Fizikalni mehanizmi i metode u tumorskim terapijama i prijenosu lijekova do tumora

In addition to several well-known drug delivery strategies developed to facilitate effective chemotherapy with anticancer agents, some new approaches have been recently established, based on specific effects arising from the applications of ultrasound, magnetic and electric fields on drug delivery systems. This paper gives an overview of newly developed methods of drug delivery to tumors and of the related anticancer therapies based on the combined use of different physical methods and specific drug carriers. The conventional strategies and new approaches have been put into perspective to revisit the existing and to propose new directions to overcome the threatening problem of cancer diseases.Osim dobro poznatih metoda prijenosa lijekova u kemoterapijskom pristupu liječenja tumora, nedavno su otkriveni novi načini prijenosa koji se zasnivaju na specifičnim mehanizmima uzrokovanim upotrebom ultrazvuka, magnetskih i električnih polja. Članak sadrži prikaz fizikalnih mehanizama na kojima se temelje ove nove metode, kao i pregled novootkrivenih prijenosnika lijekova (Pluronske micele, magnetoliposomi, magnetski fluidi), novih terapija tumora (magnetska hipertermija, elektrokemoterapija) i najnovijih istraživanja temeljenih na fizikalnom pristupu ovoj problematici

Clay (Montmorillonite K10) catalysis of the Michael addition of alpha,beta-unsaturated carbonyl compounds to indoles: The beneficial role of alcohols

The Michael addition of methylvinylketone to indole can be performed under smooth conditions by running the reaction in the presence of an acidic clay catalyst (K10 Montmorillonite) and an aliphatic alcohol such as ethanol or 2-propanol. Presence of an alcohol along with a polar solvent (nitromethane) in the reaction medium considerably improves the reaction

Subcellular distribution of glycolyltransferases in rodent liver and their significance in special reference to the synthesis of N-glycolyneuraminic acid.

The enzymic synthesis, transfer, and utilization of glycolyl-CoA (i.e. 2-hydroxyacetyl-CoA) have been studied in rat and mouse livers. On the one hand, these tissues contain the enzyme activities allowing the synthesis of glycolyl-CoA from fatty acids (palmitate omega-hydroxylase, omega-hydroxypalmitoyl-CoA synthetase, and mitochondrial beta-oxidation of omega-hydroxypalmitoyl-CoA) and 3-hydroxypyruvic acid (oxidation by intact mitochondria). On the other hand, three types of glycolyltransferase activities can be demonstrated in rodent livers, depending on either carnitine, glucosamine, or glucosamine-6-phosphate. The subcellular distributions of these glycolyltransferase activities are similar to those of the corresponding acetyltransferase counterparts. Concerning carnitine glycolytransferase, the activity is widely distributed in the subcellular fractions, pointing out its occurrence in most cell compartments. By contrast, the glucosamine and glucosamine-6-phosphate glycolytransferase activities were located preferentially in the microsomal fraction. The condensation between glycolyl-CoA and glucosamine (or glucosamine-6-phosphate) raises the interesting question of the nature and the role of the resulting glycolylglucosamine molecule, especially in an alternative N-glycolylneuraminic acid synthesis pathway

Molecular Modeling Studies On 11-beta-aminoethoxyphenyl and 7-alpha-aminoethoxyphenyl Estradiols - Evidence Suggesting a Common Hydrophobic Pocket in Estrogen-receptor

Molecular modeling studies were performed on 11 beta and 7 alpha-aminoethoxyphenyl estradiols to determine whether these compounds may interact with the same receptor subsite. Energy minimization and molecular dynamics studies lend support to this hypothesis

Comparative study of acid and basic catalysis in microwave assistance of Willgerodt-Kindler reaction for thiobenzamides and derivatives synthesis

Montmorillonite K-10 was used in the acid catalysis of the Willgerodt-Kindler’s reaction (WK) under microwave heating for synthesis of thiobenzamides. Yields of 67% and 43% for the synthesis of morpholin- 4- yl (phenyl) methanethione (1) and [4 - (dimethylamino) phenyl] (morpholin-4-yl) methanethione (2) respectively, showed that the mixture (aldehyde, sulfur, morpholine and K-10) is quite suitable for this reaction. This enables to deduct that the conditions of acid catalysis with the K-10 are favourable to the WK’s reaction of carbonyl compounds. Furthermore, yields of 81% and 74% respectively for the synthesis of thioamides 1 and 2 in basic catalysis with 4-methylmorpholine allows to confirm that this reaction is more advantageous in basic catalysis. The structures of thioamides synthesized were characterized and confirmed by spectroscopy Infrared (IR), nuclear magnetic resonance (1H and 13C NMR) and mass spectrometry (MS).Keywords: Montmorillonite K-10, 4-methylmorpholine, morpholin-4-yl(phenyl)methanethione, [4- (dimethylamino)phenyl](morpholin-4-yl)methanethion

Poly(diethyl methylidenemalonate) nanoparticles as a potential drug carrier: preparation, distribution and elimination after intravenous and peroral administration to mice.

Polymerization of diethyl methylidenemalonate (DEMM, 1a) in 0.1 M phosphate buffer containing 1% dextran 70 yields nanoparticles of a diameter ranging from 140 to 250 nm depending on the pH value (6.7 to 8.7). The weight-average and number-average molecular weight of the resulting polymer were 3791 and 1084, respectively. Approximately 95% of the 14C-labeled poly(DEMM) nanoparticles were found in liver and spleen 1 h after iv administration. A statistically significant (p less than 0.01) approximately 10% decrease of the radioactivity was observed in the liver over a 3-month period. The poly(DEMM) nanoparticles were not absorbed and were totally cleared from the gastrointestinal tract 24 h after oral dosage. The very slow bioelimination process observed after iv administration limits the usefulness of poly(DEMM) nanoparticles as a systemic drug carrier. Nevertheless, their oral administration as bioavailability enhancers can be envisaged. Moreover, the fact that nanoparticles are readily produced in a medium near neutrality should be emphasized