Papers by Keyword: In Vitro

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Authors: Qian Tang, Roger Brooks, Serena Best
Abstract: Hydroxyapatite and silicon-substituted hydroxyapatite powers were prepared in-house through a wet precipitation method and then vacuum plasma sprayed onto Ti-6Al-4V discs. Two plasma gun input powers were employed, 37 kW and 40 kW. All coatings were nearly phase pure, except small traces of impurities (TTCP, -TCP and CaO). Coatings prepared under the lower plasma gun input power had lower crystallinity. In vitro studies showed that human osteoblast-like cells attached and spread very well on all coated discs. Among the four kinds of discs, SiHAC37 was the most supportive to cell growth.
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Authors: W. Han, Yue Dan Wang, Y.F. Zheng
Abstract: Nano TiO2 material is an extensively used and adequately studied material and has a close contact with human in various fields, such as dope, dye, ceramic, cosmetic and medicine. Therefore, it’s very important to study the biocompatibility and biosafety of nano TiO2 materials. In the present study, various nano TiO2 materials with different dimension and crystal structures were confected to suspensions with varied concentrations and evaluated in cell model (mouse fibrocyte) after autoclaving sterilization. After 24h, 48h and 72h of cell culture experiments, MTT assay was used to examine the cell proliferation behavior and the flow cytometry was used to examine the cell apoptosis behavior. The present results of cell experiment showed that nano TiO2 materials had no effect on cell proliferation and apoptosis in a certain range of time and concentration. MTT assay indicated the relative cell proliferation rate in all nano TiO2 material groups were above 92% and the toxicity grade were 0 or 1 class.
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Authors: Maria Elisa Rodrigues Coimbra, Carlos Nelson Elias, Paulo Guilherme Coelho
Abstract: The objective of this study was to physico/chemically characterize a commercially available and a newly developed Bioglass and also to evaluate their degradation properties. Materials and Method: Two bioresorbable glasses were utilized, a bioglass synthesized at Chemical Engineering College (University of São Paulo, Lorena, São Paulo) (BG1), and the other bioglass utilized was Biogran (BG2) (3i Implant Innovations, Brazil). Particles size distribution histograms were developed for both materials, and then they were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) before and after immersion in simulated body fluid (SBF) for 30, 60, and 90 days. Results: The particle size distribution showed that the mean particle diameters at 10%, 50%, and 90% of the total volume were 17.65, 66.18, and 114.71 µm for BG1, and 354.54, 437.5, 525.00 µm for BG2. SEM images of BG1 showed that the as-received material had a rough surface and as the time of degradation elapsed, this surface became smooth. The images of BG2 showed that the as-received material also had a rough surface, and after immersion in SBF, the material’s crystalline content/morphology could be observed. The X-ray diffraction recorded that BG1 showed a silica peak, not seen at BG2. FTIR revealed that both bioglasses were of similar composition, except for the CO3-carbonate minor peak, present at the BG2 sample. Conclusions: 1. The particle size distribution showed a polydispersed pattern for both materials. 2. The material suffered degradation, and the decomposition increased as a function of immersion in SBF. 3. Both bioglasses had similar composition.
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Authors: Agnese Brangule, Ingus Skadins, Aigars Reinis, Kārlis Agris Gross, Juta Kroica
Abstract: The activity of antibacterial material is conventionally estimated by using an indirect method – a bacteria suspension is inoculated onto a surface, and then the bacteria are collected from the surface and examined as to whether they can form colonies on the agar plate. In the present study, the presence of bacteria was examined by direct detection. Our study is based on FTIR-PAS with an interferometer cantilever detector. Our work discusses the possibility of identifying and distinguishing the presence of different bacteria (Staphylococcus epidermidis and Pseudomonas aeruginosa) and the possibility to evaluate the crystallization processes on the pressed calcium phosphate surface.
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Authors: Nader Nezafati, F. Moztarzadeh, Masoud Mozafari
Abstract: Basic drawbacks of calcium phosphate cements (CPCs) are the brittleness and low strength behavior which prohibit their use in many stress-bearing locations, unsupported defects, or reconstruction of thin bones. Recently, to solve these problems, researchers investigated the incorporation of fibers into CPCs to improve their strength. In the present study, various amounts of a highly bioactive glass fiber were incorporated into calcium phosphate bone cement. The obtained results showed that the compressive strength of the set cements without any fibers optimally increased by further addition of the fiber phase. Also, both the work-of-fracture and elastic modulus of the cement were considerably increased after applying the fibers in the cement composition. Herein, with the aim of using the reinforced-CPC as appropriate bone filler, the prepared sample was evaluated in vitro using simulated body fluid (SBF) and osteoblast cells. The samples showed significant enhancement in bioactivity within few days of immersion in SBF solution. Also, in vitro experiments with osteoblast cells indicated an appropriate penetration of the cells, and also the continuous increase in cell aggregation on the samples during the incubation time demonstrated the ability of the reinforced-CPC to support cell growth. Therefore, we concluded that this filler and strong reinforced-CPC may be beneficial to be used as bone fillers in surgical sites that are not freely accessible by open surgery or when using minimally invasive techniques.
