Papers by Keyword: Cytotoxicity

Abstract: The petroleum ether, chloroform, ethyl acetate, n-hexane and aqueous successive extracts from the stems of Actinidia macrosperma C. F. Liang have been screened for antibacterial and antifungal activities in vitro using the disc diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC). General toxicity of these extracts has also been assessed by brine shrimp lethality assay. The chloroform extract exhibited the most significant antimicrobial (MIC in the range of 60–500μg/ml, MBC in the range of 150–1000μg/ml, MFC in the range of 170–600μg/ml) and cytotoxic activities (LC₅₀=16.82μg/ml at 24 hours).

Abstract: A novel functional material was fabricated by combining levofloxacin microspheres with viscose nonwoven fabrics. The complex microspheres were made by w/o emulsion crosslinking technique. The morphologies of both microspheres and fabric composite were investigated by SEM. The drug release property was evaluated by UV. The antibacterial activity and cytotoxicity were tested by spread plate and cell culture method. The results showed that the microspheres had spherical shape and could be embedded into the viscose fabrics. The levofloxacin was released gradually within 168 hours and its release kinetics corresponded to diffusion-relaxation model. In addition, the antibacterial activity of the fabric was increased with prolonged drug releasing time and the complex fabrics had no obvious cytotoxicity. The functional material has great potential to be used as a wound dressing with antibacterial property.

Abstract: Hydroxyapatite (HAP) and tricalcium phosphate (TCP) nanoparticles (NPs) are in current use covering a wide range of medical applications, hence, it is indispensable to study the potential side effect acting on living organism, and to figure out the biocompatibility evaluation model of nanoparticles for standardization and methodology. In the present study, HAP and TCP NPs were selected and their diameters were within 30-80nm. Cytotoxicity in vitro was analyzed by agar overlay and direct contact exposure test was conducted to evaluate potential toxicity to SD rat macrophages, and hemolysis test of NPs was performed in compliance with ISO 10993-12 guidelines. The results showed that both HAP and TCP NPs could inhibit proliferation of macrophages when their concentration was reached to 20 µg/ml, and the extent of haemolysis would be increased more than 5% while 1000µg/ml NPs were contacted with rabbit blood cells. Furthermore, TCP NPs could induce obvious hemolysis reaction and inhibit proliferation of macrophages compared with group of HAP NPs at the same concentration.

Abstract: An application of calcium phosphates is as bone cements, among which the system based on alpha-tricalcium phosphate (α-TCP) exhibits excellent properties. The aim of this study is to analyze pH evolution and cytotoxicity of α-TCP cement with three different additives. Changes on the pH were measured at intervals of 12h during seven days. But initial measurements were executed at each 15 minutes. Indirect cytotoxicity test was performed according to ISO (10993-5, 1992) employing CHO-k1 cells and RPMI 1640 as culture medium. It was used a colorimetric method which uses the tetrazolium compound. The additives used on the liquid phase were disodium hydrogen phosphate (Na₂HPO₄) and/or citric acid (C₆H₈O₇) and/or tannic acid (C₇₆H₅₂O₄₆). The results indicate that the cement without additives does not have requirements to be applied like bone cement, while the other cements composition exhibit different responses in the pH and the cytotoxicity test. In conclusion, due to the presence of additives it was possible to control pH evolution during setting and cytotoxic response. However, further investigation is necessary in order to determine the influence of these additives, mainly tannic acid, on the in vivo behavior of these bone cements.

Abstract: Carbonated apatite (CHA) is commonly considered a promising synthetic material for biomedical applications in orthopedic and dental surgery due to its biocompatibility, bioresorption and bioactivity. CHA5, CHA37 and CHA90 powders were synthesized from wet method and the DRX patterns showed that the crystallinity and particle size of CHA samples increased proportionally with the synthesis temperature. Powder extracts medium were obtained from each sample to interact with MC3T3-E1 osteoblastics cells. It was evaluated morphology, citotoxicity, pH and Ca²⁺ concentration. Citotoxicity assays showed high metabolic activity on all samples when compared to control. The polygonal shaped and the confluent monolayer observed in control cells progressively changed according to the crystallinity increase of samples. Cells under mitosis and spindle-like shaped where the main alterations observed. In addition the cell viability could be sensitive to the acid reactivity and crystallinity of carbonated apatite samples.

