Characterization and Performance of Magnesium Doped Bioactive Glass Nanoparticles

The bioactive glass and related biomaterials have become increasingly popular, and have also attracted the research interest of many researchers in recent years due its special performance and tissue engineering application. In this study, to create a material with a variety of properties Mg doped hollow bioactive glass (Mg-HBG) of 80SiO2-5P2O5-10CaO-5MgO system had been produced by using a sol-gel method. The porous structure nanoparticles were specifically made by employing the cetyltrimethylammonium bromide (CTAB) as a surfactant. Magnesium was selected as a doped material with HBG, because it is the most existing cations in the human body which helps for bone metabolism as well as it has antibacterial property. Based on different investigations resulted nanoparticle with the inclusion of the lower molar fractions magnesium has good tested result. For a drug model vancomycin hydrochloride (VAN) was used in this study and it has also good antibacterial activity effect. These findings help the possibility of using Mg-HBG nanoparticles to treat infectious bone abnormalities by demonstrating their compatibility with antibiotics, drug loading and release behavior.

Preparation and bioactivity of sol-gel macroporous bioactive glass

Bioactive glass is well known for its ability of bone regeneration, and sol-gel bioactive glass has many advantages compared with melt-derived bioactive glass. 3-D scaffold prepared by the sol-gel method is a promising substrate material for bone tissue engineering and large-scale bone repair. Porous sol-gel glass in the CaO-SiO2-P205 system with macropores larger than 100 μm was prepared by the addition of stearic acid as a pore former. The diameter of the pore created by the pore former varied from 100 to 300 μm. The formation of a hydroxyapatite layer on the glass was analyzed by studying the surface of the porous glass by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Raman spectra after they had been immersed in simulated body fluid （SBF） for some time, and the porous glass shows good bioactivity.

In vitro Mineralization Behavior of the Sol-gel Derived Bioglass/Collegen Composite Porous Scaffold

The porous scaffold of the sol-gel derived bioactive glass （BG） in the system CaO-P2O5-SiO2 was treated with the type Ⅰ collagen solution. The pore walls of the scaffold were covered by the collagenous network. The in vitro mineralization behavior of the sol- gel derived bioglassl collegen composite porous scaffold was investigated by immersion in supersaturated calcification solution （ SCS ） at 37℃ for different times, XRD , FTIR, SEM/ EDAX techniques were applied to analyze the crystalline phases, morphology and composition of the minerals formed on the pore walls of the scaffold. It was found that with increasing of immersion time, the morphology of reaction products on the pore walls changed from the spherical particles of calcium phosphate to the flake-like HCA crystals.

Influence of Synthesis Parameters on the Structure, Pore Morphology and Bioactivity of a New Mesoporous Glass

The main objective of the present work was to investigate the effect of surfactant type and synthesis temperature on the structure, porosity and the bioactivity of 92S6 (92% SiO2, 6% CaO, and 2% P2O5 mol %) mesoporous sol-gel glasses. The aim was to provide a basis for controlling the bioactive behavior of the different 92S6 samples used for tissue regeneration and for biomedical engineering in order to obtain sufficient performances by controlling the porosity of the glass. In this paper, a series of mesoporous bioactive glasses were synthesized using three different surfactants (C10H20BrN, C19H42BrN, C22H48BrN) at different aging temperatures (20°C, 40°C and 60°C). The surfactant was removed by calcination, which was carried out by increasing the temperature to 650°C for 6 h. A comparison among these synthesized glasses was conducted and the research emphasis was placed on the synthesis temperature and the surfactant type dependence on the textural properties and particularly porosity that were ultimately responsible for glass bioactivity.

