Spectroscopic and structural investigations of blue afwillite from Ma'ale Adummim locality, Palestinian Autonomy.

Until now, only the colourless crystals of mineral afwillite, Ca3(HSiO4)2·2H2O, were known from several localities around the world. Present work focuses on blue afwillite counterparts from the Ma'ale Adummim locality in Palestine. Using the wide spectrum of analytical methods we attempted to identify the causes of this unusual colour. Structural investigation confirms the presence of two tetrahedral SiO3OH units connected by hydrogen bonds. The Raman spectrum of afwillite, obtained for the first time, shows the increased number of bands in the range of 785-970 cm-1, whose assignation was correlated with the presence of two different kinds of structural units: (SiO3OH)3- and its deprotonated counterpart (SiO4)4-. The heating process at 250 °C, in addition to the colour changes from blue to pastel green, shows the intensity reduction and disappearing of some Raman bands attributed mainly to SiO3OH units. The IR investigation confirms also the presence of that unit and provides information that the position and designation of infrared bands above ∼2300 cm-1 is related to the strength of hydrogen bonds within the structure. The stretching and bending OH vibrations of afwillite sample show the partial shift to the lower spectral frequencies after the H/D isotopic exchange in OH or H2O groups. Based on the results of the electron absorption and luminescence analyses it has been proposed that the blue colour of afwillite is caused by hole oxygen defect, most probably SiO3-.

Experimental anticancer therapy with vascular-disruptive peptide and liposome-entrapped chemotherapeutic agent.

Vasculature is essential for the sustained growth of solid tumors and metastases. Tumor cells surviving vascular-disruptive therapeutic intervention (especially those present at the tumor rim) can contribute to tumor regrowth. The aim was to strengthen, by carrier-mediated delivery of a chemotherapeutic, the curative effects of a bifunctional anti-vascular oligopeptide capable of inducing vascular shutdown and tumor shrinkage. For the in vitro experiments and animal therapy, ACDCRGDCFC-GG-(D)(KLAKLAK)(2) peptide (900 microM in D-PBSA, i.e. Dulbecco's PBS without Ca(2+) and Mg(2+)) and size-calibrated, passively or actively targeted liposomes based on distearoylphosphatidylcholine, cholesterol, and N-carbamoyl-methoxypolyethyleneglycol coupled to distearoylphosphatidylethanolamine (PEG-DSPE) and containing gradient-entrapped doxorubicin were used. The KB (human nasopharyngeal carcinoma) cell line overexpressing folate receptors was used in the fluorescence studies of liposomal uptake. The B16-F10 melanoma cell line was used for confirming, by flow cytometry and confocal microscopy, doxorubicin intracellular transfer as well as to induce experimental tumors in C57BL/6 mice. Animal therapy was achieved with injections of vascular-disrupting peptide, doxorubicin-loaded liposomes, or alternating combined therapy. The results (tumor growth inhibition and survival) were compared using the Mann-Whitney U test and the log-rank test. Necrosis in H&E-stained tumor sections was assessed microscopically by pathologists. Treatment of C57BL/6 mice bearing B16-F10 experimental tumors with a combination of vascular-disruptive peptide and doxorubicin-carrying pegylated liposomes (either passively targeted liposomes (PTL) or folate receptor targeted) gave better therapeutic effects when tumor development was re-challenged with a second cycle of combined therapy. Marked inhibition of tumor growth and a statistically significant extension of the lifespan of the treated mice were observed when the re-challenge involved the use of folate receptor-targeted liposomes (FTL). Anticancer therapy involving vascular-disruptive peptide and doxorubicin delivered via pegylated folate receptor-targeted liposomes is more effective than either monotherapy, especially when tumor growth is re-challenged with the therapeutic combination.

Aromatic compounds in molecular phase of Baltic amber-synchronous luminescence analysis.

Synchronous luminescence analysis was performed in order to identify aromatic compounds in solvent extracts of Baltic amber. The investigated extracts were obtained, for comparisons, as products of extraction by various techniques and solvents. Methylene chloride and ethanol were applied independently for extraction at the ambient temperature (conservative extraction), as well as at the temperature of solvent boiling (extraction in Soxhlet apparatus). Ethanol, as the solvent, was also used for extraction in an ultrasonic bath and for the decoction process. The extraction, by techniques mentioned, of the analysed amber has resulted in products generally containing the same groups of aromatics: mainly naphthalenes, phenanthrenes and anthracenes. Among phenanthrenes, in all samples the retene was also identified, being one of the characteristic links of the diagenetic chain of chemical transformations of vegetal precursors. The identification of a series of individual compounds made, using the synchronous luminescence technique, was verified by the record of conventional emission and excitation spectra. Presented identified compounds were also confirmed by the results of GC-MS analysis. The luminescence analysis was also performed comparatively for fossil resin from Galicia, Spain (Cretaceous) older than Baltic amber (Tertiary, Eocene). The obtained preliminary results of synchronous luminescence analysis suggest the possibility of diversification in this manner of fossil resins of various ages by characterisation of aromatisation degree and alkyl substitution of aromatic rings. It is since well known that aromatisation progress is an indicator of a natural process of maturation of fossil organic matter. However, a greater number of samples should be taken to further testify to the investigations.