Presence Of Simulated Body Fluid Research Articles

Synthesis and characterization of mesoporous bioactive glass nanoparticles loaded with peganum harmala for bone tissue engineering

Globally, there is an increase in a number of bone disorders including osteoarthritis (OA), osteomyelitis, bone cancer, and etc., which has led to a demand for bone tissue regeneration. In order to take use of the osteogenic potential of natural herbs, mesoporous bioactive glass nanoparticles (MBGNs) have the ability to deliver therapeutically active chemicals locally. MBGNs influence bioactivity and osteointegration of materials making them suitable for bone tissue engineering (BTE). In the present study, we developed Peganum Harmala (P. harmala) loaded MBGNs (PH-MBGNs) synthesized via modified Stöber process. The MBGNs were analyzed in terms of surface morphology, chemical make-up, amorphous nature, chemical interaction, pore size, and surface area before and after loading with P. harmala. A burst release of drug from PH-MBGNs was observed within 8 h immersion in phosphate buffer saline (PBS). PH-MBGNs effectively prevented Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) from spreading. Furthermore, PH-MBGNs developed a hydroxyapatite (HA) layer in the presence of simulated body fluid (SBF) after 21 days, which confirmed the in-vitro bioactivity of MBGNs. In conclusion, PH-MBGNs synthesized in this work are potential candidate for scaffolding or a constituent in the coatings for BTE applications.

Development of Zn-2Cu-xMn/Mg Alloys for Orthopedic Applications: Mechanical Performance to In Vitro Degradation under Different Physiological Environments.

Zinc (Zn) and its alloys are considered futuristic biodegradable materials for their acceptable mechanical properties, suitable corrosion rate, and good biocompatibility. In this study, we report newly developed biodegradable Zn-2Cu-xMn/Mg (x = 0, 0.1, and 0.5) alloys, aiming to achieve good mechanical strength with excellent elongation, desirable wear resistance, and suitable corrosion rate. The effect of Mn/Mg addition on the structural, mechanical, wear, and degradation behaviors of the Zn-2Cu-xMn/Mg alloys was thoroughly investigated. Degradation and tribological behaviors of the alloys were explored in the presence of simulated body fluid (SBF), Dulbecco's modified Eagle medium (DMEM), and DMEM with a 10% fetal bovine serum (FBS) solution. Alloy elements and hot rolling improve their mechanical properties significantly due to precipitation hardening, grain refinement, and solid solution strengthening owing to the formation of MnZn13 and Mg2Zn11 phases. Among all the alloys, the Zn-2Cu-0.5Mn alloy achieved the highest ultimate tensile strength (UTS) of ∼405 MPa and yield strength (YS) of ∼293 MPa with an excellent elongation of ∼51%. The corrosion behavior of the alloys as determined by a potentiodynamic polarization study under different solutions follows the sequence Zn-2Cu < Zn-2Cu-0.5Mn < Zn-2Cu-0.1Mn < Zn-2Cu-0.1Mg < Zn-2Cu-0.5Mg. The corrosion rate by immersion testing for 30 and 90 days also follows the same sequence. The corrosion rate in different solutions follows the order SBF > DMEM + 10%FBS > DMEM. The addition of Mn/Mg also improves the wear resistance and slows the wear rate under wet conditions. The bending test results also indicate the highest bending strength of ∼375 MPa for the Zn-2Cu-0.5Mn alloy, among all the alloys. The bending and tensile strengths deteriorate continuously after the immersion for 30 and 90 days in the solution of SBF, DMEM, and DMEM + 10%FBS. Therefore, the Zn-2Cu-xMn/Mg (x = 0.1 and 0.5) alloys can be considered potential biodegradable implant materials.

