Functionalized Polymeric Membrane with Enhanced Mechanical and Biological Properties to Control the Degradation of Magnesium Alloy

Abstract

To achieve enhanced biological response and controlled degradation of magnesium alloy, a modified biodegradable polymer coating called polycaprolactone (PCL) is fabricated by a thermal approach in which the heat treatment neither alters the chemical composition of the PCL membrane nor the rate of magnesium ion release, pH value, or weight loss, compared with the untreated sample. The changes in the crystallinity, hydrophilicity, and oxygen content of heat-treated PCL coating not only improve the mechanical adhesion strength between the coating and magnesium substrate but also enhance the biological properties. Moreover, the thermally modified sample can lead to higher spreading and elongation of osteoblasts, due to the enhanced hydrophilicity and CO to CO functional group ratio. In the analyses of microcomputed tomography from one to four weeks postoperation, the total volume of new bone formation on the heat-treated sample is 10%-35% and 70%-90% higher than that of the untreated and uncoated controls, respectively. Surprisingly, the indentation modulus of the newly formed bone adjacent to the heat-treated sample is ≈20% higher than that of both controls. These promising results reveal the clinical potential of the modified PCL coating on magnesium alloy in orthopedic applications.

Regulation of extracellular bioactive cations in bone tissue microenvironment induces favorable osteoimmune conditions to accelerate in situ bone regeneration

“…Hence, it seems to be the new strategy for designing next-generation orthopedic substitutes by developing biomaterials with an osteoimmunomodulatory function to promote osteogenesis and, subsequently, generate a suitable osteoimmune microenvironment. Recently, stimulation of bone formation by magnesium ions released from biomaterials (e.g., metallic implant, bio-polymer, and bio-ceramic) has drawn much attention owing to the high efficacy, low cost, and reduced complication [ [32] , [33] , [34] , [35] ]. The delivery of magnesium ions at a suitable range of concentrations contributes to osteogenesis by promoting osteoblastic activity and inhibiting osteoclastic activity and facilitating the bone mineralization process [ 36 ].…”

Stepwise 3D-spatio-temporal magnesium cationic niche: Nanocomposite scaffold mediated microenvironment for modulating intramembranous ossification

“…Studies have shown that Mg-incorporated biomaterial surfaces could increase cellular attachment [ 64 , 65 ]. Our previous studies have also found an optimal range of Mg 2+ levels, which could upregulate cell viability and proliferation of human osteoblasts (SaOS-2) and mouse pre-osteoblasts (MC3T3-E1) [ [66] , [67] , [68] ]. Accordingly, the T-Moderate should be the most appropriate composite with the above data.…”

TRPM7 kinase-mediated immunomodulation in macrophage plays a central role in magnesium ion-induced bone regeneration

“…Magnesium, its alloys [10][11][12][13] and derivatives [14][15][16] have been extensively studied as replacements for non-degradable metallic implants e.g., titanium alloys in bone surgeries. Mg 2+ modified biomaterials have shown superior osteogenic capacity in many reports [14][15][16][17][18][19][20][21] .…”