Green synthesis of colloidal gold nanoparticles using latex from Hevea brasiliensis and evaluation of their in vitro cytotoxicity and genotoxicity

Latex extracted from Hevea brasiliensis tree has been used as a green alternative for preparing gold nanoparticles (Au NPs); however, no study evaluating the cytotoxic and genotoxic potential of Au NPs synthesised using H. brasiliensis has been published. The present study aimed to synthesise and characterise colloidal Au NPs using latex from H. brasiliensis and to evaluate their in vitro cytotoxicity and genotoxicity. Ideal conditions for the green synthesis of Au NPs were studied. In vitro cytotoxicity and genotoxicity of Au NPs in CHO‐K1 cells was also evaluated. Our findings indicated that the ideal synthesis conditions of pH, temperature, reduction time, and concentrations of latex and HAuCl₄ were 7.0, 85°C, 120 min, 3.3 mg/mL, and 5.0 mmol/L, respectively. LC50_{24 h} of Au NPs was 119.164 ± 5.31 μg/mL. Lowest concentration of Au NPs tested presented minimal cytotoxicity and genotoxicity. However, high concentrations of Au NPs promoted DNA damage and cell death via apoptosis. On the basis of these findings, the authors optimised the use of an aqueous solution of H. brasiliensis latex as a reducing/stabilising agent for the green synthesis of Au NPs. Low concentrations of these NPs are biocompatible in normal cell types, suggesting that these NPs may be used in biological applications.Inspec keywords: nanofabrication, biomedical materials, nanomedicine, colloids, pH, cellular biophysics, nanoparticles, gold, DNA, reduction (chemical), molecular biophysics, materials preparation, geneticsOther keywords: colloidal Au NPs, genotoxicity, green synthesis, in vitro cytotoxicity, Hevea brasiliensis, colloidal gold nanoparticle, latex concentrations, DNA damage, cell death, H. brasiliensis latex, normal cell types, Au     

Promising in vitro performances of a new nickel-free stainless steel

Stainless steel is a metallic alloy largely employed in orthopaedics. However, the presence in its composition of a high quantity of nickel, an agent known to trigger toxic and allergic responses, is cause for concern. In this study, we have investigated the in vitro biocompatibility of a new nickel-reduced stainless steel, namely Böhler P558, in comparison to the conventional stainless steel AISI 316L. The neutral red (NR) uptake and the amido black (AB) tests were performed on L929 fibroblasts and MG63 osteoblasts to assess the cytotoxicity, while cytogenetic effects were evaluated on CHOK1 cells by studying the frequency of Sister Chromatid Exchanges (SCE) and chromosomal aberrations. Ames test was used to detect the mutagenic activity. The expression of selected markers typical of differentiated osteoblasts, such as alkaline phosphatase activity (ALP), type I collagen (CICP) and osteocalcin (OC) production, were also monitored in MG63 cells cultured on the tested materials. Our results indicate the absence of significant cytotoxicity and genotoxicity for both test alloys. ALP, CICP and OC analyses confirmed that both materials support the expression of these phenotypic markers. Overall, these data show that this Ni-free alloy possesses good in vitro biocompatibility and could have a potential for orthopaedic applications.     

Biocompatibility studies of natural rubber latex from different tree clones and collection methods

Natural rubber latex (NRL) has several features that make it an excellent biomaterial to promote the growth and repair of tissues, skin and bones. Most of the research with NRL membranes uses a mixture of different clones and chemical preservatives in the collection process. In this study, we compared five clones that produce NRL, seeking to identify their differences in biocompatibility. The clones studied were RRIM 600, PB 235, GT1, PR 255 and IAN 873 commonly found in plantations in Brazil. We did also study the effect of ammonia used during latex collection. NRL membranes were prepared aseptically and sterilized. In the in vitro tests, the membranes remained in direct contact with mouse fibroblasts cells for three periods, 24, 48 and 72 h. In the in vivo tests, the membranes were implanted subcutaneously in rabbits. The results indicated the biocompatibility of the membranes obtained from all clones. Membranes from the clones RRIM 600 and IAN 873 induced greater cell proliferation, suggesting greater bioactivity. It was found that the membranes made from latex that was in contact with ammonia during collection, showed cytotoxic and genotoxic effects in cultures, as well as necrosis, and increased inflammatory cells in the rabbit’s tissues close to the implant.     

