In Vitro Degradation and In Vivo Biocompatibility of Strontium-Doped Magnesium Phosphate-Reinforced Magnesium Composites

Abstract

Magnesium is projected for use as a degradable orthopedic biomaterial. However, its fast degradation in physiological media is considered as a significant challenge for its successful clinical applications. Bioactive reinforcements containing Mg-based composites constitute one of the promising approaches for developing degradable metallic implants because of their adjustable mechanical behaviors, corrosion resistance, and biological response. Strontium is a trace element known for its role in enhancing osteoblast activity. In this study, bioactive SrO-doped magnesium phosphate (MgP)-reinforced Mg composites containing 1, 3, and 5 wt % MgP were developed through the casting route. The influence of the SrO-doped MgP reinforcement on degradation behaviors of the composites along with its cell–material interactions and in vivo biocompatibility was investigated. The wt % and distribution of MgP particles significantly improved the mechanical properties of the composite. HBSS immersion study indicated the least corrosion rate (0.56 ± 0.038 mmpy) for the Mg–3MgP composite. The higher corrosion resistance of Mg–3MgP leads to a controlled release of Sr-containing bioactive reinforcement, which eventually enhanced the cytotoxicity as measured using MG-63 cell–material interactions. The in vivo biocompatibility of the composite was evaluated using the rabbit femur defect model. Micro-computed tomography (μ-CT) and histological analysis supported the fact that Mg–3MgP maintained its structural integrity and enhanced osteogenesis (50.36 ± 2.03%) after 2 months of implantation. The results indicated that the Mg–MgP composite could be used as a degradable internal fracture fixation device material.

Synergistic Effects of Cerium and Hot Forging on Biodegradation, Antibacterial Properties, and In Vivo Biocompatibility of Microalloyed Mg–Zr–Sr Alloys

“…The corroded product was removed from the samples using a solution of 180 g/L CrO 3 for 7–10 min according to their surface conditions. The average corrosion rate (ACR) was determined in millimeter per year (mmpy) by the following formula ACR = Z 0.25em * normalΔ w A 0.25em * t 0.25em * ρ Z = 8.76 × 10 4 , Δ w = weight change before and after immersion (gm), A = surface area of the sample exposed to medium (cm 2 ), ρ = density (gm/cm 3 ), and t = immersion time (h).…”

Platelet-rich fibrin as an autologous biomaterial for bone regeneration: mechanisms, applications, optimization

“…MgP 2 Sr-dPRF was prepared by uniformly coating decellularized platelet-rich fibrin (dPRF) on the surface of Sr-doped MgP ceramics, and the results showed that relative to the trabecular bone pattern of MgP 2 S scaffold sections, MgP 2 Sr-dPRF sections showed vascular osteogenic parenchyma containing abundant Haversian canals, bone sinus gaps, and tubular structures. The osteoblasts, osteocytes, and osteoclasts were in reasonable proportions, and the number of new bone formations and maturation was significantly increased in the MgP 2 Sr-dPRF group ( Dutta et al, 2022 ). Furthermore, a recent study prepared a gel-like biomaterial, the L-PRF/PLGA composite graft, by adding platelet-rich fibrin gel to a porous PGLA biodegradable scaffold.…”

Effects of the multiscale porosity of decellularized platelet-rich fibrin-loaded zinc-doped magnesium phosphate scaffolds in bone regeneration

“…The biocompatibility of MgP ceramics has been well-proven through in vitro and in vivo studies. 8,9 Magnesium (Mg) ions play a vital role in skeletal growth, DNA stabilization, and bone metabolism by regulating cellular-level signalling mechanisms, which in turn stimulate the adhesion and proliferation of osteoblastic cells. 10,11 The role of magnesium ions in bone remodelling, as well as the higher degradation rate, and superior mechanical properties of MgP over CaP have led to MgP being considered a good contender for bone grafts.…”