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The discovery of novel biodegradable biomaterials able to support and control cellular activity as well as development of an enhanced and efficient method for their fabrication, are of paramount importance in the field of tissue engineering. This study highlights the design of novel degradable hydrogels based on gelatin and hydroxyethyl (meth)acrylates using the innovative combined two-step sequential microwave-assisted and UV photo-polymerization technique. Chemical composition, morphology, swelling capacity and degradation rate of the synthesized hydrogels were evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), swelling and weight loss measurements. As an initial step for evaluation of performance of the hydrogels in the biological environment, the in vitro biocompatibility of these hydrogels, was evaluated using L929 mouse fibroblasts. Obtained results demonstrated that the hydrogels possess a porous morphology with interconnected pores, 50% in vitro degradation after 7 months, and satisfied biocompatibility on L929 fibroblast cells. These unique performances of the hydrogels make them promising candidates for in vivo evaluation in clinical studies aiming at tissue regeneration.

Design of a new drug entity is usually preceded by analysis of quantitative structure activity (properties) relationships, QSA(P)R. Six newly synthesized succinimide derivatives have been determined for (i) in silico physico-chemical descriptors, pharmacokinetic and toxicity predictors, (ii) in vitro biological activity on four different carcinoma cell lines and on normal fetal lung cells and (iii) lipophilicity on liquid chromatography. All compounds observed were predicted for good permeability and solubility, good oral absorption rate and moderate volume of distribution as well as for modest blood brain permeation, followed by acceptable observed toxicity. In silico determined lipophilicity, permeability through jejunum and aqueous solubility were correlated with experimentally obtained lipophilic constants (by use of high pressure liquid chromatography) and linear correlations were obtained. Absorption rate and volume of distribution were predicted by chromatographic lipophilicity measurements while permeation through blood bran barrier was predicted dominantly by molecular size defined with molecular weight. Five compounds have demonstrated antiproliferative activity toward cervix carcinoma HeLa cell lines; three were cytotoxic against breast carcinoma MCF-7 cells, while one inhibited proliferation of colon carcinoma HT 29 cell lines. Only one compound was cytotoxic toward normal cell lines, while other compounds were proven as safe. Antiproliferative potential against HeLa cells was described as exponential function of lipophilicity. Based on obtained results, lead compounds were selected.

Numerous structurally different amides and imides including succinimide derivatives exhibit diverse bioactive potential. The development of new compounds requires rationalization in the design in or- der to provide structural changes that guarantee favorable physico-chemical properties, pharmacological activity and safety. In the present research, a comprehensive study with comparison of the chromato- graphic lipophilicity and other physico-chemical properties of five groups of 1-arylsuccinimide derivatives was conducted. The chemometric analysis of their physico-chemical properties was carried out by us- ing unsupervised (hierarchical cluster analysis and principal component analysis) and supervised pattern recognition methods (linear discriminant analysis), while the correlations between the in silico molecular features and chromatographic lipophilicity were examined applying linear and non-linear Quantitative Structure–Retention Relationship (QSRR) approaches. The main aim of the conducted research was to determine similarities and dissimilarities among the studied 1-arylsuccinimides, to point out the molec- ular features which have significant influence on their lipophilicity, as well as to establish high-quality QSRR models which can be used in prediction of chromatographic lipophilicity of structurally similar 1-arylsuccinimides. This study is a continuation of analysis and determination of the physico-chemical properties of 1-arylsuccinimides which could be important guidelines in further in vitro and eventually in vivo studies of their biological potential.

Spectral properties, solvatochromism and azo-hydrazone tautomerism of ten 5-(substituted phenylazo)-3-cyano-6-hydroxy-1-(2-hydroxyethyl)-4-methyl-2-pyridones in twenty-two solvents are investigated. For quantitative evaluation of the solvent effects on the UV–vis absorption maxima, the principles of the linear solvation energy relationships are used, i.e. models proposed by Kamlet–Taft and Catalan. Linear free energy relationships are applied to the UV–vis absorption spectra and correlation of absorption frequencies with Hammett substituent constants are performed. Furthermore, the influence of the electronic nature of the substituents on 1H and 13C NMR shifts is investigated by simple and extended Hammett equations, as well as by Swain–Lupton equation.

The absorption spectra of twelve 5-arylidene-2,4-thiazolidinediones were recorded in twenty one solvents in the range from 300 to 600 nm. The effect of specific and non-specific solvent-solute interactions on the absorption maxima shifts were evaluated by using the Catalan solvent parameter set. Furthermore, the experimental findings were interpreted with the aid of ab initio MP2 and time-dependent density functional (TD-DFT) methods. It was found that different substituents significantly change the extent of conjugation in the molecules and further affect their intramolecular charge transfer character. (C) 2011 Elsevier B.V. All rights reserved.

Absorption spectra of seventeen 5-(3- and 4-substituted arylazo)-4,6-dimethyl-3-cyano-2-pyridones have been recorded in 12 protic and aprotic solvents in the range 200–600 nm. The effects of substituents on the absorption spectra of these new azo dyes are interpreted by correlation of absorption frequencies with Hammett equation. The solute–solvent interactions were clarified on the basis of linear solvation energy relationships concept proposed by Kamlet and Taft. The 2-pyridone/2-hydroxypiridine tautomeric equilibration is found to depend upon substituents as well as on solvents.

Absorption spectra of ten 5-(4-substituted arylazo)-6-hydroxy-4-methyl-3-cyano-2-pyridones have been recorded in fifteen solvents in the range 200–600 nm. The substituents at the phenyl nucleus are as follows: OH, OCH 3 , CH 3 , C 2 H 5 , H, Cl, Br, I, COOH and NO 2 . The effects of substituents on the absorption spectra of investigated compounds are interpreted by correlation of absorption frequencies with simple Hammett equation. The effects of solvent polarity and solvent/solute hydrogen bonding interactions are analyzed by means of linear solvation energy relationships concept proposed by Kamlet and Taft. The azo-hydrazone tuatomeric equilibration is found to depend upon substituents as well as on solvents.

The infrared spectra in the region of fundamental CO stretching vibrations in methylenchloride were measured for nine 1,3-bis-substituted-5,5-dimethylhydantoins. The arithmetic means of wave numbers of symmetric and antysymmetric CO stretching vibrations are correlated with Taft's inductive σ* substituent constants. The mechanism of the transmission of substituent effects in hydantoin systems is discussed.

The ultraviolet absorption spectra of a number of cis and trans-3- and 4-substituted cinnamic acids have been determined. Examination of the obtained spectra shows that there is a fair linear relation between the positions of the absorption bands for the electronic transitions of the carbonyl group and the Hammett substituent constants. The plot of the λ max values of the cinnamic acids versus the rate constants for he corresponding acids with diazodiphenylmethane in ethanol gave a fair correlations. This relationship was discussed in view of the proportionality of the energy of activation for the reaction of these acids with DDM in ethanol and the energy for the electronic transitions in the carbonyl group under the influence of UV radiation.

The ultraviolet absorption spectra of 2-phenyl-δ,β-unsaturated carboxylic acids have been determined and λ max for the electronic transitions of the carbonyl group successfully correlated with Hammett substituent constants. The obtained λ max were also correlated with the rate constants for the reaction of the corresponding acids with DDM in ethanol. This relationship was discussed in view of the proportionality of the activation energies for the mentioned reaction and energy for electronic transition of the carbonyl group.