Alginate dialdehyde-gelatin (ADA-GEL) constructs incorporating bioactive glass nanoparticles (BGNPs) were produced by biofabrication to obtain a grid-like highly-hydrated composite. The material could induce the deposition of an apatite layer upon immersion in a biological-like environment to sustain cell attachment and proliferation. Composites were formulated with different concentrations of BGNPs synthetized from a sol-gel route, namely 0.1% and 0.5% (w/v). Strontium doped BGNPs were also used. EDS analysis suggested that the BGNPs loading promoted the growth of bone-like apatite layer on the surface when the constructs were immersed in a simulated body fluid. Moreover, the composite constructs could incorporate with high efficiency ibuprofen as a drug model. Furthermore, the biofabrication process allowed the successful incorporation of MG-63 cells into the composite material. Cells were distributed homogeneously within the hydrogel composite, and no differences were found in cell viability between ADA-GEL and the composite constructs, proving that the addition of BGNPs did not influence cell fate. Overall, the composite material showed potential for future applications in bone tissue engineering.

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The present work has explored bioactive glass nanoparticles (BGNPs) and developed strontium-doped nanoparticles (BGNPsSr), envisioning orthopedic strategies compatible with vascularization. The nanoparticles were synthesized by the sol-gel method, achieving a diameter of 55 nm for BGNPs and 75 nm for BGNPsSr, and the inclusion of strontium caused no structural alteration. The nanoparticles exhibited high cytocompatibility for human umbilical vein endothelial cells (HUVECs) and SaOS-2. Additionally, the incorporation of strontium emphasized the tubule networking behavior of HUVECs. Our results demonstrate that the nanoparticle dissolution products encouraged the osteogenic differentiation of human adipose stem cells as it favored the expression of key genes and proteins associated with osteogenic lineage. This effect was markedly enhanced for BGNPsSr, which could prompt stem cell osteogenic differentiation without the typical osteogenic inducers. This study not only supports the hypothesis that BGNPs might play a significant role in osteogenic commitment but also highlights that the designed BGNPsSr is a valuable tool for stem cell "tune-up" in bone tissue engineering applications.

The combination of natural polymers with nanoparticles allowed the development of functional bioinspired constructs. This review discusses the composition, design, and applications of bioinspired nanocomposite constructs based on bioactive glass nanoparticles (BGNPs).