PHBV膜与PHBV/SGBG复合材料联合促进骨再生

【目的】探讨聚羟基丁酸/羟基戊酸共聚酯(PHBV)膜与3-羟基丁酸-co-3-羟基戊酸共聚物/溶胶-凝胶生物活性玻璃(PHBV/SGBG)多孔复合材料促进骨再生的能力。【方法】实验共采用8只健康杂种犬,每只犬分别于左、右胫骨各制作2个直径为5mm的穿通骨髓腔的圆洞形骨缺损区,间隔2cm。双侧胫骨共建立4个骨缺损模型,将其随机分为四组:A组,骨缺损内填充柱状PHBV/SGBG材料,并在其上方覆盖PHBV膜;B组,骨缺损上方覆盖PHBV膜;C组,骨缺损内填充柱状PHBV/SGBG材料;D组,不放置任何东西。分别于术后2、4、8、12周各处死2只动物,组织学观察不同实验条件下骨缺损区新骨组织生长情况。【结果】所有植入材料组(A组、B组、C组)均未出现植入物排异反应。其中A组术后2周时,已有明显的新生骨岛形成;术后12周骨缺损区新生成熟骨组织再生。与其它实验组相比,A组的骨缺损修复最早,新生骨的质量最好,骨结构与周围正常骨基本一致。而空白对照组中,骨痂修复中可见纤维组织形成,骨缺损区修复不全。【结论】PHBV膜覆盖技术和PHBV/SGBG复合材料植入技术结合,具有促进骨缺损区的骨组织修复的协同作用;PHBV膜和PHBV/SGBG复合材料有望成为应用于引导骨组织再生的新一代材料。

Multifunctional zinc ion doped sol-gel derived mesoporous bioactive glass nanoparticles for biomedical applications

Mesoporous bioactive glasses have been widely investigated for applications in bone tissue regeneration and,more recently,in soft tissue repair and wound healing.In this study we produced mesoporous bioactive glass nanoparticles(MBGNs)based on the SiO2-CaO system.With the intention of adding subsidiary biological function,MBGNs were doped with Zn2+ions.Zn-MBGNs with 8 mol%ZnO content were synthesized via microemulsion assisted sol-gel method.The synthesized particles were homogeneous in shape and size.They exhibited spherical shape,good dispersity,and a size of 130±10 nm.The addition of zinc precursors did not affect the morphology of particles,while their specific surface area increased in comparison to MBGNs.The presence of Zn2+ions inhibited the formation of hydroxycarbonate apatite(HCAp)on the particles after immersion in simulated body fluid(SBF).No formation of HCAp crystals on the surface of Zn-MBGNs could be observed after 14 days of immersion.Interestingly,powders containing relatively high amount of zinc released Zn2+ions in low concentration(0.6-1.2 mg L^−1)but in a sustained manner.This releasing feature enables Zn-MBGNs to avoid potentially toxic levels of Zn2+ions,indeed Zn-MBGNs were seen to improve the differentiation of osteoblast-like cells(MG-63).Additionally,Zn-MBGNs showed higher ability to adsorb proteins in comparison to MBGNs,which could indicate a favourable later attachment of cells.Due to their advantageous morphological and physiochemical properties,Zn-MBGNs show great potential as bioactive fillers or drug delivery systems in a variety of applications including bone regeneration and wound healing.

Effect of different sol-gel synthesis processes on microstructural and morphological characteristics of hydroxyapatite-bioactive glass composite nanopowders

The aim of this work was to study the influence of the different synthesis processes on microstructural and morphological characteristics and distribution of hydroxyapatite-bioactive glass(HAp-BG)composite nanopowders obtained by sol-gel method.HAp-BG composite nanopowders with 20 wt%bioactive glass were prepared using a sol-gel method via four routes:(I)mixing the prepared HAp solution with BG solution before aging time;(II)mixing the prepared BG solution with the prepared HAp gel after gelation;(III)mixing the calcined BG nanopowders with the prepared HAp solution;and(IV)mixing the two prepared calcined nanopowders by mechanochemical activation.The prepared nanopowders were evaluated and studied by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectrometer(EDS),Fourier transform infrared(FTIR),transmission electron diffraction(TEM)and Brunauer-Emmet-Teller(BET)method to investigate the phase structure,microstructure and morphology,functional groups,and the size and distribution of nanopowders.Results indicated that morphology,crystallinity,crystallite size and specific surface area(SSA)of the powders are highly correspondent to the process and type of synthesis method.These findings suggest that the modified sol-gel derived HAp-BG composite nanopowders are expected to efficiently provide a possibility to produce a good candidate to use for fabrication of a bulk nanostructured HAp-BG composite for bone tissue engineering.

