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Nano Research

Article Title

Multifunctional mesoporous bioactive glass/upconversion nanoparticle nanocomposites with strong red emission to monitor drug delivery and stimulate osteogenic differentiation of stem cells

Keywords

multifunctional nanocomposites, upconversion, osteoblastic activity, drug release monitoring, bone tumors

Abstract

ABSTRACT For the therapy and regeneration of bone defects resulting from malignant bone tumors, it is necessary to develop multifunctional biomaterials that are able to deliver therapeutic drugs, monitor drug release, and stimulate bone formation. Herein, a multifunctional mesoporous bioactive glass (MBG)/upconversion nanoparticle (UCNP) nanocomposite [UCNPs@SiO2@mSiO2-XCa (X = 0, 5, 10, 15, and 20)] with the ability to deliver anti-cancer drugs, monitor drug release, and stimulate osteogenic differentiation of bone marrow stromal cells (BMSCs) was successfully prepared using a layer-by-layer strategy. The nanocomposite spheres possess a core–shell structure composed of UCNPs and a mesoporous SiO2/Ca layer with a uniform size distribution of 100 nm. The incorporation of Ca into the nanocomposites induced phase transformation from a pure hexagonal phase to a cubic phase, and facilitated the occurrence of red emission, which significantly improved fluorescence penetration for deep tissue imaging. In addition, since the red emission strongly overlaps with the maximum absorbance of the anti-cancer drug zinc phthalocyanine (ZnPc), red luminescence could be strongly quenched by ZnPc. Consequently, drug release could be quantified by monitoring changes in fluorescence intensity. Furthermore, the incorporation of Ca into MBG/UCNP nanocomposites remarkably improved bioactivity, i.e., it stimulated apatite mineralization in simulated body fluids and enhanced cell proliferation and bone-related gene expression in BMSCs for the concentration range of 200–500 μg/mL. Our results suggest that the prepared MBG/UCNP nanocomposites are useful for the therapy and regeneration of bone defects resulting from malignant bone tumors owing to their distinct multifunctionality, including strong red emission and functions in drug-delivery monitoring and osteostimulation.

Graphical Abstract

Publisher

Tsinghua University Press

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