Drug loading of tannic acid crosslinked hydroxyapatite/gelatin composites via spray dryer and kinetic studies

The present study aims at studying the loading and release of 5-Fluorouracil (5-FU) drug from hydroxyapatite/gelatin (HAp-GEL) composites. Composites were produced in the presence of simulated body fluid (SBF) at pH 7.4 and 37 °C implementing tannic acid (TA) as a cross-linking agent. HAp-GEL composites were characterized by X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. 5-FU was loaded on HAp-GEL composites via spray dryer through encapsulation. Drug release kinetics studies revealed that 5-FU release from HAp-GEL composites were best fitted to first order kinetic model with R2 values in the range of 0.85–0.98. Gelatin and TA contents of the composites were found to affect the release profiles and initial burst values, with higher initial burst values at greater gelatin contents. pH dependent release of 5-FU was observed from produced HAp-GEL composites with higher release at physiological pH (7.4) conditions. Current study suggest that produced 5-FU loaded HAp-GEL composites hold potential as carrier for 5-FU drug in clinical applications.

In vitro degradation and dry sliding wear behaviour of AZ31-Sn/Al2O3 nano metal matrix composites in simulated body fluid for biomedical application

In this research, tin was added to the AZ31/2Al2O3 magnesium metal matrix composite to investigate its influence on degradation rate in the presence of simulated body fluid (SBF) and wear behaviour in dry conditions. The AZ31- xSn/2Al2O3 ( x = 0, 2, 4, 6, 8, and 10 wt%) composites were manufactured using the bottom pouring stir casting route. The microstructure of the manufactured AZ31/2Al2O3 and AZ31- xSn/2Al2O3 composites revealed that they were composed of the α-Mg solid solution and the intermetallic compound □-Mg17Al12, which was situated near the grain boundaries. When tin was added, the Sn-rich intermetallic compound Mg2Sn was formed, increasing the volume fraction of the Mg2Sn phase. Compared to AZ31/2Al2O3 composite, the wear test revealed that AZ31/2Al2O3 composites containing Sn particles exhibited a higher ability to generate more stable tribo-layers at higher applied loads, which protected the worn surface and reduced the wear rate. The wear resistance of composites was improved primarily by the behaviour of the tribo-layer in the wear process. The degradation rates (mm/year) of the AZ31 composites were carried out for 72 h in SBF. The degradation rate was reduced when the Sn content in the AZ31/2Al2O3 composite was increased to 6 wt% and then increased with further Sn addition. It was observed that when the amount of Sn particles increases up to 6 wt%, the severity of the degradation decreases.

Longitudinally aligned inner-patterned silk fibroin conduits for peripheral nerve regeneration

Peripheral nerve injuries represent a major clinical challenge, if nerve ends retract, there is no spontaneous regeneration, and grafts are required to proximate the nerve ends and give continuity to the nerve. The nerve guidance conduits (NGCs) presented in this work are silk fibroin (SF)-based, which is biocompatible and very versatile. The formation of conduits is obtained by forming a covalently cross-linked hydrogel in two concentric moulds, and the inner longitudinally aligned pattern of the SF NGCs is obtained through the use of a patterned inner mould. SF NGCs with two wall thicknesses of ~ 200 to ~ 400 μm are synthesized. Their physicochemical and mechanical characteristics have shown improved properties when the wall thickness is thicker such as resistance to kinking, which is of special importance as conduits might also be used to substitute nerves in flexible body parts. The Young modulus is higher for conduits with inner pattern, and none of the conduits has shown any salt deposition in presence of simulated body fluid, meaning they do not calcify; thus, the regeneration does not get impaired when conduits have contact with body fluids. In vitro studies demonstrated the biocompatibility of the SF NGCs; proliferation is enhanced when iSCs are cultured on top of conduits with longitudinally aligned pattern. BJ fibroblasts cannot infiltrate through the SF wall, avoiding scar tissue formation on the lumen of the graft when used in vivo. These conduits have been demonstrated to be very versatile and fulfil with the requirements for their use in PNR.