In vitro toxicity study of plant latex capped silver nanoparticles in human lung carcinoma cells

Organically modified silver nanoparticles were prepared by biosynthetic route induced by stem latex of a medicinally important plant, Euphorbia nivulia. The reduction and stabilization is assisted by certain peptides and terpenoids present within the latex. The aqueous formulation of latex capped silver nanoparticles (LAgNPs) being completely free of toxic chemicals can be directly used for administration/in vivo delivery of nanoparticles. The in vitro cytotoxicity evaluation of the latex capped nanoparticles was carried out using human lung carcinoma cells (A549) by MTT cell viability assay. Further, possible cytotoxic mechanisms were evaluated using various biomarkers for cytotoxicity and oxidative stress viz. extracellular lactate dehydrogenase (LDH) release, reactive oxygen species (ROS) generation, intracellular reduced glutathione (GSH), malondialdehyde (MDA), superoxide generation and acridine orange/ethedium bromide staining. It can be concluded from the present study that LAgNP formulation is toxic to A549 cells in a dose dependent manner. Thus plant latex solubilizes the AgNPs in water and acts as a biocompatible vehicle for transport of AgNPs to tumor/cancer cells.     

Biocompatibility evaluation of magnetosomes formed by Acidithiobacillus ferrooxidans

Magnetite nanocrystal has been extensively used in biomedical field. Currently, an interesting alternative to synthetic magnetic Fe₃O₄ nanoparticles, called magnetosome, has been found in magnetotactic bacteria. It has been reported that Acidithiobacillus ferrooxidans (At. ferrooxidans) has a potential to synthesize magnetosome. In this study, transmission electron microscope (TEM) was used to analyze the magnetite particles in At. ferrooxidans BY-3. The magnetosomes formed by this bacterium were isolated by a method combining ultracentrifugation and magnetic separation. Crystalline phase and surface functional group of the magnetosomes were investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), respectively. Biocompatibility of the magnetosomes was systematically evaluated at various concentrations (0.5, 1.0, 2.0 and 4.0 mg/ml). MTT test, hemolysis assay and Micronucleus Test were carried out to evaluate in vitro cytotoxicity, blood toxicity and genotoxicity of magnetosomes, respectively. Under these conditions, magnetosomes showed no cytotoxic, genotoxic and hemolytic effects up to 4.0 mg/ml indicating good biocompatibility of these biological nanoparticles. These revealed that the magnetosomes might have a potential for biotechnological and biomedical applications in the future.     

In vitro biocompatibility evaluation of silk-fibroin/polyurethane membrane with cultivation of HUVECs

In order to investigate the in vitro biocompatibility of a novel polyurethane （PU） membrane modified by incorporation of superfine silk-fibroin powder （SFP）, which was prepared for small-diameter vascular grafts, with the cultivation of human umbilical vein endothelial cells （HUVECs）, PU and SFP were mixed with the ratios of 9：1, 7：3, 5：5, 3：7 （PU：SFP） to make four composite materials. Unmodified PU and polytetrafluoroethylene （PTFE） were added as control groups. CCK-8 assay was used to evaluate the cytotoxicity of these biomaterials. Data were processed using SPSS, and P〈 0.05 was considered to be statistically significant. Adherence and spreading of HUVECs on the surface of specimens was observed using direct contact cultivation. The toxicity ratings of the novel composites were grade 0-1, which is in the acceptable range. In all the experimental groups except control, SFP/PU with ratio of 1：9 had the least cytotoxicity property, and more content of SFP in the composite showed no improvement of the biocompatibility. HUVECs strongly attached to and grew on the surface of the biomaterials, and proliferated rapidly. The proliferation ability increased with increased proportion of SFP; however the cell quantity on the surface of the materials decreased when the proportion of SFP was equal to or larger than that of PU in the composite. It is concluded that this novel material has excellent cellular affinity with no cytotoxicity to HUVECs. Adding SFP gives PU better biocompatibility, while further research on optimum blend ratios is still needed.     

