Papers by Keyword: Bioactivity

Abstract: Titanium alloys, especially titanium-niobium alloy have been reported as a potential biomaterial with good biocompatibility and non-toxicity. However, there is a lack of studies in alkaline surface treatment of new beta titanium alloy fabricated by vacuum arc melting (VAM) and powder metallurgy (PM) technique with high addition of niobium percentage. The purpose of this research was to examine the feasibility of surface modification on new beta Ti-40wt% Nb alloy in sodium hydroxide solution in order to form bioactive alkaline titanate layer. The characterization involved in this study is X-ray diffraction analysis (XRD), scanning electron microscope (SEM), microhardness, density measurement and optical microscope (OM). Development of amorphous alkaline titanate layer consisted of titanium hydrate, sodium titanate and oxide mixture of titanium oxide, niobium, niobium oxide were revealed by XRD. SEM shows titanate hydrogel layer form on Ti alloy PM thicker than on Ti alloy VAM. Microhardness and density measurement for Ti alloy VAM is greater than Ti alloy PM. OM shows porous surface on Ti alloy PM compare to VAM. This research suggests that the formation of sodium titanate layer on the surface of Ti-Nb alloy enhance bioactivity with better osteointegration and present higher formation of apatite which is crucial for the desired biomedical implant.

Abstract: Polyetheretherketone (PEEK) as alternate biomaterial to traditional metallic implant materials has become greater important. At the same time have greater chemical resistance, mechanical properties, biocompatibility and radiolucency, making it convenient for use as dental and orthopedic implants. In the present study the biological behavior was evaluated of polymer composites based polyetheretherketone combined with various nano hydroxyapatite and nano titanium dioxide blending up to (1.5 wt%). The bioactivity of the specimens was evaluated by investigation apatite formation after immersion for 7 days and 14 days in simulated body fluid (SBF). XRD and SEM were used to approve the bioactivity of the specimens. Cell viability, proliferation, and the cell attachment activity of L929 mouse fibroblast cells was evaluated after (1, 3 & 5) days by MTT assay. Antibacterial property of the specimens versus S. aureus was observed with optical density methods. The results detected that the apatite-like layer formation was clearly observed on specimens after immersion for different period in simulated body fluid (SBF). Moreover, Results of MTT assay recorded the PEEK specimens excited the activity of fibroblasts and therefore a high cytocompatibility was noticed and specimens showed antibacterial properties against S. aureus.

Abstract: Bioactive glasses based on the SrBGs: 45SiO2 - 6P2O5 - 15SrO - 34CaO, 5Zn-SrBGs (wt.%): 45SiO2 - 6P2O5 - 15SrO - 29CaO - 5ZnO (wt.%), and 5Ce-SrBGs: 45SiO2 - 6P2O5 - 15SrO - 29CaO – 5CeO (wt.%) were successfully synthesised through the sol-gel process under the acid condition. The concentration of nitric acid at 0.01M was an optimal condition to accelerate the hydrolysis and polycondensation reactions in these systems. SEM images showed the primary particle nucleus growth in the morphological structure of the SrBGs, 5Zn-SrBGs, and 5Ce-SrBGs. FTIR spectra indicated the incorporation of therapeutic cations in the glass structure whilst maintaining the morphological structure. XRD and SEM suggested the crystalline apatite formation on the surface of BGs after the BGs were incubated in the simulated body fluid (SBF) at pH 7.4 for 21 days. EDS-SEM indicated the apatite formation whilst containing doping ions in the glass structure. All three BGs formulations could promote the murine pre-osteoblast cell (MC3T3-E1) cell proliferation at the concentration between 200-250 µg/mL and have no in vitro cytotoxicity on MC3T3-E1 cells up to the concentration of 1mg/mL.