Fretting tribocorrosion properties of anodized TiNbSn implant alloy

Titanium and its alloys have poor wear resistance, and the biological response to generated wear debris leads to aseptic loosing and pathological bone resorption. In the fretting wear of artificial hip joints, a significant part of the wear surface is contacted by elastic deformation, and electrochemical anodization is a promising method to control the mechanical properties of the surface and improve wear resistance. To suppress wear debris generation and metal ions elution from implant materials into body fluids, the tribocorrosion properties of a newly developed anodized TiNbSn implant alloy were evaluated in the presence of simulated body fluid and compared to those of pure Ti. During anodization under high voltage, spark discharge occurred due to dielectric breakdown occurred for the TiNbSn electrode, but not for the Ti electrode. The primary phase of the anodic oxide layer on TiNbSn alloy was rutile TiO2, whereas that on Ti was anatase TiO2. The anodic oxide layer on TiNbSn had a higher thickness, roughness, and surface area than that on anodized Ti. In addition, the hardness and exfoliation strength were higher than those of Ti. The coefficient of friction of anodized TiNbSn in fretting tests was similar or slightly lower than that of anodized Ti, and the open circuit potential remained unchanged for anodized TiNbSn but shifted to a more negative voltage for anodized Ti. The results suggest that the hard and strongly-adhered rutile TiO2 on TiNbSn formed by spark discharge during the high-voltage anodization process improves fretting wear resistance and reduces the generation of wear debris and elution of metal ions.

Fabricating PTFE nanocomposites via in situ filling of hydroxyapatite nanowires and their tribological performance

Excellent tribological performance and biocompatibility are required for the biomaterials that can be used for artificial acetabular cups. Hydroxyapatite nanowires, herein, were in situ filled into PTFE, and the resulting PTFE nanocomposites presented a high dispersion degree and a reliable interface adhesion. There were significant improvements in stiffness, heat-resistant and hydrophobic capabilities observed. It was observed that there were drastically decreased coefficients of friction and volume wear rates, which were determined by a sliding friction against a high-speed steel ring in the presence of simulated body fluid, and less and shallower plough furrows on the worn surfaces of the in situ fabricated nanocomposite specimens. The enhancements in tribological performance might be attributed to the one-dimensioned hydroxyapatite nanowires with the characteristics of both nano- and micro-sized materials and outstanding properties in mechanics, thermology, tribology. And the in situ fabrication method contributed to a reliable stress transfer between the matrix and the nanofillers, and led to a marked enhancement in stiffness, wear resistance and friction reduction of the nanocomposites fabricated with respect to the pristine PTFE even at a mass fraction of as low as 0.5%. The fabrication method and the resulting PTFE nanocomposites may suggest a way to a promising application in acetabular cups or other artificial joints/human tissues. • PTFE composites are fabricated via in situ filling of hydroxyapatite nanowires. • The nanofillers present a high dispersity and a reliable interface combination. • Mechanical, thermal and tribological properties are improved by in situ filling. • In situ filling contributes to dispersion, interfacial adhesion, and stress transfer. • Filler characteristics and fabrication method impart enhanced tribological performance.

Tailoring Biotribological Performance of Polytetrafluoroethylene Nanocomposites through Control of Diameters and Aspect Ratios of In Situ Filled Hydroxyapatite Nanowires

Excellent biocompatibility and biotribological performance are necessary for artificial acetabular cups in total hip replacement. Herein, polytetrafluoroethylene (PTFE) nanocomposites are fabricated via an in situ filling of hydroxyapatite nanowires. The resulting nanocomposites are characterized and evaluated by sliding friction against a high‐speed steel ring in the presence of simulated body fluid. Markedly enhanced hydrophobicity, heat resistance, and stiffness are observed for the fabricated nanocomposites in comparison with the matrix PTFE. The ethanol/water ratios for the in situ fabrication of the nanocomposites showed a predominant role in the diameters and aspect ratios of the hydroxyapatite nanowires filled in the nanocomposites. This might be related to the competition between the nucleation and growth of the hydroxyapatite crystals under applied synthetic conditions because the concentration of ethanol can influence the size and morphology of the oleic acid micelles. Furthermore, the diameters and aspect ratios of the nanofiller are found a decisive role in the tribological performance of the resulting PTFE nanocomposites, and those fabricated using a low ethanol/water ratio showed an enhanced diameter and aspect ratio and remarkable improvement in biotribological performance. The fabrication method is believed promising for the design and controllable synthesis of artificial acetabular cups or other artificial tissues.