Biocompatibility study of theophylline/chitosan/β-cyclodextrin microspheres as pulmonary delivery carriers

To evaluate the biocompatibility of the theophylline/chitosan/β-cyclodextrin microspheres, which has a potential application in pulmonary delivery system. The detection of LDH and protein in BALF was examined acute cell toxicity, hemolysis test was carried out to estimate blood toxicity; Micronucleus Test was reckoned to identify genotoxicity, MTT assay was used to evaluate in vitro cytotoxicity, and muscle implantation investigated the tissue biocompatibility. The results demonstrated that the total contents of protein and LDH in BALF were not significantly different from that of normal group. The experiments showed that the cytotoxicity was depended on the concentration and had no cytoxicity at low concentration and no hemolysis activity. The micronucleus frequency of MS B was 0.99‰, which showed no genotoxic effects either. The results of implantation showed that the microspheres had no effect on hemoglobin and no toxicity in the liver and kidney. The inflammations of muscle tissue were not significantly different from that of operative suture, therefore, the MS B possess high good biocompatibility and can be applied in pulmonary sustained release systems.     

In vitro studies of calcium phosphate silicate bone cements

A novel calcium phosphate silicate bone cement (CPSC) was synthesized in a process, in which nanocomposite forms in situ between calcium silicate hydrate (C–S–H) gel and hydroxyapatite (HAP). The cement powder consists of tricalcium silicate (C₃S) and calcium phosphate monobasic (CPM). During cement setting, C₃S hydrates to produce C–S–H and calcium hydroxide (CH); CPM reacts with the CH to precipitate HAP in situ within C–S–H. This process, largely removing CH from the set cement, enhances its biocompatibility and bioactivity. The testing results of cell culture confirmed that the biocompatibility of CPSC was improved as compared to pure C₃S. The results of XRD and SEM characterizations showed that CPSC paste induced formation of HAP layer after immersion in simulated body fluid for 7 days, suggesting that CPSC was bioactive in vitro. CPSC cement, which has good biocompatibility and low/no cytotoxicity, could be a promising candidate as biomedical cement.     

The chorioallantoic membrane of the chick embryo as a simple model for the study of the angiogenic and inflammatory response to biomaterials

Angiogenesis is essential in wound healing and a common feature in chronic inflammation which is crucially involved in the biological response to biomaterials. A useful system to evaluate the angiogenic activity and the inflammatory potency of various agents is the chorioallantoic membrane (CAM) of the chick embryo. Here we examined its response to different biomaterials. Smooth materials such as PVC or the polyurethane Tecoflex® either unmodified or modified by an OH- or N(CH₃) ₃ ⁺ -end group (HEMA or MAPTAC) inhibited angiogenesis and did not induce the formation of granulation tissue. The anti-angiogenic effects of PVC, Tecoflex® and its HEMA modification, however, were only seen at an early stage of development. In contrast, the MAPTAC modified Tecoflex>® inhibited angiogenesis over the whole time. Rough materials, e.g. filter paper or a collagen/elastin membrane, stimulated angiogenesis and induced the formation of inflammatory tissue. Histological analysis revealed that the filter material was homogeneously populated with cells consisiting mainly of macrophages, fibroblasts and endothelial cells. The collagen/elastin membrane was only partially infiltrated with cells. Among those also clusters of granulocytes were present pointing to an acute inflammatory process. These data show that the angiogenic activity and inflammatory response of biomaterials strongly depend on the chemical composition and the physical structure of the material. The CAM assay appears to be a useful tool for studying biocompatibility. © 2001 Kluwer Academic Publishers     

Evaluation on cytotoxicity and genotoxicity of the L-glutamic acid coated iron oxide nanoparticles

To evaluate the cytotoxicity and genotoxicity of L-glutamic acid (Glu) coated Fe2O3 nanoparticles (hereafter refer as Glu@MNPs) on Chinese Hamster Lung (CHL) cells using Trypan blue dye exclusion assay, Oxidative stress markers, Comet assay and micronucleus (MN) assay. Results showed a low cytotoxicity with an IC50 was 254.739 microg/ml 36 h post incubation period in CHL cells. Furthermore, Cell redox status is slightly disturbed: Glu@MNPs exposure cause reactive oxygen species production, glutathione depletion and inactivation of some antioxidant enzymes: glutathione reductase, superoxide dismutase, but not catalase. Moreover, no significant genotoxic response was observed in CHL cells over concentration ranges from 8 to 128 microg/mL for all exposure time periods. The results suggest that the Glu@MNPs show biocompatibility In Vitro.     

