calcium phosphate (CS/BCP)nanofibers were prepared by electrospinning. From the culture of osteogenic cells, the biocompatibility of CS/BCP nanofibrous substrates was identified and increased by the photocrosslinking. The enhancement in cell attachment and proliferation was caused by the improvement in nanofibers’ mechanical properties. The biocompatibility to osteoblasts was also promoted with the content of BCP. The osteogenic differentiation in early, middle and late stage was encouraged by the addition of BCP on nanofibrous substrates. The CS/BCP nanofibers were highly specific to osteogenic cells, revealed by difficulties in the growth of non-osteogenic cells on this composite nanofibrous scaffold. The novel nanofibrous scaffolds showed great potential in the tissue engineering of bones.

Self-Hardening Calcium Phosphate Composite Scaffold for Bone Tissue Engineering

2009 ◽  
Vol 79-82 ◽  
pp. 19-22 ◽  
Author(s):  
Hua Liu ◽  
Chang Ren Zhou
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Compressive Strength ◽  
Liquid Phase ◽  
Calcium Phosphate ◽  
Bone Tissue Engineering ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Large Diameter ◽  
Fiber Volume

Calcium phosphate cement (CPC) sets in situ to form solid hydroxyapatite, can conform to complex cavity shapes without machining, has excellent osteoinductivity, and is able to be resorbed and replaced by new bone. Therefore, CPC is promising for craniofacial and orthopaedic repairs. However, its low strength and lack of macroporosity limit its use. This study investigated CPC reinforcement with absorbable fibers, the effects of fiber volume fraction on mechanical properties and macroporosity, and the biocompatibility of CPC-fiber composite. The liquid phase of CPC in this study was the weak acidic solution of chitosan. Chitosan has favourable biocompatibility, which has high viscosity in solution. The incorporation of chitosan could improve the handling properties of CPC. The liquid phase contained citric acid could strongly improve the hydration rate of CPC, which shortened the setting time and increased the compressive strength of CPC. In addition, the weak acidic environment around the biomaterials could accelerate the degradation of CPC, which was important to bone tissue engineering. The rationale was that large-diameter absorbable fibers would initially strengthen the CPC graft, then dissolve to form long cylindrical macropores for colonization by osteoblasts. Compressive strength was measured vs. fiber volume fraction from 0% (CPC Control without fibers) to 70%. Animal experiment showed that the material had osteoinductivity and biodegradability when the material was implanted into the muscle pouches in the thigh of rabbits. Compressive strength (mean ± SD; n=3) of CPC with 70% fibers was 0.8± 0.1 MPa. Long cylindrical macropores 100~300 μm in diameter were created in CPC after fiber dissolution, and the CPC-fiber scaffold reached a total porosity of 75.1±1.2% with 70% fibers. The new CPC-fiber formulation had good potentiality of ectopic bone induction. The method of using large-diameter absorbable fibers in bone graft for mechanical properties and formation of long cylindrical macropores for bone ingrowth may be applicable to other tissue engineering materials.

Long-term survival of calcium phosphate-coated dental implants: a meta-analytical approach to the clinical literature

2012 ◽  
Vol 24 (4) ◽  
pp. 355-362 ◽  
Author(s):  
Bart A. J. A. van Oirschot ◽  
Ewald M. Bronkhorst ◽  
Jeroen J. J. P. van den Beucken ◽  
Gert J. Meijer ◽  
John A. Jansen ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Dental Implants ◽  
Analytical Approach ◽  
Term Survival ◽  
Long Term Survival ◽  
Clinical Literature

scholarly journals Detergent-Enzymatic Decellularization of Swine Blood Vessels: Insight on Mechanical Properties for Vascular Tissue Engineering

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Alessandro F. Pellegata ◽  
M. Adelaide Asnaghi ◽  
Ilaria Stefani ◽  
Anna Maestroni ◽  
Silvia Maestroni ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Vascular Tissue ◽  
Complete Removal ◽  
Vascular Tissue Engineering ◽  
Promising Tool ◽  
Complete Cell ◽  
Synthetic Grafts

Small caliber vessels substitutes still remain an unmet clinical need; few autologous substitutes are available, while synthetic grafts show insufficient patency in the long term. Decellularization is the complete removal of all cellular and nuclear matters from a tissue while leaving a preserved extracellular matrix representing a promising tool for the generation of acellular scaffolds for tissue engineering, already used for various tissues with positive outcomes. The aim of this work is to investigate the effect of a detergent-enzymatic decellularization protocol on swine arteries in terms of cell removal, extracellular matrix preservation, and mechanical properties. Furthermore, the effect of storage at −80°C on the mechanical properties of the tissue is evaluated. Swine arteries were harvested, frozen, and decellularized; histological analysis revealed complete cell removal and preserved extracellular matrix. Furthermore, the residual DNA content in decellularized tissues was far low compared to native one. Mechanical testings were performed on native, defrozen, and decellularized tissues; no statistically significant differences were reported for Young’s modulus, ultimate stress, compliance, burst pressure, and suture retention strength, while ultimate strain and stress relaxation of decellularized vessels were significantly different from the native ones. Considering the overall results, the process was confirmed to be suitable for the generation of acellular scaffolds for vascular tissue engineering.

scholarly journals Graphene Oxide Encapsulated Forsterite Scaffolds: Synergistic Influences on Mechanical Properties and Antibacterial Behavior 

2021 ◽  
Author(s):  
A. Najafinezhad ◽  
H. R. Bakhsheshi-Rad ◽  
A. Saberi ◽  
A. A. Nourbakhsh ◽  
M. Daroonparvar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Graphene Oxide ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Antibacterial Properties ◽  
Immersion Test ◽  
Antibacterial Performance ◽  
The Matrix

Abstract It is very desirable to have good antibacterial properties and mechanical properties at the same time for bone scaffolds. Graphene oxide (GO) can increase the mechanical properties and antibacterial performance, while forsterite (Mg2SiO4) as the matrix can increase forsterite/GO scaffolds' biological activity for bone tissue engineering. Interconnected porous forsterite scaffolds were developed by space holder processes for bone tissue engineering in this research. The forsterite/GO scaffolds had a porosity of 77-80%. The mechanism of the mechanical strengthening, antibacterial activity, and cellular function of the forsterite/GO scaffold was evaluated. The findings show that the compressive strength of forsterite/1wt.% GO scaffold was significantly increased, in comparison to forsterite scaffolds without GO. Validation of the samples' bioactivity was attained by forming a hydroxyapatite layer (HAp) on the forsterite/GO surface within in vitro immersion test. The results of cell viability demonstrated that synthesized forsterite scaffolds with low GO did not show cytotoxicity and enhanced cell proliferation. Antibacterial tests showed that the antibacterial influence of forsterite/GO scaffold was strongly correlated with GO concentration. The scaffold encapsulated with 2wt.% GO had the highest bacterial inhibition. As results show, the produced forsterite/1wt.% GO can be an attractive option for bone tissue engineering.

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