RESUMO
Cerium dioxide nanoparticles (CeO2 NPs) with a high value of ζ-potential (≥30 mV) have been synthesized in reverse microemulsions and they are able to form the high-stable aqueous suspension without any additional stabilizers. It has been shown that the interaction of such CeO2 NPs with transport proteins, such as BSA, affects their molecular conformation and biochemical activity. The observed changes in the UV-absorbance spectrum and intrinsic fluorescence quenching of BSA molecule are indicative of the occurrence of structural changes caused by binding with the surface of CeO2 NPs. Low affinity between BSA and CeO2 NPs has been confirmed by differential scanning calorimetry (DSC). Moreover, CeO2 NPs can act as regenerative free-radical scavengers, and their antioxidant activity depends on the concentration. The positive charge of CeO2 NPs can be attributed to their low toxicity toward human malignant lymphocytes MT-4 and breast cancer cells MCF-7 however, the morphofunctional features of MCF-7 cells interacting with CeO2 NPs are indicative of the decrease in oncogenicity.
Assuntos
Cério/farmacologia , Sequestradores de Radicais Livres/farmacologia , Nanopartículas , Animais , Bovinos , Cério/química , Sequestradores de Radicais Livres/química , Humanos , Células MCF-7 , Nanopartículas/química , Soroalbumina Bovina/metabolismoRESUMO
The synthesis of multifunctional spirocycles was achieved from common cyclic carboxylic acids (cyclobutane carboxylate, cyclopentane carboxylate, l-proline, etc.). The whole sequence included only two chemical steps-synthesis of azetidinones, and reduction into azetidines. The obtained spirocyclic amino acids were incorporated into a structure of the known anesthetic drug Bupivacaine. The obtained analogues were more active and less toxic than the original drug. We believe that this discovery will lead to a wide use of spirocyclic building blocks in drug discovery in the near future.
Assuntos
Azetidinas/síntese química , Azetidinas/farmacologia , Descoberta de Drogas , Compostos de Espiro/síntese química , Compostos de Espiro/farmacologia , Anestésicos/química , Azetidinas/química , Bupivacaína/química , Ácidos Carboxílicos/química , Ciclopentanos/química , Prolina/química , Compostos de Espiro/químicaRESUMO
Among many and various products, born by the modern nanotechnology, gold nanoparticles roused a special interest of biomedical researchers. Unique features of the nanoparticles allow to use them not only as effective transporters for therapeutic agents but also as basic components of nanocomposite preparations intended for targeted photodynamic and photothermal therapy of tumours. In the review, physical, chemical and biological properties of gold nanoparticles which can promote PDT efficiency of a designed nanocomposite, are briefly characterized, and promising trends in creation of gold-containing composite photosensitizers are analysed.