Enhancing Osseointegration of TC4 Alloy by Surficial Activation Through Biomineralization Method.

Liang Zhou,Zhenghua Zhang,Zijie Diao,Xiaochun Peng,Meng Pan

doi:10.3389/fbioe.2021.639835

Abstract

Titanium (Ti) alloys have been applied to biomedical implants for a long time. Although Ti alloys are biocompatible, efforts have been continuously made to improve their bone conductivity and osteogenesis for enhancing their performance. Silk fibroin (SF) is a natural biomaterial with excellent biomedical and mechanical properties, and hydroxyapatite (HAP) nanocomposites derived from SF are promising for producing “artificial bone” owing to their biomedical applicability and strong mechanical functions. Therefore, we built an SF coating on the surface of Ti–6Al–4V alloy, and then the incubated SF-coated Ti alloy were immersed in simulated body fluid to induce mineral deposition of HAP on the alloys. The results from Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) analysis, and Attenuated Total Reflection–Fourier Transform Infrared Spectroscopy (ATR–FTIR) confirmed the deposition of a mineral layer on the SF film surface. The proliferation, adhesion, and differentiation of MG-63 were tested, along with the BMP-2, COX-2, and OPG expression and protein content in the MG-63. Both Ti + SF and Ti + SF + HAP groups exhibited significantly better performance than a control Ti group with regard to the cell adhesion, cell proliferation, and protein expression. Furthermore, the hybrid layer comprising HAP and SF delivered more significant improvement of the osseointegration than the SF alone. It is hoped that the proposed methods can be used for constructing modified surfaces on Ti alloys, as they endowed the implants with good osteogenic potential.

Highlights

Titanium (Ti) and Ti alloys are widely used in biomedical devices and components, as well as in cardiac and cardiovascular applications, because of their desirable properties, such as their relatively low modulus, good fatigue strength, formability, machinability, and corrosion resistance (Liu et al, 2004)
To examine and compare the surfaces of the Ti alloy substrate (Ti), Ti alloy coated with Silk fibroin (SF) (Ti + SF), and coated Ti alloy after biomineralization (Ti + SF + HAP), Scanning Electron Microscopy (SEM) was performed
Osseointegration is mainly affected by the surface properties of Ti implants, such as the surface composition and wettability

Summary

Introduction

Titanium (Ti) and Ti alloys are widely used in biomedical devices and components ( as hard tissue replacements), as well as in cardiac and cardiovascular applications, because of their desirable properties, such as their relatively low modulus, good fatigue strength, formability, machinability, and corrosion resistance (Liu et al, 2004). Physical modification via grit-blasting produces a rough surface at the microscale, which increases the degree of mechanical interlocking with the bone tissue (Longhitano et al, 2015). This type of rough surface has random and uncontrolled microstructures, while proteins and cells interact with the implant surface at the nanoscale. Several types of biocompatible coating, such as bioglass (Liu and Miao, 2004; Xue et al, 2017), collagen, and silk fibroin (SF) (Kim et al, 2005; Melke et al, 2016; Yu et al, 2017; Saha et al, 2019), have been introduced to suppress the release of metal ions from implants (Ku et al, 2002). It is necessary to establish a biocompatible coating that can encapsulate a Ti implant and establish a topographical structure with depressions of

Methods

Results

Conclusion