Corrosion Resistance and Surface Bioactivity of Ti6Al4V Alloy after Finish Turning under Ecological Cutting Conditions

The influence of cooling conditions and surface topography after finish turning of Ti6Al4V titanium alloy on corrosion resistance and surface bioactivity was analyzed. The samples were machined under dry and minimum quantity lubrication (MQL) conditions to obtain different surface roughness. The surface topographies of the processed samples were assessed and measured using an optical profilometer. The produced samples were subjected to electrochemical impedance spectroscopy (EIS) and corrosion potential tests (Ecorr) in the presence of simulated body fluid (SBF). The surface bioactivity of the samples was assessed on the basis of images from scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analysis. The inspection of the surfaces of samples after turning under dry and MQL conditions revealed unevenly distributed precipitation of hydroxyapatite compounds (Ca/P) with a molar ratio in the range of 1.73–1.97. Regardless of the cutting conditions and surface roughness, the highest values of Ecorr ~0 mV were recorded on day 7 of immersion in the SBF solution. The impedance characteristics showed that, compared to the MQL conditions, surfaces machined under dry conditions were characterized by greater resistance and the presence of a passive layer on the processed surface. The main novelty of the paper is the study of the effect of ecological machining conditions, namely, dry and MQL cutting on the corrosion resistance and surface bioactivity of Ti6Al4V titanium alloy after finish turning. The obtained research results have practical significance. They can be used by engineers during the development of technological processes for medical devices made of Ti6Al4V alloy to obtain favorable functional properties of these devices.

In vitro tribological investigation and osseointegration assessment for metallic orthopedic bioimplant materials

Abstract This research study is aimed at finding a suitable uncoated metallic biomaterial based on its wear properties and osseointegration ability for orthopedic implants. In the present work, wear tests were carried out on uncoated metallic biomaterials such as Co-Cr-Mo, SS316L, Ti6Al4V and Titanium grade 2. The wear tests were performed to determine friction coefficient and wear loss in the presence of simulated body fluid having a common pH of 7.25 similar to human plasma. The wear resistance was found to be highest for Co-Cr-Mo material followed by SS316L, Ti6Al4V and Titanium grade 2 material. To grow an apatite layer, uncoated metallic substrates were immersed for two weeks in a simulated body fluid having ion concentration equivalent to human blood plasma. Adhesive bonding strength of the apatite layer formed on the different bioimplant substrates was evaluated under tensile stress. The worn metallic surfaces post wear tests and metallic substrates with apatite layer were analyzed using scanning electron micrographs. From the results it was found that uncoated Ti6Al4V material is more suitable for orthopedic implants as compared to other materials studied in this work.

Optimization of laser parameters for improved corrosion resistance of nitinol

ABSTRACT Nickel-Titanium (Nitinol) alloy is one of the shape memory alloys with potential applications in biomedical and aerospace industries. However, long-term deployment of nitinol-based alloys in fluid medium leads to corrosion. In an attempt to improve the corrosion resistance, electrochemical studies were performed on laser processed nitinol in the presence of simulated body fluid. Design of experiments technique of central composite design was used to formulate the five levels of the three laser processing parameters for surface texturing including average power, pulse frequency, and laser irradiation per unit area. The output responses such as corrosion potential, corrosion current, and corrosion rate were evaluated using response surface methodology. The linear and nonlinear interaction effects of the processing parameters on the output responses were analyzed. A decrease in the corrosion rate of three orders of magnitude was observed in laser processed nitinol in comparison to pristine nitinol.

Bioactivity measurement of commercially pure titanium processed by micro-electric discharge drilling

