Mesoporous Bioactive Glass Functionalized 3D Ti-6Al-4V Scaffolds with Improved Surface Bioactivity

Abstract

Porous Ti-6Al-4V scaffolds fabricated by means of selective laser melting (SLM), having controllable geometrical features and preferable mechanical properties, have been developed as a class of biomaterials that hold promising potential for bone repair. However, the inherent bio-inertness of the Ti-6Al-4V alloy as the matrix of the scaffolds results in a lack in the ability to stimulate bone ingrowth and regeneration. The aim of the present study was to develop a bioactive coating on the struts of SLM Ti-6Al-4V scaffolds in order to add the desired surface osteogenesis ability. Mesoporous bioactive glasses (MBGs) coating was applied on the strut surfaces of the SLM Ti-6Al-4V scaffolds through spin coating, followed by a heat treatment. It was found that the coating could maintain the characteristic mesoporous structure and chemical composition of MBG, and establish good interfacial adhesion to the Ti-6Al-4V substrate. The compressive strength and pore interconnectivity of the scaffolds were not affected by the coating. Moreover, the results obtained from in vitro cell culture experiments demonstrated that the attachment, proliferation, and differentiation of human bone marrow stromal cells (hBMSCs) on the MBG-coated Ti-6Al-4V scaffolds were improved as compared with those on the conventional bioactive glass (BG)-coated Ti-6Al-4V scaffolds and bare-metal Ti-6Al-4V scaffolds. Our results demonstrated that the MBG coating by using the spinning coating method could be an effective approach to achieving enhanced surface biofunctionalization for SLM Ti-6Al-4V scaffolds.

Scaffolds and coatings for bone regeneration

“…Although BG has good potential for regenerate bone the concentration of boron released is still a concern. A similar conclusion was reached in another study [143]. In this study, it was developed and tested a 3D porous structure of Ti6Al4V coated with BG.…”

Improved Bioactivity of 3D Printed Porous Titanium Alloy Scaffold with Chitosan/Magnesium-Calcium Silicate Composite for Orthopaedic Applications

“…Metal implantable materials usually have both higher mechanical strength and ductility as compared to polymers or ceramic materials [5,6]. Therefore, metal materials are often considered as the first-choice candidates for bone tissue engineering.…”

“…According to the Gibson and Ashby model, introduction of different types of porous structures onto scaffolds can aid in reducing the Young’s modulus thus leading to adjustable mechanical responses such as elastic limit, yield stress, etc. Porous structures allow better bone ingrowth and formation into the scaffolds, thus allowing better material-bone integration [5]. Unfortunately, the inherent bio-inertness of Ti alloys has led to limited improvements in hard tissue regeneration, which may significantly limit their applications in some orthopedic procedures, for example, in the repair of segmental bone defects [5].…”

Simultaneous Regeneration of Bone and Nerves Through Materials and Architectural Design: Are We There Yet?

“…[314,315] Rough surfaces with micropatterns that approximate cell size (20-50 µm) also stimulate bone regeneration. [314,316] Because highly ordered microstructure is not apparent in biological tissues, a randomly varied distribution of spherical pores in the range of 400-600 µm is considered appropriate for bone regeneration. [317] The optimal microstructural parameters for conduit designs for nerve regeneration are 80% porosity, 10-38 µm pore size and ≈0.6 mm wall thickness.…”