Kaolinite‐based hybrid material from interlayer grafting of 1‐(2‐hydroxyethyl)piperazine and application to the sensitive voltammetric detection of lead

2021 ◽  
Author(s):  
Guy Bertrand NGASSA PIEGANG ◽  
Jonathan FAFARD ◽  
Ignas TONLE
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.


2019 ◽  
Vol 15 (5) ◽  
pp. 567-574
Author(s):  
Huck Jun Hong ◽  
Suw Young Ly

Background: Tetrodotoxin (TTX) is a biosynthesized neurotoxin that exhibits powerful anticancer and analgesic abilities by inhibiting voltage-gated sodium channels that are crucial for cancer metastasis and pain delivery. However, for the toxin’s future medical applications to come true, accurate, inexpensive, and real-time in vivo detection of TTX remains as a fundamental step. Methods: In this study, highly purified TTX extracted from organs of Takifugu rubripes was injected and detected in vivo of mouse organs (liver, heart, and intestines) using Cyclic Voltammetry (CV) and Square Wave Anodic Stripping Voltammetry (SWASV) for the first time. In vivo detection of TTX was performed with auxiliary, reference, and working herring sperm DNA-immobilized carbon nanotube sensor systems. Results: DNA-immobilization and optimization of amplitude (V), stripping time (sec), increment (mV), and frequency (Hz) parameters for utilized sensors amplified detected peak currents, while highly sensitive in vivo detection limits, 3.43 µg L-1 for CV and 1.21 µg L-1 for SWASV, were attained. Developed sensors herein were confirmed to be more sensitive and selective than conventional graphite rodelectrodes modified likewise. A linear relationship was observed between injected TTX concentration and anodic spike peak height. Microscopic examination displayed coagulation and abnormalities in mouse organs, confirming the powerful neurotoxicity of extracted TTX. Conclusion: These results established the diagnostic measures for TTX detection regarding in vivo application of neurotoxin-deviated anticancer agents and analgesics, as well as TTX from food poisoning and environmental contamination.


1981 ◽  
Vol 46 (8) ◽  
pp. 1800-1807 ◽  
Author(s):  
Zdeněk Vejdělek ◽  
Marie Bartošová ◽  
Miroslav Protiva

4-Chloromethyl-s-hydrindacene (VIIa) was transformed via the malonic acid derivatives VIIIa and IXa to the acid Xb which afforded in four steps the homological acid Xc. Reactions of chlorides of both acids (XIbc ) with dimethylamine, 1-methylpiperazine and 1-(2-hydroxyethyl)piperazine led to the amides XIIbc-XIVbc which were reduced with lithium aluminium hydride to the title compounds IVcd-VIcd. The amines obtained show central neuroleptic effects only in subtoxic doses; they are also potent local anaesthetics and have significant spasmolytic activity of the neurotropic as well as musculotropic type.


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