Magnetic Hydroxyapatite Bone Substitutes to Enhance Tissue Regeneration: Evaluation In Vitro Using Osteoblast-Like Cells and In Vivo in a Bone Defect

Abstract

In case of degenerative disease or lesion, bone tissue replacement and regeneration is an important clinical goal. In particular, nowadays, critical size defects rely on the engineering of scaffolds that are 3D structural supports, allowing cellular infiltration and subsequent integration with the native tissue. Several ceramic hydroxyapatite (HA) scaffolds with high porosity and good osteointegration have been developed in the past few decades but they have not solved completely the problems related to bone defects. In the present study we have developed a novel porous ceramic composite made of HA that incorporates magnetite at three different ratios: HA/Mgn 95/5, HA/Mgn 90/10 and HA/Mgn 50/50. The scaffolds, consolidated by sintering at high temperature in a controlled atmosphere, have been analysed in vitro using human osteoblast-like cells. Results indicate high biocompatibility, similar to a commercially available HA bone graft, with no negative effects arising from the presence of magnetite or by the use of a static magnetic field. HA/Mgn 90/10 was shown to enhance cell proliferation at the early stage. Moreover, it has been implanted in vivo in a critical size lesion of the rabbit condyle and a good level of histocompatibility was observed. Such results identify this scaffold as particularly relevant for bone tissue regeneration and open new perspectives for the application of a magnetic field in a clinical setting of bone replacement, either for magnetic scaffold fixation or magnetic drug delivery.

Harnessing magnetic-mechano actuation in regenerative medicine and tissue engineering

“…However, such concerns have been dissipated by a number of in vivo tests demonstrating that magnetic nanofibrous scaffolds of PCL implanted subcutaneously [93] and magnetic hydroxyapatite/collagen scaffolds implanted in rabbit distal femoral epiphysis and tibial mid-diaphysis did not appear to cause inflammation [94]. Furthermore, magnetic hydroxyapatite, prepared with different ratios of magnetic particles, when implanted in rabbit bone critical size defects produced in the condyle region, had similar biocompatibility to hydroxyapatite alone [95]. Indeed, it has been observed that granting magnetic properties to biomaterials can lead to a significant increase in cell proliferation [95,96].…”

“…Furthermore, magnetic hydroxyapatite, prepared with different ratios of magnetic particles, when implanted in rabbit bone critical size defects produced in the condyle region, had similar biocompatibility to hydroxyapatite alone [95]. Indeed, it has been observed that granting magnetic properties to biomaterials can lead to a significant increase in cell proliferation [95,96]. The mechanisms underlying this stimulation still need to be elucidated.…”

A Preliminary Study of the Effect of Static Magnetic Field Acting on Rat Bone Marrow Mesenchymal Stem Cells during Osteogenic Differentiation In Vitro

“…Some physical stimulation, such as electrical, mechanical, and magnetic stimulation, play key roles in the development and restoration of many tissues, for instance bone tissues, and those stimulations act effectively on bone formation [1][2][3] . Additionally, Static Magnetic Field (SMF) has a wide range of biological effects as a physical factor 3) .…”

“…Additionally, Static Magnetic Field (SMF) has a wide range of biological effects as a physical factor 3) . Studies have demonstrated that SMF could promote bone repairing and formation 4,5) .…”

Magnetic Polymer Nanocomposite for Medical Application

“…This approach enables the long--term drug delivery process and supports tissue regeneration to be controlled adequately to requirement, even for a long period of time after implantation. Additionally, * corresponding author; e-mail: swietek@agh.edu.pl magnetic implants, due to presence of particles possessing magnetic properties, also enhance and accelerate cell proliferation and bone tissue formation under an applied static magnetic eld [16,17].…”