Preparation of graded zirconia–CaP composite and studies of its effects on rat osteoblast cells in vitro

Hydroxyapatite (HAP) has excellent biocompatibility and bone bonding ability, but it is mechanically weak and brittle. To overcome this problem, we prepared a graded composite with calcium phosphide (CaP, decomposed from HAP during sintering) coating on the surface of zirconia (ZrO₂) ceramics. The mechanical properties and microstructure characteristics were studied with various techniques. The biocompatibility of graded ZrO₂–CaP composite was examined with rat osteoblast cells (OB cells) in vitro. Its effects on the production of alkaline phosphatase (ALP), Interleukin-6 (IL-6) and Growth-transforming Factor-β (TGF-β) by the OB cells were measured. The results showed that the mean tensile strength of the graded ZrO₂–CaP composites was 17.8 MPa, the maximum bending strength was 1112.24 MPa, and K_IC was 7.3–11.4 MPa·m^1/2, indicating that the composite was physically strong for use as an implant material. The ALP activity, IL-6 and TGF-β concentrations of the graded composite treated OB cells were much higher than that of the pure ZrO₂ treated group. There was no significant difference in ALP activity, the IL-6 and TGF-β concentrations between the graded ZrO₂–CaP composite group and HAP. The cytotoxicity of the composite material to rat fibroblast cells was insignificant. The graded zirconia–CaP composite greatly facilitated the proliferation and differentiation of rat OB cells in vitro, demonstrating excellent biocompatibility.     

CAD/CAM scaffolds for bone tissue engineering: investigation of biocompatibility of selective laser melted lightweight titanium

The objective of the current in‐vitro study was to evaluate the biocompatibility of a new type of CAD/CAM scaffold for bone tissue engineering by using human cells. Porous lightweight titanium scaffolds and Bio‐Oss® scaffolds as well as their eluates were used for incubation with human osteoblasts, fibroblasts and osteosarcoma cells. The cell viability was assessed by using fluorescein diazo‐acetate propidium iodide staining. Cell proliferation and metabolism was examined by using MTT‐, WST‐Test and BrdU‐ELISA tests. Scanning electron microscope was used for investigation of the cell adhesion behaviour. The number of devitalised cells in all treatment groups did not significantly deviate from the control group. According to MTT and WST results, the number of metabolically active cells was decreased by the eluates of both test groups with a more pronounced impact of the eluate from Bio‐Oss®. The proliferation of the cells was inhibited by the addition of the eluates. Both scaffolds showed a partial surface coverage after 1 week and an extensive to complete coverage after 3 weeks. The CAD/CAM titanium scaffolds showed favourable biocompatibility compared to Bio‐Oss® scaffolds in vitro. The opportunity of a defect‐specific design and rapid prototyping by selective laser melting are relevant advantages in the field of bone tissue engineering and regenerative medicine.Inspec keywords: calcium compounds, scanning electron microscopy, adhesion, titanium, CAD/CAM, tissue engineering, bone, biomedical materials, cellular biophysics, biomechanics, laser materials processing, meltingOther keywords: bone tissue engineering, human cells, porous lightweight titanium scaffolds, human osteoblasts, osteosarcoma cells, cell viability, fluorescein diazo‐acetate propidium iodide staining, cell proliferation, MTT tests, WST‐Test, BrdU‐ELISA tests, cell adhesion, devitalised cells, metabolically active cells, biocompatibility, selective laser melting, CAD‐CAM scaffolds, cell metabolism, scanning electron microscopy, Ti     

Label‐free and dynamic monitoring of cytotoxicity to the blood–brain barrier cells treated with nanometre copper oxide

A cytotoxicity study was conducted with a primary culture of the nervous system cells, including brain microvascular endothelial cells (BMECs) and astrocytes, which are important components of the blood–brain barrier. The real‐time cell analysis (RTCA) was used to determine the cytotoxicity of copper‐oxide nanoparticles (CuO NPs). The IC₅₀ values of CuO NPs in astrocytes and BMECs were determined by the RTCA at different exposure times and were used as base values for further research. DNA damage after exposure to CuO NPs for 3 and 24 h was assessed using comet assay at the IC₅₀ obtained from RTCA. The onset time of cytotoxicity induced by CuO NPs was 2 and 2–4 h post‐exposure in BMECs and astrocytes, respectively. Furthermore, the degree of cytotoxicity induced by exposure to CuO NPs for 24–48 h in the BMECs and astrocytes was similar. Treatment with CuO NPs at 1/2*IC₅₀ and 1/5*IC₅₀ for 3 h induced genotoxicity in both cells as assessed by a measurement of DNA damage, although no cytotoxicity was observed. However, significant DNA damage was observed at all concentrations of CuO NPs used in this study, when the treatment time was 24 h.Inspec keywords: biochemistry, blood, brain, cellular biophysics, copper compounds, DNA, molecular biophysics, nanoparticles, toxicologyOther keywords: label‐free cytotoxicity monitoring, dynamic cytotoxicity monitoring, blood‐brain barrier cells, nervous system cells, brain microvascular endothelial cells, astrocytes, real‐time cell analysis, copper‐oxide nanoparticles, comet assay, genotoxicity, DNA damage measurement, time 24 h to 48 h, time 2 h to 4 h, CuO     

