New Biocompatible Polyurethanes: Synthesis, Structural Characterization and Cytotoxicity

The synthesis of four samples of new polyurethanes was evaluated by changing the ratio of the diol monomers used, poly(propylene glycol) (PPG) and D-isosorbide, in the presence of aliphatic isocyanates such as the isophorone diisocyanate (IPDI) and 4,4′-methylenebis(cyclohexyl isocyanate) (HMDI). The thermal properties of the four polymers obtained were determined by DSC, exhibiting Tg values in the range 55-70 ºC, and their molecular structure characterized by FTIR, 1H and 13C NMR spectroscopies. The diffusion coefficients of these polymers in solution were measured by the Pulse Gradient Spin Echo (PGSE) NMR method, enabling the calculation of the corresponding hydrodynamic radii in diluted solution (1.62–2.65 nm). The molecular weights were determined by GPC/SEC and compared with the values determined by quantitative 13C NMR analysis. Finally, the biocompatibility of the polyurethanes was assessed using the HaCaT keratinocyte cell line by the MTT reduction assay method showing values superior to 70% cell viability.

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Synthesis and Characterization of Isosorbide-Based Polyurethanes Exhibiting Low Cytotoxicity Towards HaCaT Human Skin Cells

Polymers ◽

10.3390/polym10101170 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1170 ◽

Cited By ~ 2

Author(s):

Barbara Gregorí Valdés ◽

Clara Gomes ◽

Pedro Gomes ◽

José Ascenso ◽

Hermínio Diogo ◽

...

Keyword(s):

13C Nmr ◽

Spin Echo ◽

Assay Method ◽

Molecular Weights ◽

Pulse Gradient ◽

Diluted Solution ◽

Keratinocyte Cell ◽

Low Cytotoxicity ◽

Hacat Keratinocyte ◽

Pgse Nmr

The synthesis of four samples of new polyurethanes was evaluated by changing the ratio of the diol monomers used, poly(propylene glycol) (PPG) and D-isosorbide, in the presence of aliphatic isocyanates such as the isophorone diisocyanate (IPDI) and 4,4′-methylenebis(cyclohexyl isocyanate) (HMDI). The thermal properties of the four polymers obtained were determined by DSC, exhibiting Tg values in the range 55–70 °C, and their molecular structure characterized by FTIR, 1H, and 13C NMR spectroscopies. The diffusion coefficients of these polymers in solution were measured by the Pulse Gradient Spin Echo (PGSE) NMR method, enabling the calculation of the corresponding hydrodynamic radii in diluted solution (1.62–2.65 nm). The molecular weights were determined by GPC/SEC and compared with the values determined by a quantitative 13C NMR analysis. Finally, the biocompatibility of the polyurethanes was assessed using the HaCaT keratinocyte cell line by the MTT reduction assay method showing values superior to 70% cell viability.

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Synthesis and Characterization of Some New Esters Containing Heterocyclic and Derived From Azo Dyes

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.9.2.29 ◽

2019 ◽

Vol 9 (02) ◽

Author(s):

Zena G. Alrecabi ◽

Zainab Amer ◽

Naeemah Al-Lami

Keyword(s):

Schiff Base ◽

13C Nmr ◽

Azo Dyes ◽

Spectral Methods ◽

Anthranilic Acid ◽

Heterocyclic Compounds ◽

Synthesis And Characterization ◽

Cooh Group ◽

Molecular Weights

This study including prepared new colored esters containing heterocyclic with high molecular weights. In the first part of work we synthesized azo dyes [1,2] from the reaction p-toluidine with β-naphthol and o-nitro phenol, thin we synthesized Schiff bases [3,4] by the reaction anthranilic acid with benzaldehyde and dimethyl benzaldehyde. The reaction azo dyes (contain OH group) with Schiff base (contain COOH group) these led to produce the new colored esters [A1-A4]. The second part of work was modification the (C=N-) group in esters to heterocyclic compounds by reacting with phenyl iso cyanide to produce new β-lactam [B1-B4] and with anthranilic acid to get new hydroquinazoline [C1-C4]. All these compounds were characterized by physical properties and spectral methods FTIR, 1H-NMR and 13C-NMR.

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A New Technique for the Enumeration of Rotaviruses in Wastewater Samples

Water Science & Technology ◽

10.2166/wst.1989.0085 ◽

1989 ◽

Vol 21 (3) ◽

pp. 99-104 ◽

Cited By ~ 2

Author(s):

J. I. Oragui ◽

D. D. Mara ◽

S. A. Silva ◽

A. M. Konig

Keyword(s):

Inorganic Ions ◽

Assay Method ◽

Toxic Substances ◽

Waste Stabilization Ponds ◽

Virus Removal ◽

Molecular Weights ◽

Large Numbers ◽

Waste Stabilization ◽

A New Technique ◽

Wastewater Samples

Rotaviruses are generally excreted in large numbers in diarrhoeal stools, but in wastewaters their numbers are subject to variations. Detection and enumeration of these viruses involve a concentration step followed by an assay method. Enumeration in wastewater concentrates is complicated by the presence of toxic substances which are often concentrated with the viruses. These toxic substances often cause the destruction of cells during rotavirus assay, thus leading to underestimation of viral numbers. Such concentrates were detoxified by a simple and effective method using polyacrylamide (Biogel P-6DG) or dextran (Sephadex G50) beads. Concentrates (10 ml) were mixed with 0.5 g gel and the mixtures were allowed to stand for 2 h at room temperature during which time the beads swell by the passage of water into them along with inorganic ions and substances with molecular weights of less than 30,000. The supernatants were then decontaminated with antibiotics and assayed for rotaviruses by the indirect immunofluorescent technique. Most untreated ultrafiltrates of raw sewage and those from anaerobic ponds were found to be too toxic to MA104 and LLC MK2 cells, whereas the above treatment rendered over 90% of wastewater concentrates non-toxic to cells. This technique was used to study virus removal in samples from deep waste stabilization ponds in northeast Brazil.

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