Evaluation of Cell-Viability, Intracellular Lipid-Component and Efficiency of Lipid-Extraction of Chlamydomonas reinhardtii Cells Treated by UV-C Irradiation Aiming to Use Cell Directly

Author(s):  
Nakanishi A ◽  
◽  
Ozawa N ◽  
Watanabe M ◽  
Sakihama Y ◽  
...  

Aim: We aimed finally to construct a system to utilize intracellular lipids of Chlamydomonas reinhardtii by direct cell-use. To realize the system, a system of simple cell-sterilization to avoid environmental contamination without degradation of intracellular lipids was required. Industrially, a simple collecting system of internal lipids was also required. Methods and results: C. reinhardtii cultured in a photo bioreactor under autotrophic condition was irradiated by UV-C. After the irradiation with different time to cells under different culturing conditions, those cells were evaluated for cell-viability by staining with neutral red, intracellular cell components and efficiency of lipid-extraction with GC/FID, respectively. By UV-C irradiation for 10 min, C. reinhardtii cells after N-depletion were sterilized. Additionally, although the cells were morphologically crumbled under an optical microscope, the contents and the components of intracellular lipids showed few differences. Conclusion: C. reinhardtii cells were efficiently sterilized by UV-C irradiation and few treated cells leaked the intracellular lipids, indicating that the lipids could not be simply collected by centrifuging direct cell collection. Significance and impact of study: In this study, the sterilized cells could gradually leak the intracellular contents, indicating the possibility of direct-use of the cells to utilize lipids produced by C. reinhardtii.

1996 ◽  
Vol 63 (1_suppl) ◽  
pp. 65-68
Author(s):  
S. De Angeli ◽  
A. Fandella ◽  
C. Gatto ◽  
S. Buoro ◽  
C. Favretti ◽  
...  

A study was carried out on the effect of stroma-epithelium interaction on cellular growth and morphology in co-coltures of U285 prostatic epithelial cells with human prostatic and esophageal stromal cells and with murine fibroblasts of the 3T3-J2 line. The proliferation rate was determined by growth tests of neutral red and kenacid blue. Morphological observations were made under optical microscope on the same cultures used for the growth tests. Results highlighted a marked reduction in cellular growth in the co-cultures compared to control cultures, as well as the tendency of the stromal and epithelial cells to re-organise themselves in pseudo-acinous structures.


1997 ◽  
Vol 16 (11) ◽  
pp. 636-644 ◽  
Author(s):  
Christopher D Lindsay ◽  
Joy L Hambrook ◽  
Alison F Lailey

1 The A549 cell line was used to assess the toxicity of sulphur mustard (HD), using gentian violet (GV) and neutral red (NR) dyes as indicators of cell viability. It was found that exposure to concentrations in excess of 40 ?M HD resulted in a rapid onset of toxicity. 2 The ability of monoisopropylglutathione ester (MIPE) to protect A549 cells against the effects of a 100 ?M challenge dose ofHD was determined using the NR and GV assays. It was found that MIPE (8 mM) could protect cells against the effects ofHD though MIPE had to be present at the time of HD challenge. Cultures protected with MIPE were two times more viable than HD exposed cells 48 h after HD challenge when using the GV and NR assays to assess viability. Observations by phase contrast microscopy of NR and GV stained cultures confirmed these findings. Addition of MIPE after previously exposing the A549 cultures to HD (for up to 5 min) maintained cell viability at 72% compared to 37% for unprotected cultures, after which time viability fell significantly so that at 10 min there was no difference in viability between the MIPE treated and untreated cultures. 3 Pretreating A549 cultures with MIPE for 1 h followed by its removal prior to HD challenge did not maintain cell viability. Treatment of cultures with HD for 1 h followed by addition of MIPE did not maintain the viability of the cultures, thus the window within which it was possible for MIPE to rescue cell cultures from the effects of HD was of short duration. 4 High performance liquid chromatography was used to determine the biochemical basis of the actions of MIPE. It was found that whilst intracellular levels of cysteine were increased up to 40-fold following treatment of A549 cell cultures with MIPE, levels of reduced glutathione did not rise. The lack of protection seen in cultures pretreated with MIPE for 1 h prior to HD exposure suggests that raising intracellular cysteine levels was not an effective strategy for protecting cells from the effects of HD. The protection observed is probably due to extra cellular inactivation of HD by MIPE.


