Jan Długosz University

About: Jan Długosz University is a education organization based out in Częstochowa, Poland. It is known for research contribution in the topics: Crystal structure & Luminescence. The organization has 749 authors who have published 2311 publications receiving 19395 citations. The organization is also known as: Higher Teacher Education School.

Structure, rheological, textural and thermal properties of potato starch – Inulin gels

Abstract: This paper presents studies on the structure, rheological, textural and thermal properties of potato starch + inulin gels at widely differentiated overall concentration and proportions of both gel components. The increase of polysaccharides concentration changed viscoelastic properties and firmness of gels, compared to control samples. Noticeable differences were observed at 6% concentration of starch and 25% of inulin. DSC suggested that gelatinization of potato starch with inulin produced the binary gel of the common network, that could resulted from the competition of both components for water (caused by high affinity of these polysaccharides to water molecules), which was a key factor influencing starch gelatinization and affected properties of the obtained gels.

Antitumor properties and toxicity of dextran-methotrexate conjugates are dependent on the molecular weight of the carrier.

Abstract: Methotrexate (MTX) is widely utilized in the clinical treatment of many forms of cancer. However, the drug has a short plasma half-life and causes toxic effects on normal proliferating cells. Conjugation with carriers is a possible way to alter these disadvantageous pharmacokinetics. Our aim was to synthesize dextran-MTX (D-MTX) conjugates, using carriers with molecular weights (Mw) ranging from 10 kDa to 500 kDa. Their in vitro and in vivo properties were compared with free MTX. The in vitro studies revealed that D-MTX conjugates had 4- to 10-fold lower antiproliferative effects against neoplastic cell lines compared to free MTX. There was a negative relationship between the Mw of the carrier and the antiproliferative effect of the respective conjugate. The data obtained in a mouse leukemia P388 in vivo model suggested that a lower in vitro antiproliferative effect of the conjugates does not result in diminished antileukemic activity in vivo. The toxicity of the conjugates was greater in comparison with the parent drug and tended to rise with increasing Mw. However, no superiority over free MTX in terms of an antileukemic effect was demonstrated. In particular, the D-MTX conjugate based on the dextran with Mw 10 kDa showed a comparable antileukemic effect with an even lower toxicity than that of free MTX. The data suggest that at least the toxicity of conjugates is dependent on the Mw of the carrier. This fact should be taken into account when designing new anticancer polymer-drug compounds.

Extended positron‐trapping defects in insulating MgAl2O4 spinel‐type ceramics

Abstract: Extended defects in insulating nanoporous MgAl2O4 spinel-type ceramics which trap positrons are characterized by positron annihilation lifetime spectroscopy before and after water-immersion treatment. It is shown that in both cases the same type of positron traps prevails, but positron trapping in defects near grain boundaries occurs more efficiently in water-moistened ceramics. It is shown the more perfect structure of ceramics, the more considerable changes occur in the positron trapping parameters of water-moistened ceramics. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)