<p>Carbon Nanotube Reinforced Hydroxyapatite Nanocomposites As Bone Implants: Nanostructure, Mechanical Strength And Biocompatibility</p>

Abstract

PurposeHydroxyapatite (HA) is a biologically active ceramic which promotes bone growth, but it suffers from relatively weak mechanical properties. Multi-walled carbon nanotubes (MWCNTs) have high tensile strength and a degree of stiffness that can be used to strengthen HA; potentially improving the clinical utility of the bone implant.MethodsHA was precipitated by the wet precipitation method in the presence of pristine (p) or functionalised (f) MWCNTs, and polyvinyl alcohol (PVA) or hexadecyl trimethyl ammonium bromide (HTAB) as the surfactant. The resulting composites were characterised and the diametral tensile strength and compressive strength of the composites were measured. To determine the biocompatibility of the composites, human osteoblast cells (HOB) were proliferated in the presence of the composites for 7 days.ResultsThe study revealed that both the MWCNTs and surfactants play a crucial role in the nucleation and growth of the HA. Composites made with f-MWCNTs were found to have better dispersion and better interaction with the HA particles compared to composites with p-MWCNTs. The mechanical strength was improved in all the composites compared to pure HA composites. The biocompatibility study showed minimal LDH activity in the media confirming that the composites were biocompatible. Similarly, the ALP activity confirmed that the cells grown on the composites containing HTAB were comparable to the control whereas the composites containing PVA surfactant showed significantly reduced ALP activity.ConclusionsThe study shows that the composites made of f-MWCNTs HTAB are stronger than pure HA composites and biocompatible making it a suitable material to study further.

Rotary Jet-Spun Polycaprolactone/Hydroxyapatite and Carbon Nanotube Scaffolds Seeded with Bone Marrow Mesenchymal Stem Cells Increase Bone Neoformation

“…However, nHap has poor mechanical strength restricting its use . Strategies to improve this problem without sacrificing its biocompatibility include incorporating reinforcement materials, such as zirconia, nanodiamond, alumina, carbon fibers, CNTs, and others. , CNTs have aroused intense interest due to their outstanding physiological properties to mimic the nanoscale dimensions of nHap and collagen fibers in natural bone. , The superficial modification of CNTs by exposure to oxygen plasma introduces polar groups that change their wettability and ability for incorporation into polymer composites. , This hydrophilic characteristic facilitates the adsorption of proteins essential in mediating cell adhesion, growth, and the formation of an extracellular matrix. , Therefore, the combination of CNTs with synthetic polymeric materials can be effective for promoting bone tissue engineering applications.…”

Suitability of Chitosan Scaffolds with Carbon Nanotubes for Bone Defects Treated with Photobiomodulation

“…There is evidence of favorable properties and biocompatibility of chitosan electrospun composite biomaterials for a variety of uses [ 19 ]. Carbon nanotubes can also be used to improve chitosan scaffolds, which may represent an attractive option due to their tensile strength, high flexibility, promising bioactivity and good electrical conductivity [ 20 , 21 , 22 ].…”

HA/HDPE Reinforced with MWCNTs for Bone Reconstruction and Replacement Application

“…This research group were continued to improve composites for the highest mechanical performance and bioactivity materials for bone substitute [15,16]. Several studied have attempted to apply CNT as a new method to the expectation of improving the mechanical properties of polyethene [17] and hydroxyapatite [18]. For bone tissue engineering, many studies have concluded that the use of hydroxyapatite with polyethene [19,20] and CNT [21] provides excellent results in mechanical and biocompatibility properties.…”