Poly(propylene fumarate)/magnesium calcium phosphate injectable bone composite: Effect of filler size and its weight fraction on mechanical properties

Abstract

This study aimed to produce a composite of poly(propylene fumarate)/magnesium calcium phosphate as a substitutional implant in the treatment of trabecular bone defects. So, the effect of magnesium calcium phosphate particle size, magnesium calcium phosphate:poly(propylene fumarate) weight ratio on compressive strength, Young’s modulus, and toughness was assessed by considering effective fracture mechanisms. Micro-sized (∼30 µm) and nano-sized (∼50 nm) magnesium calcium phosphate particles were synthesized via emulsion precipitation and planetary milling methods, respectively, and added to poly(propylene fumarate) up to 20 wt.%. Compressive strength, Young’s modulus, and toughness of the composites were measured by compressive test, and effective fracture mechanisms were evaluated by imaging fracture surface. In both micro- and nano-composites, the highest compressive strength was obtained by adding 10 wt.% magnesium calcium phosphate particles, and the enhancement in nano-composite was superior to micro-one. The micrographs of fracture surface revealed different mechanisms such as crack pinning, void plastic growth, and particle cleavage. According to the results, the produced composite can be considered as a candidate for substituting hard tissue.

<p>Magnesium-doped Nanostructured Titanium Surface Modulates Macrophage-mediated Inflammatory Response for Ameliorative Osseointegration</p>

“…48 Other studies suggested that the incorporation of Mg in calcium phosphate could modulate the immune environment, in agreement with our results. 49 Therefore, it was speculated that suppressing the inflammation in MgN might result in Mg release. Moreover, the concentration of Mg ions which were applied as anti-inflammation factors in other studies was relatively high (60 mg/L).…”

Sudoku of porous, injectable calcium phosphate cements – Path to osteoinductivity

“…The main interest why injectable materials have gained attention is their ability of filling inaccessible bone defects with an irregular shape due to viscosity of the material. It is only acceptable for viscosity to change if it is still possible for surgeon to inject the material and after the injection the material preserves its form against the influence of body fluids [ 72 , 73 ]. The use of injectable materials may also allow to reach better clinical results and reduce surgery time, which would be beneficial not only for patient, but also for surgeons who will be no longer required to perform long and complex surgeries [ 73 ].…”