Biocompatibility enhancement of graphene oxide‐silver nanocomposite by functionalisation with polyvinylpyrrolidone

Several materials such as silver are used to enhance graphene oxide (GO) sheets antimicrobial activity. However, these toxic materials decrease its biocompatibility and hinder its usage in many biological applications. Therefore, there is an urgent need to develop nanocomposites that can preserve both the antimicrobial activity and biocompatibility simultaneously. This work highlights the importance of functionalisation of GO sheets using Polyvinylpyrrolidone (PVP) and decorating them with silver nanoparticles (AgNPs) in order to enhance their antimicrobial activity and biocompatibility at the same time. The structural and morphological characterisations were performed by UV‐Visible, Fourier transform infrared (FTIR), and Raman spectroscopic techniques, X‐ray diffraction (XRD), and high‐resolution transmission electron microscopy (HR‐TEM). The antimicrobial activities of the prepared samples against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans were studied. The cytotoxicity of prepared materials was tested against BJ1 normal skin fibroblasts. The results indicated that the decoration with AgNPs showed a significant increase in the antimicrobial activity of GO and FGO sheets, and functionalisation of GO sheets and GO‐Ag nanocomposite with PVP improved the cell viability about 40 and 35%, respectively.Inspec keywords: biomedical materials, nanocomposites, visible spectra, ultraviolet spectra, X‐ray diffraction, cellular biophysics, nanoparticles, Raman spectra, filled polymers, transmission electron microscopy, silver, microorganisms, antibacterial activity, nanomedicine, nanofabrication, graphene compounds, toxicology, Fourier transform infrared spectraOther keywords: graphene oxide‐silver nanocomposite, polyvinylpyrrolidone, toxic materials, biocompatibility, antimicrobial activity, morphological characterisations, structural characterisations, UV‐visible spectra, Fourier transform infrared spectra, Raman spectra, X‐ray diffraction, high‐resolution transmission electron microscopy, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, cytotoxicity, BJ1 normal skin fibroblasts, cell viability, CO‐Ag     

Study on the genotoxicity of HA/ZrO2 composite particles in vitro

To evaluate the genotoxicity of the HA/ZrO₂ composite particles by using the micronucleus test (MNT) in vitro. HA/ZrO₂ composite particles prepared by sintering at high temperature and pressure, that used powder of HA and ZrO₂ of different proportions, were compared with pure HA particles and pure ZrO₂ particles. The effect of the composite particles on cell proliferation of rabbit mesenchymal stem cells, and its the genotoxicity to rabbit mesenchymal stem cells were detected by MNT method. The MTT test showed that both pure HA particles and composite particles which contained HA promoted cell proliferation of rabbit mesenchymal stem cells, while pure ZrO₂ particles did not, and there was a significant difference (P < 0.05). The MNT test showed no significant difference between the HA group and the negative control group (P > 0.05), but a significant difference between the HA group and the positive control group (P < 0.05). The difference between the ZrO₂ group and the negative control group was significant (P < 0.01), while the difference between the ZrO₂ group and the positive control group was insignificant (P > 0.05). The genotoxicity of the HA/ZrO₂ composite particle increased with a higher proportion of ZrO₂ and an increase in the concentration of the composite, and the 30 wt.% HA/70% ZrO₂ composite with 200 μg/mL concentration showed significant genotoxicity (P < 0.01).     

Cytotoxicity study of some Ti alloys used as biomaterial

An implanted material is considered biocompatible, if adverse and uncontrollable reactions don't exist in the biological system. In this sense, biocompatibility tests made in the constituent materials are very important so that the implants have success. The in vitro cytotoxicity tests represent the initial phase of the process, and could be considered as a pre-selection of those materials. In vitro techniques using cell culture have become widely used in the evaluation of biomaterial cytotoxicity, which has contributed to their standardization and the substitution of in vivo tests. This paper shows a study of the in vitro cytotoxicity of two Ti based alloys, Ti–13Nb–13Zr and Ti–35Nb–7Zr–5Ta, in the as-received condition and after heat treated. The results show that the alloys presented no cytotoxic effects in the studied conditions.     

