scholarly journals In Vitro Corrosion Behavior of Biodegradable Iron Foams with Polymeric Coating

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 184 ◽  
Author(s):  
Radka Gorejová ◽  
Renáta Oriňaková ◽  
Zuzana Orságová Králová ◽  
Matej Baláž ◽  
Miriam Kupková ◽  
...  

Research in the field of biodegradable metallic scaffolds has advanced during the last decades. Resorbable implants based on iron have become an attractive alternative to the temporary devices made of inert metals. Overcoming an insufficient corrosion rate of pure iron, though, still remains a problem. In our work, we have prepared iron foams and coated them with three different concentrations of polyethyleneimine (PEI) to increase their corrosion rates. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), Fourier-transform infrared spectroscopy (FT-IR), and Raman spectroscopy were used for characterization of the polymer coating. The corrosion behavior of the powder-metallurgically prepared samples was evaluated electrochemically using an anodic polarization method. A 12 weeks long in vitro degradation study in Hanks’ solution at 37 °C was also performed. Surface morphology, corrosion behavior, and degradation rates of the open-cell foams were studied and discussed. The use of PEI coating led to an increase in the corrosion rates of the cellular material. The sample with the highest concentration of PEI film showed the most rapid corrosion in the environment of simulated body fluids.

1986 ◽  
Vol 66 (2) ◽  
pp. 547-551 ◽  
Author(s):  
H. KUDO ◽  
K.-J. CHENG ◽  
W. MAJAK ◽  
J. W. HALL ◽  
T. ARAI ◽  
...  

The microbiota in the esophageal sac of voles fed either cubed alfalfa hay or concentrate pellets were assayed to determine their capacity to anaerobically degrade mimosine in vitro. Differences (P < 0.01) were found between the two diets during the growth phase. The sac contents of voles fed concentrate pellets degraded mimosine and 3-hydroxy-4-(1H)-pyridone (DHP) rapidly, but inocula from voles fed cubed alfalfa hay only hydrolyzed mimosine to DHP. Degradation of the pyridine ring occurred at the early stage of incubation, concurrently with microbial growth. Thereafter, degradation rates appear to have been almost negligible and very similar for both diets. These results agree with previous data obtained with ruminal microorganisms, where highly active inocula were also associated with animals on concentrate diets. Key words: Detoxification, hydrolysis, esophageal sac, mimosine, 3-hydroxy-4- (1H)-pyridone, voles


NANO ◽  
2013 ◽  
Vol 08 (04) ◽  
pp. 1350042 ◽  
Author(s):  
JING WANG ◽  
LI GUO ◽  
LI FANG MA

In this paper, we firstly synthesized glycyrrhetinic acid-modified double amino-terminated poloxamer 188 (GA–NH–POLO–NH–GA). The structure of the synthesized compound was confirmed by 1H-NMR and Fourier transform infrared (FT-IR) spectroscopy. Then the nanoparticles composed of GA–NH–POLO–NH–GA/chitosan (GA–NH–POLO–NH–GA/CTS) were prepared by an ionic gelation process. The characterization of the nanoparticles was measured by dynamic light scattering (DLS) and scanning electron microscope (SEM). The results showed that the nanoparticles were well dispersed with a spherical shape and the particle size was distributed between 100 nm and 300 nm. The cytotoxicity based on MTT assay against cells (QGY-7703 cells and L929 cells) showed that the nanoparticles had low toxicity and good biocompatibility. The encapsulation efficiency and drug loading of 5-fluorouracil-loaded nanoparticles (5-FU nanoparticles) were measured by high-performance liquid chromatography (HPLC) and fluorescence spectroscopy, ultraviolet-visible (UV-vis) absorbance. The encapsulation of 5-Fu-loaded CTS nanoparticles was 12.8% and the drug loading was 2.9%, while the encapsulation of 5-Fu-loaded GA–NH–POLO–NH–GA/CTS nanoparticles was 20.9% and the drug loading was 3.36%. The release profile showed that the GA–NH–POLO–NH–GA/CTS nanoparticles were available for sustained release of 5-Fu. The GA–NH–POLO–NH–GA/CTS nanoparticles have a higher affinity to the QGY-7703 cells, so indicated that the GA–NH–POLO–NH–GA/CTS nanoparticles have the capacity of liver-targeting in vitro.


Author(s):  
Rini Hamsidi ◽  
Wahyuni Wahyuni ◽  
Adryan Fristiohady ◽  
Muhammad Hajrul Malaka ◽  
Idin Sahidin ◽  
...  

Carthamus tinctorius Linn, also known as safflower, is a plant with the potential of being used in the production of antimalarial drugs. The purpose of this study was to isolate and identify the steroid compounds in the safflower and determine its antimalarial activity in vitro. The isolation process was conducted through extraction and chromatography methods. Then, the characterization of the isolated compounds was conducted through spectroscopic techniques which include Fourier Transform Infrared Spectroscopy (FT-IR), NMR 1-D (1H and 13C-NMR), and NMR 2-D (HMQC, HMBC, and H-H COZY) as well as comparing data with the existing literatures. In addition, the tests conducted were with variations of isolate concentrations (10, 1, 0.1, 0.01, and 0.001 μg/mL) against 3D7 strain of Plasmodium falciparum. Based on the FT-IR spectroscopic data, the steroid compounds isolated from safflowers might be stigmasterols. In addition, the isolates had -OH functional group in the region of 3431 cm-1, C-O in the region of 1053 cm-1, and Csp3-H in regions of 2960, 2934, and 2865 cm-1. The NMR 1-D data showed presence of 29 carbon atoms, while the protons were 48 in number. Furthermore, the IC50 value of the compound was 34.03 μg/mL with a percentage inhibition of 43.92% against the growth of P. falciparum. Therefore, it was classified as inactive agent in inhibiting the growth of malaria parasites, however, it could be used as a marker compound in C. tinctorius Linn extract.