2005 ◽  
Vol 284-286 ◽  
pp. 431-434 ◽  
Author(s):  
U. Lohbauer ◽  
G. Jell ◽  
Priya Saravanapavan ◽  
Julian R. Jones ◽  
Larry L. Hench

Bioactive gel-glasses, such as the silver-doped Ag-S70C30 glass, can be used to modify the inflammatory response in a local body compartment such as in acne lesions and in nonhealing dermal wounds. In this study, the cytotoxicity of soluble silver, calcium and silica ions on human epidermal keratinocytes was investigated by measurements of mitochondrial activity (MTT assay) and neutral red dye uptake (NR assay). Ag-S70C30 extracts were prepared by soaking glass powder in complete culture medium at concentrations of 1 mg/ml and 2 mg/ml (mg of glass powder per ml of culture medium). Silver concentrations for both concentrations of approximately 1 ppm were detected by inductive coupled plasma analysis (ICP). No negative effect on the cell viability was measured for an initial gel-glass concentration of 1 mg/ml and for the two shortest extraction times at a concentration of 2 mg/ml. Based on the results from MTT/ NR assays, a pH rise of approximately one unit had no negative effect on the NHEK-A cell viability. This preliminary study on keratinocyte viability merits future investigations on silver bioglass as a novel antimicrobial wound healing agent.


Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 76
Author(s):  
Orit Avior ◽  
Noa Ben Ghedalia-Peled ◽  
Tomer Ron ◽  
Jeremy Goldman ◽  
Razi Vago ◽  
...  

Due to the excellent biocompatibility of Zn and Zn-based alloys, researchers have shown great interest in developing biodegradable implants based on zinc. Furthermore, zinc is an essential component of many enzymes and proteins. The human body requires ~15 mg of Zn per day, and there is minimal concern for systemic toxicity from a small zinc-based cardiovascular implant, such as an arterial stent. However, biodegradable Zn-based implants have been shown to provoke local fibrous encapsulation reactions that may isolate the implant from its surrounding environment and interfere with implant function. The development of biodegradable implants made from Zn-Fe-Ca alloy was designed to overcome the problem of fibrous encapsulation. In a previous study made by the authors, the Zn-Fe-Ca system demonstrated a suitable corrosion rate that was higher than that of pure Zn and Zn-Fe alloy. The Zn-Fe-Ca system also showed adequate mechanical properties and a unique microstructure that contained a secondary Ca-reach phase. This has raised the promise that the tested alloy could serve as a biodegradable implant metal. The present study was conducted to further evaluate this promising Zn alloy. Here, we assessed the material’s corrosion performance in terms of cyclic potentiodynamic polarization analysis and stress corrosion behavior in terms of slow strain rate testing (SSRT). We also assessed the ability of cells to survive on the alloy surface by direct cell culture test. The results indicate that the alloy develops pitting corrosion, but not stress corrosion under phosphate-buffered saline (PBS) and air environment. The direct cell viability test demonstrates the successful adherence and growth of cells on the alloy surface.


2011 ◽  
Vol 493-494 ◽  
pp. 325-330 ◽  
Author(s):  
J.A. Cortês ◽  
Elena Mavropoulos ◽  
Moema Hausen ◽  
Alexandre Rossi ◽  
J.M. Granjeiro ◽  
...  

