scholarly journals Monocytes-based in vitro assay for a preliminary biocompatibility assessment of blood-contacting devices

2019 ◽  
Vol 17 ◽  
pp. 205873921882047
Author(s):  
Claudia Gemelli ◽  
Alexis Grande ◽  
Sergio Ferrari ◽  
Aldo Tomasi ◽  
Aurora Cuoghi

The biological evaluation of biomaterials is currently defined by the ISO-10993 norm in which parts four and five are dedicated to emo-compatibility and cell toxicity, respectively. Our study will provide a novel in vitro experimental approach for the biocompatibility assessment of biomaterials or medical devices using human primary monocytes as cellular model. In these new settings, human monocytes are exposed to a medium containing the extractable compounds derived from materials or devices; subsequently, cell toxicity and pro-inflammatory effects are analysed through MTT assay, flow cytometry and enzyme-linked immunosorbent assay (ELISA) methodologies. These experimental procedures offer the advantage to use a human and primary cell context belonging to the immune system, in order to accurately predict the nature of blood/device interaction occurring during a clinical application. To validate the reliability of this method, we also reported a comparative study between two different membranes showing a different level of biocompatibility. On the bases of these data, it is possible to state that this new experimental model represents a good approach to investigate the effects induced by a biomaterial on cell death and inflammation using human, primary monocytes.

1992 ◽  
Vol 3 (2) ◽  
pp. 79-84 ◽  
Author(s):  
C. McGuigan ◽  
B. C. N. M. Jones ◽  
S. M. Tollerfield ◽  
P. A. Riley

Novel phosphate triester derivatives of the antiviral drug araA and the anti-leukaemic agent araC have been prepared as membrane-soluble pro-drugs of the bio-active free nucleotides. In particular, novel trichloro- and trifluoroethyl phosphates have been prepared using phosphorochloridate chemistry, and are fully characterized. An in vitro assay indicates inhibition, by each of the compounds, of thymidine incor-portion by mammalian epithelial cells. It is notable that the trichloroethyl derivative is most active in each case, and in the case of araC its activity appears to exceed that of the parent nucleoside.


1968 ◽  
Vol 20 (03/04) ◽  
pp. 384-396 ◽  
Author(s):  
G Zbinden ◽  
S Tomlin

SummaryAn in vitro system is described in which adhesion of blood platelets to washed and tannic acid-treated red cells was assayed quantitatively by microscopic observation. ADP, epinephrine and TAME produced a reversible increase in platelet adhesiveness which was antagonized by AMP. With Evans blue, polyanetholsulfonate, phthalanilide NSC 38280, thrombin and heparin at concentrations above 1-4 u/ml the increase was irreversible. The ADP-induced increase in adhesiveness was inhibited by sodium citrate, EDTA, AMP, ATP and N-ethylmaleimide. EDTA, AMP and the SH-blocker N-ethylmaleimide also reduced spontaneous platelet adhesion to red cells. No significant effects were observed with adenosine, phenprocoumon, 5-HT, phthalanilide NSC 57155, various estrogens, progestogens and fatty acids, acetylsalicylic acid and similarly acting agents, hydroxylamine, glucose and KCN. The method may be useful for the screening of thrombogenic and antithrombotic properties of drugs.


Author(s):  
Muhammad Arfat Yameen ◽  
Amir Zeb ◽  
Raza E Mustafa ◽  
Sana Mushtaq ◽  
Nargis Aman ◽  
...  