2019 ◽  
Vol 31 (10) ◽  
pp. 2191-2196 ◽  
Author(s):  
S. Rathinamanivannan ◽  
K. Megha ◽  
Raja Chinnamanayakar ◽  
Ashok Kumar ◽  
M.R. Ezhilarasi

The new series of 1-(4,5-dihydro-5-phenyl-3-diphenylpyrazol-1-yl)butan-1-one derivatives were synthesized by cyclization method using biphenyl chalcone with n-butyric acid and hydrazine hydrate. The synthesized 1-(4,5-dihydro-5-phenyl-3-diphenylpyrazol-1-yl)butan-1-one derivatives chemical structures were confirmed from spectral data such as FT-IR, 1H and 13C NMR. 2-Pyrazoline derivatives were docked with bacterial (1UAG) and breast cancer (1OQA) protein. Based on high binding affinity score, the best compound was subjected to in vitro anticancer activity by MTT assay. Also, antimicrobial activity were studied for synthesized 2-pyrazoline derivatives.


2012 ◽  
Vol 499 ◽  
pp. 99-103
Author(s):  
Jun Chang ◽  
Cheng Wu Li ◽  
Gang Li

A series of polyesters containing 5-fluorouracil in the main chain were prepared by reacting potassium salt of 5-fluorouracil with different molecular weight ω-chloroalkyl chloroacetyl esters.The copolymers were characterized by FT-IR, 1H-NMR, VPO and UV spectroscopy. The drug release profile in vitro of the copolymers were studied, the results showed prodrug could slow release 5-FU or 5-FU units in different solution, they may be likely to become potential antitumor prodrug.


2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Samson A. Adeyemi ◽  
Yahya E. Choonara ◽  
Pradeep Kumar ◽  
Lisa C. du Toit ◽  
Viness Pillay

The aim of this study is to effectively enhance antitumor activities of endostatin by preparing polymeric nanocarriers. NMR and FT-IR spectra confirmed the successful grafting of the CHT-g-PEI and CHT-g-PEI-PEG-NH2 conjugates. SEM micrographs confirmed the shape of endostatin-loaded nanoparticles to be spherical while both TEM and zeta size results showed nanoparticle’s average size to be 100.6 nm having a positively charged surface with zeta potential of 7.95 mV. The concentrations of CHT and TPP as well as the changing pH conditions account for the increased swelling pattern of endostatin-loaded nanoparticles and influenced endostatin release in vitro. PEI increased the overall amine protonation while PEG aggravated endostatin encapsulation and release. Nanoparticles swell and release endostatin at acidic tumor pH of 6.8 compared to physiological pH of 7.4. The native CHT-g-PEI-PEG-NH2 conjugate showed high cytocompatibility above 80% cell viability across tested formulations. Endostatin-loaded nanoparticles showed a significant reduction in cell viability across tested formulations, with 5.32% cell death at 125 μg/mL and 13.36% at 250 μg/mL following 24 hours’ incubation period. Interestingly, more than a fourfold (61.68%) increment in cytotoxicity was observed at nanoparticle concentration of 1000 μg/mL. It was concluded that CHT-g-PEI-PEG-NH2 is an effective cargo for endostatin delivery with antiangiogenic effect in squamous cell carcinoma.


2012 ◽  
Vol 9 (2) ◽  
pp. 962-969 ◽  
Author(s):  
Zahraa Salim M. Al-Garawi ◽  
Ivan Hameed R. Tomi ◽  
Ali Hussein R. Al-Daraji

In this study, two new Schiff base compounds derived from the condensation reaction ofL-glycine andL-tryptophan with 4-methylbenzal-dehyde have been synthesized. The Schiff base compounds were characterized by FT-IR, UV and1H NMR spectroscopy. Their effects on the activity of total (ACP), prostatic (PAP) and non prostatic (NPA) acid phosphatase enzymes were studied. The Schiff base derived fromL-glycine (A) demonstrated inhibition effect on the ACP and NPA activities and activation effect on PAP activity. The Schiff base derived fromL-tryptophan (B) demonstrated semi fixed inhibition effects on the ACP and NPA activities at high concentrations (5.5×10-2, 5.5×10-3and 5.5×10-4M) and activator effect at low concentration (5.5×10-5M) while it was exhibits as activator on PAP activity.


2021 ◽  
Vol 11 (1) ◽  
pp. 3249-3260

Herein, we describe the synthesis and characterization of a Schiff base ligand (E)-N'-(2-hydroxybenzylidene)-4-methoxybenzohydrazide (HBMB) and its Mn(II), Ni(II), and Cu(II) metal complexes (C1-C3) respectively. The ligand HBMB was synthesized by reacting condensation of salicylaldehyde and 4-methoxy benzohydrazide in a 1:1 molar ratio. The structure of HBMB and its metal complexes (C1-C3) were evaluated by using UV-Vis, FT-IR, 1H-NMR, mass spectroscopy as well as on the basis of elemental analysis, conductivity measurements, and thermogravimetric techniques (TGA). The synthesized molecules' tumoricidal properties were performed against human breast cancer (MCF-7) and colon cancer (HT 29) cell lines. The biological results indicated that the ligand, HBMB, and metal complexes possess dose-dependent selective cytotoxicity against the tested carcinoma cells. The synthesized compounds were further evaluated for their in vitro antimicrobial activities against Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli), and fungal strains (Aspergillus niger).


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