Abstract: In situ viscous mass foaming with ammonium bicarbonate (NH₄HCO₃) as foaming agent was used for the preparation of porous hydroxyapatite ceramics. Three different particle fractions (100-300 μm, 300-500 μm, 500-1000 μm) of NH₄HCO₃ were used in order to evaluate the particle size effect on the ceramic microstructure. Foamed and dried green bodies were sintered at 1150°C. The porosity and microstructure of ceramics were determined with Archimedes method and scanning electron microscopy. As the NH₄HCO₃ particle fraction was decrease from 100-300 μm to 500-1000 μm, the open porosity increased from 42 to 54 %. In situ viscous mass foaming leads to the interconnected pore channels with wide pore size range (10-600 μm). In the present work cytotoxicity of obtained porous HA ceramics and fibroblast cell viability was investigated.

Abstract: The research of obtained bioglasses in the form of silver-containing powders were presented in this paper. The research conducted in order to determine antimicrobial activity under in vitro conditions of bioglasses. The results confirmed that these bioglasses Z-5, Z-8 and B-I inhibit the growth of most micro-organisms during the tested period and could be used in surgical treatment of the most advanced parodontium illnesses.

Abstract: The failure of organs and tissues caused by trauma and other injuries is one of the most costly of human health problems. It is estimated that 1.6 million people experience work limitations caused by osteoarthritis and related disorders, representing 8.3% of all main conditions. Joint injuries frequently lead to progressive joint degeneration and post-traumatic osteoarthritis. Articular cartilage has only a limited capacity for self-healing, mainly due to the fact that it is avascular; and once seriously damaged, articular cartilage lesions will not regenerate. There is strong evidence that cartilage lesions may lead to osteoarthritis when left untreated. Numerous animal experiments and clinical studies have shown that early biological reconstruction of circumscribed cartilage defects in the knee is superior to conservative or delayed surgical treatment. Tissue engineering has shown promising therapeutic strategies for repair or regeneration of damaged tissues. Currently, ceramic based and polymeric scaffolds have been developed to bring about the restoration of tissue functions. The bioceramics associated with water-soluble polymers have been developed as substitutes for various orthopedic applications. The objectives of this work are the processing and characterization of a composite of carboxymethylcellulose (CMC) and biphasic calcium phosphate (Biphasic Calcium Phosphate - BCP) in the form of a hydrogel, and a study of its cytotoxicity (in vitro), aimed at its application as an injectable biomaterial in order to repair the extracellular matrix of articular cartilage. The CMC and BCP were characterized by Fourier Transform Infrared Spectrometry (FTIR) and X-Ray Diffraction (XRD), X-ray fluorescence (XRF), respectively, and scanning electron microscopy (SEM) of powders and the composite. To evaluate the biological effect of the composite hydrogel, tests of cytotoxicity (MTT) and rheological tests under real conditions of use were performed. The composite of carboxymethylcellulose (CMC) and bioceramics (biphasic calcium phosphate-BCP) in the form of hydrogel showed an adequate injectability in the conditions studied, and a non-toxic response, presenting potential for use as fillers or to stimulate the healing of cartilage defects in the extracellular matrix of articular cartilage.

Abstract: This work describes the mixed Cu-La-Ce nanocomplexes materials were synthesized by coprecipitation approach with aqueous solutions of copper nitrate, lanthanum nitrate and cerium nitrate. The nanocomplexes materials were characterized by TEM, with a particle size around nanoscale particle sizes (~50 nm) with high dispersion phenomena. Further, cell cytotoxicity and the percentage cell survival was determined by using 3-(4,5-dimethylthiazol-2-yl)-5 (3-carboxymethoxyphenol)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay on human fetal lung tissue cell (MRC-5). The experimental results show that the Cu-La-Ce nanocomplexes materials only minor cause cytotoxicity effect in cultured human cells.

Abstract: Copper oxide nanoparticles (CuO NPs) are used in antimicrobial preparations, heat transfer fluids, semi-conductors or intrauterine contraceptive devices. Nanoparticles with unique magnetic, luminescent, and catalytic properties are being engineered for numerous biomedical applications, including imaging, diagnostics and therapy. However, potentially harmful interactions can occur between nanoparticles and living systems, including humans. The present study was aimed to assess the cytotoxicity of CuO NPs in human alveolar epithelial cell line (A549). A reduction in cell viability as a function of NP concentration for 24h was observed. CuO NPs were also found to induce oxidative stress in cells indicated by generation of H₂O₂. Our data demonstrates that CuO NPs even at low concentrations lead to cell membrane damage in human epidermal cells which may be mediated through lipid peroxidation and oxidative stress, however, induced little effect to Mitochondria. Hence, caution should be taken in their widely use as well as while handling.