The surface modification is a pivotal step in the field of the biomedical implant in order to improve its biomedical characteristics. A number of methods can be adopted to improve surface characteristics like coating, evaporation, sputtering, and ion implantation. The surface of any material can also be improved by machining. In the present work, an electric discharge drilling (EDD) was used for the development of quality holes on any conductive material regardless of its hardness. In the present research, commercially pure titanium (CPTi) was drilled for the development of microhole using the EDD. The effect of microholes on the apatite formation and weight gain was determined. The apatite formation was measured in the presence of simulated body fluid (SBF) after 7, 14, and 21 days of immersion. The temperature and pH during the apatite formation were 37 °C and 7.4, respectively. It was found that after the development of microholes, the quantity of apatite formation increases. On the contrary side on the normal CPTi material (without drilling), an insignificant apatite formation was observed. However, after drilling, the elements of calcium and phosphate were observed ever after 4 days of immersion in SBF. The surface area of the apatite formation increases by 24% after the development of microholes. Scanning electron microscopy (SEM) revealed the microstructure of the drilled surface before and after the immersion of CPTi in SBF. In addition, it was observed that with the increase in the number of holes and immersion period, the apatite formation increases.

Substantial effect of silk fibroin reinforcement on properties of hydroxyapatite/silk fibroin nanocomposite for bone tissue engineering application

Nano-biocomposites that mimics bone’s extracellular matrix with hydroxyapatite as an inorganic and silk fibroin as organic phase for three different ratios via a simple in-situ co-precipitation method have been synthesized. The silk fibroin, a biodegradable polymer from cocoons of Bombyx mori silkworm were extracted by employing a chemical-free High-Temperature High-Pressure method as a degumming route. Then followed by the regeneration process which was done by using calcium chloride-formic acid solvent system to replace time-consuming, cost-effective traditional methods. The prepared composites were structurally analyzed using Fourier Transform Infra-Red spectroscopy (FTIR) and X-ray Diffraction (XRD) techniques. The morphology and the elemental composition of the nano-biocomposites were examined using Field Emission Scanning Electron Microscopy (FESEM) and Energy-dispersive X-ray Spectroscopy (EDX). The in-vitro bioactivity of the bio-composites namely, swelling ratio, biodegradation and biomineralization ability is monitored in the presence of Simulated Body Fluid (SBF). Our observation demonstrate that silk fibroin concentration influences the formation of hydroxyapatite.

Investigations of surface integrity, bio-activity and performance characteristics during wire-electrical discharge machining of Ti-6Al-7Nb biomedical alloy

In present research, Ti-6Al-7Nb was machined using wire-electrical discharge machining (WEDM). This material has high strength and the characteristics are similar to Ti-6Al-4V; but in the cytotoxic vanadium was replaced by niobium. As an application in biomedical, the bioactivity and surface characteristics of material should be high. Therefore, in present work the bioactivity and surface integrity of machined surface was investigated. The WEDM responses were optimized using a hybrid approach of Taguchi-Regression analysis and Modified Genetic Programming (TRMGP). Response characteristics were predicted at 95% of confidence interval for both the population and confirmation experiments. The empirical models for surface roughness (SR) and material removal rate (MRR) have been generated using regression analysis (RA) and solved by modified genetic programming. The input machining variables were servo voltage (SV), pulse off-time (Toff) and pulse on-time (Ton) for the machinability of Ti-6Al-7Nb. The experimental layout was designed as per the Taguchi based orthogonal array (OA). The predicted and experimental values for MRR are 7.3996 mm3 min−1 and 7.13 mm3 min−1, while that of SR are 13.32 μm and 13.21 μm respectively. The machined surface was checked for bioactivity in the presence of simulated body fluid (SBF). It was found that the surface machined by wire electric discharge machining enhances the bioactivity sites for the development of hydroxyapatite. The results of the present work confirm the suitability of hybrid approach of TRMGP to optimize WEDM response characteristics for enhancing machinability of Ti-6Al-7Nb for bio-medical applications.

Bioactive glass (45S5)-based 3D scaffolds coated with magnesium and zinc-loaded hydroxyapatite nanoparticles for tissue engineering applications

