Nanocements produced from mesoporous bioactive glass nanoparticles

Current biomedical cements rely on calcium phosphate powders with micrometer-scale particles. These materials require high powder-to-liquid ratios for setting. Researchers have long sought injectable materials with improved surface area and bioactivity. Prior studies established the importance of ion release in bone regeneration. However, the role of ultrafine particles in cement performance remains unclear. This gap motivated the investigation of mesoporous bioactive glass nanoparticles. The unique properties of these particles suggest potential for novel cement forms. This paper explores how nanopowder composition affects cement behavior.

The study aimed to develop a new cement form using mesoporous bioactive glass nanoparticles. Researchers wanted to compare this material to conventional calcium phosphate cement. They focused on powder-to-liquid ratios and cementation mechanisms. The goal was to understand how nanoparticle structure influences setting. They also sought to measure surface area and ion release properties. The team aimed to assess biological responses to the new cement. They wanted to determine if this material supports cell activity better. The study tested both in vitro and in vivo performance metrics.

Researchers used mesoporous bioactive glass nanoparticles as the cement base. They mixed the powder with aqueous solution at low ratios. Transmission electron microscopy revealed cementation mechanisms. X-ray diffraction and Fourier transform infrared spectroscopy tracked chemical changes. X-ray photoelectron spectroscopy and nuclear magnetic resonance provided surface and structural data. Simulated body fluid immersion tested apatite formation. Protein adsorption levels were measured using spectrophotometric techniques. The team evaluated ion release rates over two weeks. Cell viability and osteogenesis were assessed using rat mesenchymal stem cells and human umbilical vein endothelial cells.

The nanopowder hardened at powder-to-liquid ratios of 0.4-0.5. This is significantly lower than conventional cement's 2.0-3.0 range. Cementation involved ionic dissolution and reprecipitation of Si and Ca. Amorphous nano-islands formed between particles, creating a network. The material exhibited a surface area of 78.7 m²/g, nine times higher than conventional cement. Immersion in simulated body fluid produced 10 nm apatite nanocrystallites. This is much smaller than the 55 nm observed in conventional cement. The nanocement adsorbed proteins at 160 times higher levels than CPC. Continuous Si and Ca ion release occurred over two weeks.

The study demonstrated that mesoporous bioactive glass nanoparticles form a novel cement. This material hardens at lower powder-to-liquid ratios than conventional cement. The unique cementation mechanism involves ionic dissolution and reprecipitation. The high surface area and ultrafine apatite formation suggest improved bioactivity. Protein adsorption levels were significantly higher than conventional cement. Ion release stimulated cell responses in both rMSCs and HUVECs. In vivo tests showed enhanced neo-blood vessel formation with nanocement implants. The material exhibited signs of osteoinductivity and osteoconduction in rat calvarial defects.