Synthesis and Characterization of Mesoporous Mg- and Sr-Doped Nanoparticles for Moxifloxacin Drug Delivery in Promising Tissue Engineering Applications.

Georgia K Pouroutzidou,Antonios D Anastasiou,Christina Pappa,Liliana Liverani,Aldo R Boccaccini,Anna Theocharidou,Dimitrios N Bikiaris,Evi Christodoulou,Maria Lazaridou,Lambrini Papadopoulou,Eleana Kontonasaki,Anastasia Beketova,Konstantinos S Triantafyllidis,Ioannis Tsamesidis

doi:10.3390/ijms22020577

Abstract

Mesoporous silica-based nanoparticles (MSNs) are considered promising drug carriers because of their ordered pore structure, which permits high drug loading and release capacity. The dissolution of Si and Ca from MSNs can trigger osteogenic differentiation of stem cells towards extracellular matrix calcification, while Mg and Sr constitute key elements of bone biology and metabolism. The aim of this study was the synthesis and characterization of sol–gel-derived MSNs co-doped with Ca, Mg and Sr. Their physico-chemical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDX), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence spectroscopy (XRF), Brunauer Emmett Teller and Brunauer Joyner Halenda (BET/BJH), dynamic light scattering (DLS) and ζ-potential measurements. Moxifloxacin loading and release profiles were assessed with high performance liquid chromatography (HPLC) cell viability on human periodontal ligament fibroblasts and their hemolytic activity in contact with human red blood cells (RBCs) at various concentrations were also investigated. Doped MSNs generally retained their textural characteristics, while different compositions affected particle size, hemolytic activity and moxifloxacin loading/release profiles. All co-doped MSNs revealed the formation of hydroxycarbonate apatite on their surface after immersion in simulated body fluid (SBF) and promoted mitochondrial activity and cell proliferation.

Highlights

Bone repair and regeneration are still challenging issues for orthopedics and maxillofacial surgery
The Fourier transform infrared spectroscopy (FTIR) spectra of all mesoporous silica-based nanoparticles (MSNs) presented the characteristic bands of amorphous silicate glasses (Figure 1)
We evaluated the ability of the synthesized NPs to load and release moxifloxacin

Summary

Introduction

Bone repair and regeneration are still challenging issues for orthopedics and maxillofacial surgery. It is anticipated that 2–5% of all the procedures related to implant placement will present bacterial infections [1] but this number can be increased to 50% when open fracture is involved [2]. For treatment of infected bone defects, typical procedures suggest the surgical removal of the involved bone fragments in combination with systemic antibiotics administration, and the utilization of bone grafts to regenerate the lost bone structure [3]. All the above underline the need for the development of novel materials that can promote bone regeneration while at the same time being able to administrate antibiotic substances locally to prevent bacterial infection

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