Synthesis, characterization and cytocompatibility of spherical bioactive glass nanoparticles for potential hard tissue engineering applications

Abstract

Nanotechnology offers a new strategy to develop novel bioactive materials, given that nano-scaled biomaterials exhibit an enhanced biocompatibility and bioactivity. In this work, we developed a method for the synthesis of spherical bioactive glass nanoparticles (BGNP) aimed at producing biomaterials for potential use in the repair of hard tissues. The BGNP were prepared using the sol-gel process based on the reaction of alkoxides and other precursors in aqueous media for obtaining the oxide-ternary system with the stoichiometric proportion of 60% SiO2, 36% CaO and 4% P2O5. The system was extensively characterized by Fourier transform infrared, x-ray diffraction and scanning electron microscope/energy-dispersive x-ray spectroscopy with regard to chemical composition, crystallinity and morphology. Moreover, the results suggested the BGNP to be highly bioactive, which was confirmed by the formation of a hydroxyapatite biomimetic layer on the material surfaces upon immersion in simulated body fluid solution. In addition, the bioactivity response toward the developed BGNPs was assessed by direct contact of osteoblast cells using resazurin and alkaline phosphatase assays. The new BGNP have presented a significant increase in the osteoblast in vitro cytocompatibility behavior as compared to similar micro-sized bioactive glass particles. Such improvement in the overall bioactive behavior of BGNP was attributed to the much higher surface area causing enhanced interactions at the cell-nanomaterial interfaces. Hence, based on the results, the BGNP produced are the biomaterials to be potentially utilized in hard tissue engineering applications.

Physical and biological characteristics of nanohydroxyapatite and bioactive glasses used for bone tissue engineering

“…Biomaterials based on bioactive glasses exhibit enhanced biocompatibility and bioactivity upon reducing the glass particle size [117]. The increasing specific surface area and pore volume of bioactive glasses may greatly accelerate the deposition of hydroxyapatite (HA) by the biomimetic process [117,118].…”

“…The increasing specific surface area and pore volume of bioactive glasses may greatly accelerate the deposition of hydroxyapatite (HA) by the biomimetic process [117,118]. In a recent study, de Oliveira et al [117] reported a significantly higher in vitro osteoblast cytocompatibility behavior for bioactive glass nanoparticles (BGNPs), when compared to similar micron-sized particles. The spherical BGNPs (87 ± 5 nm in size) were prepared using the sol-gel process to obtain an oxide-ternary system with the stoichiometric proportion of 60% SiO 2 , 36% CaO, and 4% P 2 O 5 .…”

“…The spherical BGNPs (87 ± 5 nm in size) were prepared using the sol-gel process to obtain an oxide-ternary system with the stoichiometric proportion of 60% SiO 2 , 36% CaO, and 4% P 2 O 5 . The improvement in the overall bioactive behavior of BGNPs was attributed to the enhanced interactions at the cell-nanomaterial interfaces caused by the much higher surface area of the nanoparticles [117]. Moreover, the increased HA nucleation on the nanoparticle surfaces was found to be responsible for the higher cell viability and increased alkaline phosphatase (ALP) activity.…”

Controlling particle size in the Stöber process and incorporation of calcium

“…Understanding the mechanism of calcium incorporation means that it is not necessary to have calcium in the sol from the start of the process. De Oliveira et al [30] synthesised silica nanoparticles using a modified version of the Stӧber process, including phosphate, before filtering the sol and subsequently adding calcium nitrate, but they did not achieve a homogeneous distribution of particles. One possible way of increasing the amount of calcium that can be incorporated would be by use of an alternative calcium source.…”

Kesan Kandungan Fosfat Berbeza terhadap Pembentukan Morfologi Permukaan, Penghabluran, Fasa, Ikatan Kimia dan Kekuatan Mampatan Bio-kaca Sol-Gel Tersinter

“…Walau bagaimanapun, bahan kaca bioaktif ini mempunyai sifat mekanikal yang tidak bersesuaian dengan tulang hidup yang bersifat rapuh dan tidak mempunyai kekuatan mekanikal yang mencukupi menyebabkan bahan ini tidak sesuai digunakan terutamanya di bawah bebanan tinggi (Ma et al 2010). Disebabkan itu, kajian yang dijalankan sebelum ini terhadap bahan kaca bioaktif dilihat terhad pada bentuk serbuk termasuklah yang bersaiz nano (Oliveira et al 2013). Walau bagaimanapun, beberapa ciri dan sifat penting yang dimiliki oleh bahan kaca bioaktif ini menyebabkan bahan ini amat diperlukan dalam aplikasi yang lebih meluas termasuklah pada galas bebanan tinggi.…”