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

2021 ◽  
Author(s):  
Hesham F. El-Maghraby ◽  
Yaser E. Greish

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.

Author(s):  
Yu Qu ◽  
Hui Zhuang ◽  
Meng Zhang ◽  
Yufeng Wang ◽  
Dong Zhai ◽  
...  

Although calcium phosphate cements (CPC) have been clinically used to repair bone defects caused by bone tumor resection, traditional CPC cannot kill the remaining tumor cells after surgery and prevent...


2012 ◽  
Vol 727-728 ◽  
pp. 1164-1169 ◽  
Author(s):  
Mônica Beatriz Thürmer ◽  
Rafaela Silveira Vieira ◽  
Juliana Machado Fernandes ◽  
Wilbur Trajano Guerin Coelho ◽  
Luis Alberto Santos

Calcium phosphate cements have bioactivity and osteoconductivity and can be molded and replace portions of bone tissue. The aim of this work was to study the obtainment of α-tricalcium phosphate, the main phase of calcium phosphate cement, by wet reaction from calcium nitrate and phosphoric acid. There are no reports about α-tricalcium phosphate obtained by this method. Two routes of chemical precipitation were evaluated and the use of two calcinations temperatures to obtain the phase of cement. The influence of calcination temperature on the mechanical properties of cement was evaluated. Cement samples were characterized by particle size analysis, X-ray diffraction, mechanical strength and scanning electron microscopy. The results demonstrate the strong influence of synthesis route on the crystalline phases of cement and the influence of concentration of reactants on the product of the reaction, as well as, on the mechanical properties of cement.


2016 ◽  
Vol 124 (2) ◽  
pp. 180-183 ◽  
Author(s):  
Toru OGASAWARA ◽  
Takenori SAWAMURA ◽  
Hirotaka MAEDA ◽  
Akiko OBATA ◽  
Hitoshi HIRATA ◽  
...  

1995 ◽  
Vol 14 (1) ◽  
pp. 4-5 ◽  
Author(s):  
E. FernÁndez ◽  
M. P. Ginebra ◽  
O. Bermúdez ◽  
M. G. Boltong ◽  
F. C. M. Driessens ◽  
...  

2010 ◽  
Vol 64 (18) ◽  
pp. 2028-2031 ◽  
Author(s):  
Bai Feng ◽  
Meng Guolin ◽  
Yuan Yuan ◽  
Liu Changshen ◽  
Wang Zhen ◽  
...  

2008 ◽  
Vol 81 (1) ◽  
pp. 96-109 ◽  
Author(s):  
M. A. J. van der Mee ◽  
J. G. P. Goossens ◽  
M. van Duin

Abstract Maleated ethylene/propylene copolymer (MAn-g-EPM) was thermoreversibly crosslinked using different routes, i.e. ionic interactions (ionomers), hydrogen bonding and a combination thereof. Microphase separation into polar MAn-rich aggregates occurs for MAn-g-EPM and all crosslinked materials, which act as physical crosslinks. The crosslink density does not change upon modification, but the strength of the aggregates is significantly increased, resulting in improved mechanical properties. All materials except the potassium ionomer with high degree of neutralization (DN) could be remolded into homogeneous and smooth films without chemical changes, indicating that the crosslinks are truly thermoreversible. A comparison of the mechanical properties, i.e. tensile properties and compression set at room temperature, for the different crosslinking routes showed that the poorest properties are obtained for hydrogen-bonded materials. The potassium ionomer with high DN has the best properties by far, but is difficult to process. Comparable mechanical properties are obtained for zinc ionomers, potassium ionomers with low DN and amide-salts, which combine ionic interactions and hydrogen bonding. The amide-salts have a distinct advantage in processing over the ionomers, since they can be compression molded at much lower temperatures, although high temperatures should be avoided because of irreversible imide formation.


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