Bioactive glass (BG)-based scaffolds of 45S5 composition covered with hydroxyapatite nanoparticles loaded with Mg2+, Zn2+ and, both Mg2+ and Zn2+ ions, were developed and tested as materials for tissue engineering applications. The scaffolds were prepared by the foam replica technique and mono- and bi-metal loaded and unloaded hydroxyapatite nanoparticles (HA, Zn-HA, Mg-HA and Mg-Zn-HA) were obtained by an adaptation of the wet chemical deposition method. Coating of BG with these nanoparticles was performed by dip-coating to obtain HA-BG, Zn-HA-BG, Mg-HA-BG and Mg-Zn-HA-BG scaffolds.As predictor of the bone bonding ability of the produced scaffolds, in this study we investigated the formation of an apatite layer on the scaffold surfaces in the presence of simulated body fluid. The cytotoxicity and osteogenic properties of the materials in vitro was evaluated using human osteoblast-like MG-63 cell cultures. The mineralization assay following Kokubo’s protocol indicated that bi-metal loaded Mg-Zn-HA-BG scaffolds exhibited higher/faster bioactivity than mono-metal loaded scaffolds while mineralization of HA-BG, Zn-HA-BG and Mg-HA-BG was similar to that of uncoated scaffolds. Moreover, an increase of proliferation of MG-63 cells after 48 h and 7 days was measured by BrdU assays for Mg-Zn-HA-BG scaffolds. In agreement with these results, SEM images confirmed increased interaction between these scaffolds and cells, in comparison to that observed for mono-metal-loaded HA-coated scaffolds. Altogether, the obtained results suggest that nanocrystalline Mg-Zn-HA coatings enhance the biological performance of standard scaffolds of 45S5 BG composition. Thus these novel ion doped HA coated scaffolds are attractive systems for bone tissue engineering.

Tribo-corrosion characterization of NiTiCu alloy for bio-implant applications

In the current scenario of medical research, NiTi based smart alloys gaining importance due to the pioneer quality of biocompatibility, wear and corrosion resistance. In the present research, copper particles were blended with the nickel and titanium powder for 8 hours in high energy ball mill for uniform mixing. Specimens were fabricated using powder metallurgy at different compaction pressures. During the sintering process, the binder gets evaporated which makes it porous and suitable for biomedical implants. The testing was carried out to improve the corrosion and wear resistance of NiTi alloy under load-bearing biomedical applications. The addition of copper increases the wear and corrosion resistance of NiTi alloy. The experiments were conducted on pin-on-disk tribometer in the presence of simulated body fluid (SBF) at the temperature of 37 ± 1 °C. The test conditions were maintained according to the simulated hip joint. It was observed that the wear resistance of NiTi alloy increases slightly with the addition of copper particles up to certain percentage. The behaviour of the material changes after copper addition in the presence of SBF. Furthermore, the copper particles were blended with other particles to investigate the consequences on the tribological and corrosion characteristics of the developed materials. The corrosion rate increases when the copper contents were more than 5% due to decrease in the Ecorrosion (−0.19), but after increase the copper content from 5% an increase in Ecorrosion (−0.17) was observed. The copper content should be less than 5% to avoid pitting in the material; otherwise, it decreases the anti-pitting ability of NiTi alloy. The size of wear debris also decreases with the addition of copper up to 5%. After that, an increase in the size of wear debris was observed which makes it unsuitable for biomedical implants.

Mechanical, in-vitro biological and antimicrobial characterization as an evaluation protocol of a ceramic material based on alkaline activated metakaolin

The study aimed to correlate mechanical, physical and biological properties (in-vitro) of a ceramic material, based on alkaline activated metakaolin (MK) and CaCO3, to be used in the health sector. The designed materials reached compressive strengths in the range of 18 MPa to 29 MPa, after 7 days of curing, and porosity between 50 and 30%. The higher strength materials were subjected to a reactivity test for the formation of a layer of hydroxyapatite in the presence of simulated body fluid (SBF). By means of scanning electron microscopy, the in-situ growth of rounded crystals was identified, indicating the presence of elements such as Ca and P in its chemical composition. For the evaluation of the biological and anti-bacterial response, a system with the capacity to form a calcium phosphate layer on its surface was selected, with an increase in the pH value of the SBF solution and a compressive strength of at least 25 MPa. The results of the biological protocol showed that the material, due to its high pH, generates haemolysis or the rupture of red blood cells, indicating that the developed material needs to be modified in its chemical composition to decrease the high pH or to guarantee, by means of an additional processing stage, to decrease leaching of alkaline elements to the body fluid and thus not cause harmful effects on the human body. On the other hand, after being evaluated against several bacteria it was identified that the material had an inhibitory effect on Pseudomonas aeruginosa which makes suitable the material to be used in external applications.