Ag/TiO2/bentonite nanocomposite for biological applications: Synthesis,characterization, antibacterial and cytotoxic investigations

Bentonite (bent) clay supported silver (Ag)/titanium dioxide (TiO₂) nanocomposite material was green synthesized by facile thermal decomposition method in the absence of reducing and precipitating agents. The samples were characterized by XRD, BET, HR-SEM with EDX mapping, TEM with SAED patterns, XPS, PSA, FT-IR, and UV–Vis DRS. XRD and EDX spectra showed peaks of Ag and TiO₂, confirming the formation of the Ag/TiO₂ nanoparticles in the composite. TEM revealed the uniform distribution of Ag/TiO₂ nanoparticles cluster on the surface of the bent with an average size of ～5 to 50 nm. The antibacterial activities of Na-bent, Ag, TiO₂, and Ag/TiO₂/bent nanocomposite samples were tested against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacteria by the well diffusion method. Furthermore, the cytotoxicity of Ag/TiO₂/bent nanocomposite material was determined by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Also, the succinate-dehydrogenase release showed the nontoxic nature of the nanocomposite at low concentrations. The cytotoxicity results of samples were evaluated using human embryonic kidney cell line (HEK 293) and have given excellent biocompatibility and cell proliferation in the in vitro studies.     

In vitro and in vivo studies on the biodegradable behavior and bone response of Mg69Zn27Ca4 metal glass for treatment of bone defect

In the present work, the biodegradable behavior, cytocompatibility and osteogenesis activity of a Mg₆₉Zn₂₇Ca₄ metal glass were investigated. Electrochemical test, immersion test, cytotoxicity test and histopathological evaluation were carried out. The results showed that there was a dense protective layer formed on the surface of Mg₆₉Zn₂₇Ca₄ metal glass which could inhibit the degradation process in the Hank’s solution. In vitro cytotoxicity test showed that Mg₆₉Zn₂₇Ca₄ metal glass had good biocompatibility. Histopathological evaluation showed that the degradation of Mg₆₉Zn₂₇Ca₄ metal glass could promote the new bone formation with no obvious inflammatory reactions. After 2 months implantation, the diameter of the bone defect was reduced from the original φ6 mm to φ3.35 ± 0.40 mm with the degradation of Mg₆₉Zn₂₇Ca₄ metal glass. Therefore, it can be concluded that Mg₆₉Zn₂₇Ca₄ glass has great potential to be used as bone substitutes.     

Fabrication of a novel micro-nano fibrous nonwoven scaffold with Antheraea assama silk fibroin for use in tissue engineering

The success of developing artificial organs by tissue engineering depends on scaffold properties and architecture. Here, we describe the fabrication of an Antheraea assama fibroin based novel micro-nano fibrous nonwoven scaffold. The morphological and chemical characterization was done by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) respectively, which demonstrated the formation of scaffold with micro-nano architecture. The biocompatibility was assessed in vitro by haemolysis and cytotoxicity assays, whereby the scaffold was found to be nontoxic and efficient in supporting cell adhesion and growth.     

Development of controlled strength-loss resorbable beta-tricalcium phosphate bioceramic structures

Controlling the strength-loss rate during biodegradation is a bottleneck in developing viable resorbable ceramic implants. Resorbable beta-tricalcium phosphate (β-TCP) bioceramic is known for its excellent biocompatibility. However, it exhibits poor sinterability and poor flexural strength. Here, we improved sintering behavior and biaxial flexural strength of β-TCP bioceramic without altering its biocompatibility by introducing multi-oxide sintering additives, in small quantities. These additives could also tailor the rate of resorption and hardness deterioration of β-TCP. A range of additives were prepared and introduced into β-TCP powder. Resultant powders were uniaxially pressed and sintered at 1250 °C, in air. Considerable improvement in densification (up to 33%) and biaxial flexural strength (up to 43%) were achieved. X-ray powder diffraction (XRD) analysis confirmed that the additives didn't alter the phase purity. In vitro cytotoxicity and biocompatibility analyses were performed using a prostate cancer cell-line. Results showed that the doped and pure β-TCP structures were non-toxic and biocompatible.