Background: Incoherent use of antibiotics has led toward resistance in MRSA, which is becoming multidrugresistant with high rate of virulence in the community and hospital settings. Objective: Synergistic anti-MRSA activity was investigated in this study for hybrid material composite spheres of amoxicillin, Ag nanoparticles and chitosan which were prepared by one-step synthesis method and various characterizations were performed. Methods: Antimicrobial-susceptibility assay on MRSA was achieved by disc diffusion and agar dilution techniques while agar well diffusion was used for hybrid composite spheres. The in vitro and cytotoxicity studies was done by skin abrasion mouse model and MTT assay on RD cell respectively. Results: All isolates were resistant with the tested antibiotics except vancomycin. MIC against MRSA showed high resistance with amoxicillin from 4 to 128 mg L-1. The mean diameter of chitosan spheres and Ag nanoparticles was 02 mm and 277 nm respectively. Morphology of spheres was uneven, varied, porous and irregular in SEM and Ag nanoparticles presence and formation was also seen in micrograph. No substantial interface among drug, nanoparticles and polymer was found in XRD and IR showed characteristic peaks of all compound in the formulation. The in vitro assay showed augmented anti-MRSA activity with amoxicillin loaded hybrid composite spheres (22-29 mm). A significant reduction in microbial burden (~6.5 log10 CFU ml-1) was seen in vivo with loaded hybrid composite spheres formulation. The MTT assay indicated no potential cytotoxicity with hybrid composite spheres. Conclusion: Synergistic effect, amoxicillin, new hybrid formulation, anti-MRSA activity, composite spheres. nanoparticles.


2021 ◽  
pp. 1-9
Author(s):  
Anita Virtanen ◽  
Outi Huttala ◽  
Kati Tihtonen ◽  
Tarja Toimela ◽  
Tuula Heinonen ◽  
...  

<b><i>Objective:</i></b> To determine the direct effect of pravastatin on angiogenesis and to study the interaction between pravastatin and maternal sera from women with early- or late-onset pre-eclampsia (PE), intrauterine growth restriction, or healthy pregnancy. <b><i>Methods:</i></b> We collected 5 maternal serum samples from each group. The effect of pravastatin on angiogenesis was assessed with and without maternal sera by quantifying tubule formation in a human-based in vitro assay. Pravastatin was added at 20, 1,000, and 8,000 ng/mL concentrations. Concentrations of angiogenic and inflammatory biomarkers in serum and in test medium after supplementation of serum alone and with pravastatin (1,000 ng/mL) were measured. <b><i>Results:</i></b> Therapeutic concentration of pravastatin (20 ng/mL) did not have significant direct effect on angiogenesis, but the highest concentrations inhibited angiogenesis. Pravastatin did not change the levels of biomarkers in the test media. There were no changes in angiogenesis when therapeutic dose of pravastatin was added with maternal sera, but there was a trend to wide individual variation towards enhanced angiogenesis, particularly in the early-onset PE group. <b><i>Conclusions:</i></b> At therapeutic concentration, pravastatin alone or with maternal sera has no significant effect on angiogenesis, but at high concentrations the effect seems to be anti-angiogenic estimated by in vitro assay.


Lab on a Chip ◽  
2021 ◽  
Author(s):  
YUHAO QIANG ◽  
Jia Liu ◽  
Ming Dao ◽  
E Du

Red blood cells (RBCs) are subjected to recurrent changes in shear stress and oxygen tension during blood circulation. The cyclic shear stress has been identified as an important factor that...


1981 ◽  
Vol 36 (1-2) ◽  
pp. 30-34 ◽  
Author(s):  
Rainer Sütfeld ◽  
Rolf Wiermann

Abstract Chalcone synthase was isolated from both anthers of Tulipa cv. “Apeldoorn” and petals of Cosmos sulphureus Cav. After certain prepurification steps, the enzymes were further purified using gel chromatography on Sephadex G-200 followed by repeated hydroxylapatite absorption chromatography. Both the enzymes showed the same chromatographic properties. After gel chromatography as well as after the first hydroxylapatite fractionation, the reaction products appeared as flavanones. However, after the second hydroxylapatite step, production of chalcones was observed. Like the enzyme from tulip anthers, the synthase from Cosmos petals produced the correspondingly substituted chalcones when p-coumaroyl-CoA, caffeoyl-CoA and feruloyl-CoA, respectively, were used as substractes. In both the cases, the ratios of the different chalcones produced were found to be about the same. The appearance of chalcone synthesis in this in vitro assay is caused by the complete elimination of chalcone isomerase in the purification procedure. The importance of the isomerase for flavonoid biosynthesis, particularly in plant systems which are accumulating chalcones, is discussed.


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