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Authors: Akhtar Jahan Siddiqa, Koel Chaudhury, Basudam Adhikari
Abstract: The present work focuses on the development of biodegradable PLGA nanoparticles (NPs) for controlled release of a breast cancer drug, letrozole. NPs of different drug-polymer ratio formulations (F1, F2, F3, F4) were fabricated using solvent evaporation technique. Physico-chemical characteristics of these NPs were assessed using dynamic light scattering (DLS) spectrophotometer. In-vitro drug release study was carried out over an extended period of 30 days at 37 °C in simulated physiological fluid. To evaluate the release kinetics, data was fitted to different models. NPs with various sizes and size distributions were obtained by altering the drug-polymer ratio. Zeta potential of PLGA and drug loaded NPs were found to be-29.4± 1.3 mV and-21.0±0.6 mV, respectively. The release kinetics of the drug from NPs was in good agreement with Korsmeyer-Peppas model, ensuring controlled release of the drug from the NPs. In-vitro release studies showed high correlation coefficient (R2 = 0.90) for formulation F2 and F3 up to 30 days. It is concluded that NPs with F2 and F3 formulations provide a controlled release of the incorporated drug and, therefore, hold promise to be investigated further in detail.
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Authors: E. Barros, J. Alvarenga, Gutemberg Alves, B. Canabarro, G.V.O. Fernandes, Antonella M. Rossi, J.M. Granjeiro, M. Calasans-Maia
Abstract: The objective of this study was to investigate the in vitro and in vivo biological responses to carbonate apatite (cHA) in comparison to hydroxyapatite (HA). Spheres (400<ø>500 μm) of both materials were synthesized under 5°C (cHA) and 90°C (HA) and not sintered. The in vitro cytocompatibility was determined by the XTT assay, according to ISO 10993-5:2009, after exposure of MC3T3-E1 cells to the materials extracts. Ethics Commission on Teaching and Research in Animals approved this project (CEPA/NAL 193/10) and, subsequently, the biomaterials were grafted in the subcutaneous tissues of mice (n=15). After 1 and 3 weeks, five animals of each group were killed for samples removal containing biomaterials and surrounding tissues for histological examination. Semi-serial (5-μm thick) sections were cut and stained with Hematoxylin and Eosin (HE) and the presence of inflammatory infiltrates and biomaterials resorption were evaluated. The experimental group of 3 weeks didn’t show the presence of spheres of both biomaterials and few spheres were observed after 1 week. Histological analysis showed the granulation tissue around the biomaterials with the presence of multinucleated giant cells. After 3 weeks it was observed the presence of fibrous tissue around biomaterials and few inflammatory cells. No signals of tissue necrosis were observed in both groups in all experimental studied periods. Nanostructured carbonate apatite spheres are cytocompatible, biocompatible and present initial biosorption on the subcutaneous comparable to stoichiometric HA, indicating its suitability for further studies on regenerative medicine.
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Authors: Agnese Pavlova, Aigars Reinis, Liga Berzina-Cimdina, Juta Kroica, Aleksandra Burlakova, Kristaps Rubenis
Abstract: Extrusion is a perspective forming technology for obtaining objects with certain profile, important for the TiO2 application as biomaterial. Extruded samples were calcinated at 1100 °C, thermally treated in different atmospheres: at 1450 °C in air and at 1300 °C in vacuum. An approach was made to examine the adhesion and colonization intensity of Staphylococcus epidermidis and Pseudomonas aeruginosa on TiO2 ceramic in vitro. It was found that Ps.aeruginosa demonstrated higher adhesion and colonization intensity as S.epidermidis and TiO2 samples treated in vacuum demonstrated higher attachment of microorganisms as TiO2 samples treated in air. It was supposed that surface charge promoted the bacterial adhesion on the vacuum treated samples.
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Authors: S. Loty, J.M. Sautier, C. Loty, M.T. Tan, D.C. Greenspan, N. Forest
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Authors: Hua'an Zhang, Lin Sun, Wei Wang, Xiao Jun Ma
Abstract: Fibrosis caused by the host response to long-term transplanted microcapsules and the limitation of traditional L929 cell model for biocompatibility testing inspire the development of an assay of biocompatibility based on macrophage behavior. In this paper, the human monocytic cell line THP-1 was utilized for biocompatibility evaluation of microcapsule materials. The cell viability and secretion of nitric oxide (NO) and cytokines served as index of biocompatibility were assayed. It was found that the evaluated microcapsule materials had no effect on the stimulation of NO and cytokines secretion, which meant that these materials were biocompatible. Furthermore, it suggests the THP-1 cell a convenient in vitro experimental model that might be useful for long-term predictions of material biocompatibility.
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