Synthesis and Characterization of Nano Bioglass for the Application of Bone Tissue Engineering

In this paper, we are addressing the development of new composition (60%SiO2-30%CaO-10%P2O5) of biodegradable and biocompatible bioglass (nBG) nanoparticles. The bioglass nanoparticles have been fabricated by sol-gel method. To get functionalized bioglass nanoparticles, they were treated with lysozyme (1 mg/mL) for 48 h. Morphology of nanoparticles, such as structure, particle size, and surface topography were studied by TEM. Bioglass nanoparticles generate hydroxyapatite layer when nanoparticles treated with simulated body fluid (SBF) for 7 days. The presence of bioglass and hydroxyapatite phases confirmed by XRD. TEM images revealed irregular shaped with slightly agglomeration of nanoparticles in nanometer range (200 to 500 nm). The in-vitro biodegradation of nanoparticles was confirmed by weight loss in the presence of SBF. The cytotoxicity effects and cell proliferation of respective sample were investigated through MTT assay. BET results revealed average surface area (10.4 m2/g) of nanoparticles. The nano range of particles will provide better surface to volume ratio over micro or macro particles which makes them more effective so they are often able to react rapidly.

Characterization and bioactivity behavior of sol–gel derived bioactive vitroceramic from non-conventional precursors

The use of biomaterials has proven to be an excellent alternative in tissue regeneration due to the many possibilities they can offer. Bioactive glasses are a group of bioceramics that are being used in bone tissue engineering thanks to their biological properties, one of those being the bioactivity behavior. These bioactive glasses require a stabilization process by thermal treatments that partially crystallize the structure acquiring a vitroceramic state. In this study, sol–gel-derived bioactive vitroceramic was synthesized in a ternary system using non-conventional calcium and phosphate precursors in order to evaluate its bioactivity in the presence of simulated body fluid (SBF). The obtained bioactive vitroceramic was evaluated through XRD, FTIR, Raman and SEM to measure its chemical composition and morphology. The bioactivity test was carried out using cylindrical discs made with bioactive vitroceramic; those discs were analyzed in 7 and 14 days of exposition. The formed layer was studied with XRD, FTIR, SEM and EDX analysis. The results have shown that synthesized bioactive vitroceramic has similar composition and crystallinity of those reported in the same system indicating the appropriate use of different precursors. Likewise, the bioactivity behavior showed the formation of a non-crystalline hydroxyapatite layer on bioactive vitroceramic surface with a Ca/P ratio similar to that in bone, which means that the synthesized material can be used in bone tissue engineering.

Hydroxyapatite-chitosan biocomposites synthesized in the simulated body fluid and their drug loading studies

Hydroxyapatite (HAp) is a bioceramic applied in the biomedical areas, such as matrices for drug release control. Chitosan (CTS), a natural polymer, is another material has been widely investigated for its potential use in the drug delivery systems. In this study, the composites of HAp-CTS are produced in order to investigate their drug loading and release studies. First of all, HAp-CTS composites are produced in the presence of simulated body fluid (SBF). Analysis confirmed the structure of HAp-CTS composites. Secondly, composites are encapsulated with 5-Fluorouracil (5-FU). The weight ratio of CTS is varied to realize its effect on drug loading of 5-Fluorouracil, a cancer drug, for the ratios of 1:1, 1:2 and 1:4 of HAp-CTS. The weight ratio giving the greatest drug load efficiency is selected for the last step of the study. Crosslinking agent, glutaraldehyde, are changed from 0 to 5% on the selected sample, then, drug loading is examined again in various environment owing different pH. Furthermore, drug release studies are conducted. To understand the structure and morphology of the samples, XRD, FTIR, SEM and Uv-Spectrum are applied. It is observed that weight ratio of polymer and crosslinking agent can be manipulated to adjust drug loading. Release kinetics are shown the Fickian diffusion. This new produced material can be applicable for drug delivery.