Abstract: Silica-calcium phosphate nanocomposite (SCPC) is a porous bioactive resorbable bioactive ceramics. Incorporating apatite bone cement (AC) formulation of tetracalcium phosphate-dicalcium phosphate dihydrate and SCPC has contributed to the higher mechanical strength of a new prototype apatite cement formulation. This in-vitro experiment aims to investigate the bioactivity of AC formulation using simulated body fluid (SBF). The samples consist of two groups of AC formulations (n=4). The first group, AC with 10% SCPC and the second group AC without SCPC, was immersed in the SBF for 14 days. The samples before and after immersion were analyzed by X-Ray Diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDS), and Scanning Electron Microscope (SEM). The samples' size and degree of crystallinity were analyzed statistically using Shapiro-Wilk, Levene, and Mann-Whitney test. As a result, there was no significant difference in the crystal size and the degree of the crystallinity of both samples. The surface morphology of all samples were coated with hydroxyapatite after immersing in the SBF solution. Both AC formulations with and without SCPC have bioactivity as the bone substitute materials. Combining AC with SCPC50 is a promising method to improve the bioactivity and mechanical strength of calcium phosphate bone cement.

Abstract: There are many requirements for biomaterials used in the applications of bone tissue engineering, besides their biocompatibility, they should exhibit acceptable mechanical properties to mimic bone properties. Many research areas in bioactive materials for bone tissue engineering focused on producing new bioactive glass and ceramic compositions containing a trace of inorganic elements (such as Mg, Sr, Cu, Zn) to combine the mechanical properties and bioactivity. In the present study bioglass-MgO composite material has been used to produce Diopside (CaMgSi₂O₆) by the sintering process. The compact samples were made from a mixture powder of (7, 15)wt% MgO and binary bioglass 70Si-30Ca sintered at 1100 ᵒC for 2 hr. The XRD results confirmed the presence of diopside and wollastonite CaSiO₃ in the case of using 7wt.% MgO while the structure was completely diopside at 15 Wt.% MgO. Physical properties, compressive strength, and hardness were investigated, as well as biodegradation behavior and bioactivity in human saliva were inspected. The results confirmed improving the mechanical properties along with increasing MgO as well as proved the ability to form hydroxyapatite on the surface when exposed to human saliva. These findings demonstrated the positive role of MgO in the mechanical properties of 70Si-30Ca bioactive glass besides producing diopside as a good candidate for hard tissue engineering.

Abstract: This study concerns the evaluation of the bioactivity and cells response of strontium (Sr) doped sol-gel derived S53P4 bioglass due to Sr induced osteoblast. Moreover it prevents in-vitro osteoclastic activity and is clinically used as osteoporosis treatment. The different amount of Sr was doped into the S53P4 bioglass formulation (53.82%SiO₂-1.72%P₂O₅-22.64%Na₂O-(21.76-x)%CaO-x%SrO) (x=0, 3 and 5 mol %) and synthesized via sol-gel method. These samples were denoted as 0Sr, 3Sr and 5Sr respectively. After soaking in Hank's balanced salt solution (HBSS) for 7 and 14 days, the apatite formation was examined using X-ray powder diffraction (XRD) and scanning electron microscope (SEM) techniques. Proliferation and alkaline phosphatase activity were evaluated using osteoblastic cell line MC3T3-E1. The XRD and SEM findings confirmed the hydroxyapatite (HA) structure on the bioglass surface after soaking. More intense HA peaks were observed in 3Sr specimen on 7 day while in 5Sr specimen on 14 day. Meanwhile, 3Sr specimen showed the highest cells proliferation and ‌ significant difference in alkaline phosphatase (ALP) activity than 0Sr and 5Sr. As a result, this finding indicates that S53P4 bioglass with 3 mol % SrO (3Sr) is a good candidate for bone tissue engineering because it allows for optimum cell proliferation and ALP activity while also having a high bioactivity efficiency.