Cell adhesion, proliferation and differentiation are important specific parameters to be evaluated on biocompatibility studies of candidate biomaterials for clinical applications. Several different methodologies have been employed to study, both qualitative and quantitatively, the direct interactions of ceramic materials with cultured mammal and human cells. However, while quantitatively evaluating cell density, viability and metabolic responses to test materials, several methodological challenges may arise, either by impairing the use of some widely applied techniques, or by generating false or conflicting results. In this work, we tested the inherent interference of different representative calcium phosphate ceramic surfaces (stoichiometric dense and porous hydroxyapatite (HA) and cation-substituted apatite tablets) on different tests for quantitative evaluation of osteoblast adhesion and metabolism, either based on direct cell counting after trypsinization, colorimetric assays (XTT, Neutral Red and Crystal Violet) and fluorescence microscopy. Cell adhesion estimation after trypsinization was highly dependent on the time of treatment, and the group with the highest level of estimated adhesion was inverted from 5 to 20 minutes of exposition to trypsin. Both dense and porous HA samples presented high levels of background adsorption of the Crystal Violet dye, impairing cell detection. HA surfaces also were able to adsorb high levels of fluorescent dyes (DAPI and phalloidin-TRITC), generating backgrounds which, in the case of porous HA, impaired cell detection and counting by image processing software (Image Pro Plus 6.0). We conclude that the choice for the most suitable method for cell detection and estimation is highly dependent on very specific characteristics of the studied material, and methodological adaptations on well established protocols must always be carefully taken on consideration.


2015 ◽  
Vol 10 (2) ◽  
pp. 443
Author(s):  
Fiaz Alam ◽  
Qazi Najam us Saqib ◽  
Abdul Waheed

<p>This study was conducted to evaluate <em>Gaultheria trichophylla</em> crude extract and respective saponins fraction against human breast cancer cell lines. In MTT assay, cell viability was inhibited by <em>G. trichophylla</em> crude extract (500 µg/mL) and saponins (200 µg/mL) in a dose dependent manner with maximum inhibition of (82% and 85%) and (71% and 42%) against MCF-7 and MDA MB-468, respectively. In neutral red uptake assay, the cell viability was inhibited by crude extract and saponins (100 µg/mL) in a similar manner with maximum inhibitions of (96% and 93%) and (87% and 61%) against MCF-7 and MDA MB-468, respectively, with respect to 91% and 93% inhibition by actinomycin-D (4 µM). The DAPI (4',6-diamidino-2-phenylindole) (10 µg/mL) staining of MCF-7 cells treated with crude saponins showed shrunken nuclei with apparent nuclear fragmentation indicating apoptosis and in contrast, MDA MB-468 showed necrosis mode of cell death. The study exhibited that the <em>G. trichophylla</em> provides new evidences to further explore this plant for the novel targets in anticancer drug development.</p>


1999 ◽  
Vol 65 (7) ◽  
pp. 3229-3232 ◽  
Author(s):  
Audrey Caro ◽  
Patrice Got ◽  
Jean Lesne ◽  
Sylvie Binard ◽  
Bernard Baleux

ABSTRACT Maintenance of pathogenicity of viable but nonculturableSalmonella typhimurium cells experimentally stressed with UV-C and seawater, was investigated relative to the viability level of the cellular population. Pathogenicity, tested in a mouse model, was lost concomitantly with culturability, whereas cell viability remained undamaged, as determined by respiratory activity and cytoplasmic membrane and genomic integrities.


2017 ◽  
Vol 753 ◽  
pp. 259-263
Author(s):  
Atsdawut Areesirisuk ◽  
Chiu Hsia Chiu ◽  
Tsair Bor Yen ◽  
Jia Hsin Guo

In this study, intracellular lipids of a novel oleaginous biomass of P. parantarctica were converted to biodiesel directly using simple acid catalyst methanolysis. The optimum condition of this method was investigated. Under optimum conditions (0.1 M H2SO4, 10 h reaction time, 65°C reaction temperature, and 1:20 (w/v) biomass-to-methanol ratio), the yield of crude biodiesel was 93.18 ± 2.09% based on total cellular lipids. The composition of crude biodiesel was C16:C18 fatty acid methyl esters (FAMEs) for 91.91%. Especially, the C18:1 methyl ester was the main FAME (47.10%). In addition, the result showed that this technique could produce the microbial biodiesel from biomass containing high free fatty acids (FFAs) without soap formation. The predicted cetane number and kinematic viscosity of biodiesel were characterized according to ASTM D6751 and EN 14214 standards. Our results indicated that this process produces a good quality biodiesel. Moreover, it can decrease the manufacturing costs of microbial biodiesel production from oleaginous yeast biomass without cell disruption and lipid extraction.


Sign in / Sign up

Export Citation Format

Share Document