Fabrication and characterization of a bioactive polymethylmethacrylate‐based porous cement loaded with strontium/calcium apatite nanoparticles

Abstract

Polymethylmethacrylate (PMMA)-based cements are used for bone reparation due to their biocompatibility, suitable mechanical properties, and mouldability. However, these materials suffer from high exothermic polymerization and poor bioactivity, which can cause the formation of fibrous tissue around the implant and aseptic loosening. Herein, we tackled these problems by adding Sr 2+ -substituted hydroxyapatite nanoparticles (NPs) and a porogenic compound to the formulations, thus creating a microenvironment suitable for the proliferation of osteoblasts. The NPs resembled the structure of the bone's apatite and enabled the controlled release of Sr 2+ . Trends in the X-ray patterns and infrared spectra confirmed that Sr 2+ replaced Ca 2+ in the whole composition range of the NPs. The inclusion of an effervescent additive reduced the polymerization temperature and lead to the formation of highly porous cement exhibiting mechanical properties comparable to the trabecular bone. The formation of an opened and interconnected matrix allowed osteoblasts to penetrate the cement structure. Most importantly, the gas formation confined the NPs at the surface of the pores, guaranteeing the controlled delivery of Sr 2+ within a concentration sufficient to maintain osteoblast viability. Additionally, the cement was able to form apatite when immersed into simulated body fluids, further increasing its bioactivity.Therefore, we offer a formulation of PMMA cement with improved in vitro performance supported by enhanced bioactivity, increased osteoblast viability and deposition of mineralized matrix assigned to the loading with Sr 2+ -substituted hydroxyapatite NPs and the creation of an interconnected porous structure. Altogether, our results hold promise for enhanced bone reparation guided by PMMA cements.

Bioactive mineralized small intestinal submucosa acellular matrix/PMMA bone cement for vertebral bone regeneration

“…As the active material degrades, it generates a porous structure and osteogenic microenvironment that enhance cell attachment and proliferation. This, in turn, augments the bonding surface between bone and bone cement while concurrently decreasing the elastic modulus [ 27 ]. As the main component of the active material mSIS, SIS has suitable biocompatibility, degradability and mechanical properties for a bone cement additive and contains various growth factors.…”

Synthesis of composite corn starch/hydroxyapatite nanoparticle biomembranes and their effect on mineralization by osteoblasts

“…Hydroxyapatite nanoparticles (HAp) were synthesized by following a methodology adapted from Tomazela et al 29 An aqueous Ca 2+ solution (0.10 mol L −1 ) was prepared and mixed with an aqueous H 3 PO 4 solution (0.06 mol L −1 ), to give a Ca/P ratio equal to 1.67, also found in biological HAp. The solution pH was adjusted to approximately 9.0 with aqueous NH 4 OH solution (1.0 mol L −1 ) under vigorous stirring with the aid of an ultraturrax at 22,000 rpm for 10 min, to favor HAp precipitation.…”

Fe3O4/PMMA with Well-Arranged Structures Synthesized through Magnetic Field-Assisted Atom Transfer Radical Polymerization

“…PMMA is one of the most widely used industrial polymer materials because of its mouldability, biocompatibility [25], extraordinary optical transparency [26], mechanical properties, and weatherability [27]. Several nanoparticles/PMMA composites were synthesized through the ATRP technique in the past few decades to enhance or add various properties to PMMA [28][29][30].…”