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The aim of this work is research dedicated to the search for new bactericidal systems for use in cosmetic formulations, dermocosmetics, or the production of wound dressings. Over the last two decades, chitosan, due to its special biological activity, has become a highly indispensable biopolymer with very wide application possibilities. Reports in the literature on the antibacterial effects of chitosan are very diverse, but our research has shown that they can be successfully improved through chemical modification. Therefore, in this study, results on the synthesis of new chitosan-based Schiff bases, dCsSB-SFD and dCsSB-PCA, are obtained using two aldehydes: sodium 4-formylbenzene-1,3-disulfonate (SFD) and 2-pyridine carboxaldehyde (PCA), respectively. Chitosan derivatives synthesized in this way demonstrate stronger antimicrobial activity. Carrying out the procedure of grafting chitosan with a caproyl chain allowed obtaining compatible blends of chitosan derivatives with κ-carrageenan, which are stable hydrogels with a high swelling coefficient. Furthermore, the covalently bounded poly(ε-caprolactone) (PCL) chain improved the solubility of obtained polymers in organic solvents. In this respect, the Schiff base-containing polymers obtained in this study, with special hydrogel and antimicrobial properties, are very promising materials for potential use as a controlled-release formulation of both hydrophilic and hydrophobic drugs in cosmetic products for skin health. [ABSTRACT FROM AUTHOR]

The interest in combining chemosensitizers with cytostatics in cancer therapy is growing, which causes also a need to develop their delivery systems. Example of the combination with beneficial therapeutic effects is docetaxel (Dtx) and resveratrol (Res). Although poly(lactide)‐co‐poly(ethylene glycol) (PLA–PEG) micelles have been considered as one of the most promising platforms for drug delivery, their properties may depend on the stereoisomeric form of hydrophobic block. Therefore, the aim of this study was evaluation of the effect of PLA block on co‐encapsulation and release rate of Dtx and Res, which has not been studied so far. This article presents a comparison of single‐ (Dtx or Res) and dual‐drug (Dtx and Res) loaded micelles obtained from poly(l,l‐lactide)‐co‐poly(ethylene glycol) (PLLA‐PEG) and poly(d,l‐lactide)‐co‐poly(ethylene glycol) (PDLLA‐PEG). The analyzes of the micelles have been conducted including morphology, drug(s) encapsulation efficiency, intermolecular interactions, in vitro drug release, and cytotoxicity. Differences in drug loading ability and release profile have been observed between Res and Dtx but also depending on the polymer and number of drugs in micelles (single vs. dual loaded). The PLLA‐PEG micelles have a significantly higher Dtx encapsulation capacity than PDLLA‐PEG micelles. The highest cytotoxicity was shown for Dtx and Res dual‐loaded micelles, regardless of the polymer. The findings may be used for selection of PLA‐based drug delivery systems containing Dtx and Res. [ABSTRACT FROM AUTHOR]

The aim of this study was to estimate the structure of new polyurethanes with the potential to be used in medicine. Atactic poly[( R,S)-3-hydroxybutyrate], obtained via a ring-opening polymerization, and polycaprolactonediol or polyoxytetramethylenediol were used to built the soft segments. 4,4′-methylene dicyclohexyl diisocyanate and 1,4-butanediol were the components to form hard segments. At FTIR spectra of obtained polyurethanes the bands attributed to NCO groups completely disappeared, similarly as these of OH groups and the new band characteristic for stretching vibrations of bonded urethane NH groups appeared. Polyurethanes with low-molecular weight were obtained. The observation of FTIR and 1H-NMR spectra had been suggested that NH groups form two types of hydrogen bonds: with CO urethane (possibly with ester group) and ether groups. An addition of poly[( R,S)-3-hydroxybutyrate] caused the slight increase in number of urethane-urethane hydrogen bonds. For some of polyurethanes (based on polyoxytetramethylenediol) the allophanate structures were obtained. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

Abstract: Results of X-ray diffraction, infrared spectroscopy, differential scanning calorimetry and optical emission together with lifetime measurements of phosphate fluoroindate glasses activated by Pr3+ ions are reported. Structural, thermal and optical behavior of multicomponent oxyfluoride glasses has been analyzed as a function of P2O5 concentration. Short glass-forming region exists for InF3-based system with P2O5 additives. For low (4–12%) P2O5 concentration, thermally stable and transparent non-crystalline oxyfluoride samples based on InF3 with relatively high ΔT factors were prepared, which can be promising for fiber drawing. For higher (16%) P2O5 concentrations, several diffraction lines due to the InOF polycrystalline phase were identified. Absorption edge and luminescence bands for Pr3+ ions in fluoroindate glasses are shifted in the direction of the lower frequency region with increasing of P2O5 content. Luminescence from both 3P0 and 1D2 excited states of Pr3+ ions was registered. The 1D2 luminescence lifetime close to about 35μs is independent on P2O5 concentration. [Copyright &y& Elsevier]

The paper presents a synthesis of poly(l-lactide) with bacteriostatic properties. This polymer was obtained by ring-opening polymerization of the lactide initiated by selected low-toxic zinc complexes, Zn[(acac)(L)H2O], where L represents N-(pyridin-4-ylmethylene) tryptophan or N-(2-pyridin-4-ylethylidene) phenylalanine. These complexes were obtained by reaction of Zn[(acac)2 H2O] and Schiff bases, the products of the condensation of amino acids and 4-pyridinecarboxaldehyde. The composition, structure, and geometry of the synthesized complexes were determined by NMR and FTIR spectroscopy, elemental analysis, and molecular modeling. Both complexes showed the geometry of a distorted trigonal bipyramid. The antibacterial and antifungal activities of both complexes were found to be much stronger than those of the primary Schiff bases. The present study showed a higher efficiency of polymerization when initiated by the obtained zinc complexes than when initiated by the zinc(II) acetylacetonate complex. The synthesized polylactide showed antibacterial properties, especially the product obtained by polymerization initiated by a zinc(II) complex with a ligand based on l-phenylalanine. The polylactide showed a particularly strong antimicrobial effect against Pseudomonas aeruginosa, Staphylococcus aureus, and Aspergillus brasiliensis. At the same time, this polymer does not exhibit fibroblast cytotoxicity. [ABSTRACT FROM AUTHOR]