Sol-gel synthesis,properties and protein loading/delivery capacity of hollow bioactive glass nanospheres with large hollow cavity and mesoporous shell

Hollow nanospheres exhibit unique properties and find a wide interest in several potential applications such as drug delivery.Herein,novel hollow bioactive glass nanospheres(HBGn)with large hollow cavity and large mesopores in their outer shells were synthesized by a simple and facile one-pot ultrasound assisted sol-gel method using PEG as the core soft-template.Interestingly,the produced HBGn exhibited large hollow cavity with ~43 nm in diameter and mesoporous shell of ~37 nm in thickness and 7 nm pore size along with nanosphere size around 117 nm.XPS confirmed the presence of Si and Ca elements at the surface of the HBGn outer shell.Notably,HBGn showed high protein loading capacity(~570 mg of Cyto c per 1 g of HBGn)in addition to controlled protein release over 5 d.HBGn also demonstrated a good in vitro capability of releasing calcium(Ca^(2+):170 ppm)and silicate(SiO_(4)^(4-):78 ppm)ions in an aqueous medium over 2 weeks under physiological-like conditions.Excellent in vitro growth of bone-like hydroxyapatite nanocrystals was exhibited by HBGn during the soaking in SBF.A possible underlying mechanism involving the formation of spherical aggregates(coils)of PEG was proposed for the formation process of HBGn.

Mineral formation on dentin induced by nano-bioactive glass

The object of this study was to evaluate the effect of bioactive glass （BG） size on mineral formation on dentin surfaces. Totally demineralized dentin discs were treated using BG suspensions with different particle sizes： i.e., microscale bioactive glass （m-BG）, submicroscale bioactive glass （sm-BG） and nanoscale bioactive glass （n-BG）. Field-emission scanning electron microscopy and 3D profile measurement laser microscopy were used to observe the surface morphology and roughness. It was found that all BG particles could promoted mineral formation on dentin surfaces, while plug-like depositions were observed on the dentin discs treated by n-BG and they were more acid-resistant. The present results may imply that n-BG has potential clinical application for dentin hypersensitivity treatment.

Preparation and characterization of bioactive glass tablets and evaluation of bioactivity and cytotoxicity in vitro

In this study, the SiO2eCaOeP2O5 ternary component of bioactive glass particles were successfullysynthesized by sol-gel method, then the bioactive glass particles were pressed into tablets with drypressing molding technology. The physicochemical structure, in-vitro bioactivity and biocompatibility ofBG tablets were characterized by various methods, such as XRD、SEM、FTIR, etc. The results showedthat the sol-gel bioactive glass particle was distinguished with its amorphous structure and micron-size.After being soaked in Tris-Hcl solution for 15 d, the bioactive glass tablets didn't collapse. Also, themineralization assay in vitro showed that the bioactive glass tablets had good capability of inducing theformation of hydroxycarbonate apatite (HCA) after being immersed in simulated body fluid (SBF). Inaddition, the cytotoxicity assay indicated that the osteoblast (MC3T3) grew well on the surface ofbioactive glass tablets. According to the above results, the bioactive glass tablets presented good mechanicalstrength, excellent apatite-forming activity and high biocompatibility, which demonstratedtheir potential applications in the field of bone defect repairing.

新型纳米仿生骨植入材料体内降解性能的初步研究

目的研究新型纳米仿生骨植入材料的体内降解性。方法制备犬胫骨骨缺损模型,实验组植入材料,空白对照组不作处理。术后2,4,8,12周取材,观察该材料的体内降解性及骨再生的效果。结果材料植入体内2周已开始降解,12周时材料基本完全降解,光镜下及电镜下均未见材料颗粒的残留,骨缺损区新骨充填,骨再生量明显优于对照组。结论新型纳米仿生骨植入材料体内降解速度快,材料降解后为新生骨组织所替代。