Improved fracture toughness and integrated damage sensing capability by spray coated CNTs on carbon fibre prepreg Part A Applied science and manufacturing

The state-of-the-art on calcium orthophosphate (CaPO4)-containing biocomposites and hybrid biomaterials suitable for biomedical applications is presented. Since these types of biomaterials offer many significant and exciting possibilities for hard tissue regeneration, this subject belongs to a rapidly expanding area of biomedical research. Through the successful combinations of the desired properties of matrix materials with those of fillers (in such systems, CaPO4 might play either role), innovative bone graft biomaterials can be designed. Various types of CaPO4-based biocomposites and hybrid biomaterials those are either already in use or being investigated for biomedical applications are extensively discussed. Many different formulations in terms of the material constituents, fabrication technologies, structural and bioactive properties, as well as both in vitro and in vivo characteristics have been already proposed. Among the others, the nano-structurally controlled biocomposites, those containing nanodimensional compounds, biomimetically fabricated formulations with collagen, chitin and/or gelatin, as well as various functionally graded structures seem to be the most promising candidates for clinical applications. The specific advantages of using CaPO4-based biocomposites and hybrid biomaterials in the selected applications are highlighted. As the way from a laboratory to a hospital is a long one and the prospective biomedical candidates have to meet many different necessities, the critical issues and scientific challenges that require further research and development are also examined.

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Calcium Orthophosphate-Containing Biocomposites and Hybrid Biomaterials for Biomedical Applications

Hydroxyapatite (HAp) has significant biological activity, degradability, and osteoconductivity. In recent decades, it has been widely used in dentistry, anti-tumour drug carriers, and orthopaedic repair. However, hydroxyapatite has limit features which are poor mechanical properties for directly inducing tooth enamel remineralization, particle size and morphology issues on drug delivery and brittleness for bone transplantation. This article summarizes the problems encountered in the preparation, application, and modification of hydroxyapatite in the above-mentioned fields and the current research progress, combining theory with experiment. Therefore, the greatest significance of this review is to comprehensively integrate and argue the forms and effects of nHA-based biomaterials, which provides a theoretical basis for the application of this material and help readers have clear insights into future research.

Recent advances in biomedical engineering of nano-hydroxyapatite including dentistry, cancer treatment and bone repair

A large number of recent studies deal with the application of nano materials to different medicine areas, application that led to a new discipline known as nanomedicine. It comprises the processes of diagnosing, treating, curing, preventing diseases and also dealing with traumatic injury, relieving pain and preserving/improving human health by using nano materials. Among nano materials, an important place belongs to the group of natural and synthetic polymer nanocomposites. These are made up of an organic polymer matrix and a mineral, organic or metallic nanofiller. The properties of polymer nanocomposites depend on the characteristics of the components and on the interaction polymer-nanofiller. Polymer nanocomposites offer to modern medicine new opportunities for generate products for antibacterial treatment, tissues engineering, cancer therapy, medical imaging, dental applications, drug delivery, etc.

Polymer nanocomposites in medicine

Advances in ultra high molecular weight polyethylene/hydroxyapatite composites for biomedical applications: A brief review.

Nanomechanical and tribological behavior of hydroxyapatite reinforced ultrahigh molecular weight polyethylene nanocomposites for biomedical applications

Ultrahigh molecular weight polyethylene–based nanocomposites reinforced with nano-sized hydroxyapatite particles were fabricated using internal mixer and compression molding with different weight percent of the nano-hydroxyapatite. In this study, first, hydroxyapatite nanoparticles were synthesized by sol–gel. Then, the mechanical and biological properties of nanocomposites were studied by tensile test and proliferation and cell adhesion assays using MG-63 osteoblast cells, respectively. Results of the tensile test showed that incorporation of 50 wt% nano-hydroxyapatite led to a 345.64% and 57.58% increase in Young's modulus and yield strength (compared to the pure ultrahigh molecular weight polyethylene), respectively. The effect of the nano-hydroxyapatite powders on the MG-63 osteoblast cells behavior was compared to those of a composite (positive control) and a negative control samples. Scanning electron microscopy micrographs revealed that cell–biomaterial interaction was carried out on the surface of...

Tensile and biocompatibility properties of synthesized nano-hydroxyapatite reinforced ultrahigh molecular weight polyethylene nanocomposite:

Porous scaffolds of Ti-6Al-4V were produced by mixing of this alloy with different amount of magnesium (Mg) powders. The mixtures were compacted in steel die by applying uniaxial pressure of 500 MPa before sintering the compacts in sealed quartz tubes at 900 °C for 2 h. Employing Archimedes׳ principle and Image Tool software, the total and open volume percentages of porosities within the scaffolds were found to be in the range of 47–64% and 41–47%, respectively. XRD results of titanium before and after sintering showed that no contamination, neither oxides nor nitrides formed during processes. Compressive properties of the scaffolds were studied using an Instron machine. The observed compressive strength and Young׳s module of the scaffolds were in the range of 72–132 MPa, and 37–47 GPa, respectively. Cell attachment and proliferation rate of MG-63 on porous samples were investigated. The results showed that proliferation rate increased with increasing Mg content. However no clear differences were observed between samples regarding cell attachment, so that bridges were observed in all cell gaps within the scaffolds.

Biocompatibility and compressive properties of Ti-6Al-4V scaffolds having Mg element.

The non-isothermal crystallization and melting behavior of ultrahigh molecular weight polyethylene reinforced with short carbon fibers (SCFs) and nano-SiO2 particles were investigated using differential scanning calorimetry. The melting tests were conducted at the cooling rates of 10, 20 and 30 °C min−1 prior to heating at the rate of 10 °C min−1. Melting peak temperatures increased by the incorporation of SCFs and remained almost constant by adding nano-SiO2 particles. The crystallization tests were performed at the cooling rates of 10, 20, 30 and 40 °C min−1. Ozawa–Avrami model was proved the best model to describe the kinetics of the composites. SCFs increased the absolute crystallinity of the neat polymer; however, adding various amounts of nano-SiO2 leaded to a decrease in the absolute crystallinity.

Non-isothermal melting and crystallization behavior of UHMWPE/SCF/nano-SiO 2 hybrid composites

Ultrahigh molecular weight polyethylene (UHMWPE) nanocomposite reinforced with hydroxyapatite (HA) nanoparticles was prepared incorporating nanoparticles into UHMWPE and paraffin oil using internal mixer and then hot press. Scanning electron microscope (SEM) images revealed that nanosized particles were homogeneously dispersed in UHMWPE by the internal mixer. In this study, at first HA nanoparticles were synthesised by sol–gel method, and then effects of nanoparticles on the mechanical properties of the HA/UHMWPE nanocomposites were studied by tensile test. Results showed that the composite with the 50wt% nano-HA exhibited a Young’s modulus and yield strength 345.64 and 57.58% higher than that of pure UHMWPE, respectively.

Seyed Ali Mirsalehi

Papers

Nanomechanical and tribological behavior of hydroxyapatite reinforced ultrahigh molecular weight polyethylene nanocomposites for biomedical applications

Tensile and biocompatibility properties of synthesized nano-hydroxyapatite reinforced ultrahigh molecular weight polyethylene nanocomposite:

Biocompatibility and compressive properties of Ti-6Al-4V scaffolds having Mg element.

Non-isothermal melting and crystallization behavior of UHMWPE/SCF/nano-SiO 2 hybrid composites

Synthesis of nano-HA and the effects on the mechanical properties of HA/UHMWPE nanocomposites