Abstract: Cordierite powders were synthesized via a melt-quench method. The samples were melted at 1550°C for 4 hours and immediately quenched in distilled water. The bioglass ceramic frit was milled and calcined to produce cordierite powders. After that, cordierite was treated with calcium acetate as a calcium salt in order to enhance the bioactivity of cordierite. The powders were immersed in calcium acetate solution for 24 hours and dried in the oven at 80°C for 24 hours. The mixtures were pressed into pellet form for bioactivity testing. Then, cordierite pellets were soaked in simulated body fluid (SBF) solution for 7 days. SEM micrographs show the formation of the hydroxyapatite layer on its surface after soaking in SBF solution. While EDX analysis shows the presence of calcium after the treatment. The presence of cordierite and hydroxyapatite phases were confirmed by XRD analysis.

Abstract: Polyetheretherketone is a semi-crystalline thermoplastic polymer, that so with heat treatments, it is possible to get different properties which are very important for the material performance. Heat treatment is a broadly utilized to develop the semi-crystalline polymers properties. In the present investigation, annealing of polyetheretherketone (PEEK) was carried out at temperatures above its glass transition temperature (Tg) to study its effects upon the biological conduct of the control and PEEK ternary composites. The bioactivity of the specimens was evaluated by investigating the apatite formation after immersion for different periods in a simulated body fluid (SBF). The biocompatibility of specimens was assessed by MTT assay. Additionally, the antibacterial property of the specimens versus S. aureus was observed with the optical density methods. The results manifested that the formation of hydroxyapatite was obviously observed on specimens after immersion for (7 and 14 days) in the simulated body fluid (SBF). Otherwise, the results of MTT assay recorded the PEEK specimens that excited the activity of fibroblasts, and therefore a high cytocompatibility was noticed and the specimens revealed antibacterial properties against S. aureus. So, the results of the bioactivity, biocompatibility and antibacterial tests in vitro demonstrated that the heat treatment enhanced biological behavior.

Abstract: Direct pulp capping (DPC) is one of the treatment plans for deep caries with mechanical pulp exposure that can replace invasive treatments. This study aimed to assess the apatite-forming ability and solubility of a calcium phosphate cement (CPC) modified with bioactive glass (BG) as a potential bioactive material for DPC.Three different biomaterials including CPC, BG, and CPC/BG composite were used in this study. For bioactivity evaluation, specimens were immersed in simulated body fluid (SBF) for 5 time periods (3, 7, 14, 21 and 28 days). The samples were analyzed by SEM, EDS and XRD to confirm the formation of hydroxyapatite. The solubility was calculated by measuring the initial and final mass according to the ISO 6876 specifications.According to the results of this study, SEM observations and XRD analysis revealed higher formation of hydroxyapatite crystals in the CPC/BG Group and also at the shorter time than those in the CPC and BG groups. Concerning solubility, the CPC group showed the most solubility after 7 days and the BG group showed the lowest one. At this time the difference between CPC and BG groups was statistically meaningful (p value=0.003). After 30 days the CPC/BG group exhibited the lowest solubility value. At the day 30, the CPC and BG groups showed significant difference in their solubility (p value=0.04).).Based on the results, addition of BG to CPC improved bioactivity properties of CPC material and did not affect its solubility adversely. The CPC/BG composite seems to be a promising material for DPC. Further in vivo studies are needed to prove its clinical success.

Abstract: Chitosan-hydroxyapatite composite doped with strontium was synthesised via in situ co-precipitation method. Physicochemical properties of the composite obtained were analysed using X-ray diffraction (XRD), infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and Thermogravimetry with differential thermal analysis (DT-TGA). The synthesized composite was subjected to bioactivity studies in simulated body fluid (SBF). The calcium release from the sample in SBF was measured using atomic absorption spectroscopy (AAS). The physicochemical properties and bioactivity of the novel composite was compared with that of hydroxyapatite, strontium doped hydroxyapatite and chitosan hydroxyapatite. The in vitro bioactivity studies of the novel composite showed that it has a higher release of Ca²⁺ in the SBF compared to the other samples. The novel material was also found to induce more Ca²⁺ deposition after 28 days of immersion in the SBF. Hence, the novel composite material has the potential to be used as biomaterials for clinical application.