RESUMO
Photodynamic therapy has emerged as an alternative treatment for cutaneous leishmaniasis, and compounds with photocatalytic behavior are promising candidates to develop new therapeutic strategies for the treatment of this parasitic disease. Titanium dioxide TiO2 is a semiconductor ceramic material that shows excellent photocatalytic and antimicrobial activity under Ultraviolet irradiation. Due to the harmful effects of UV radiation, many efforts have been made in order to enhance both photocatalytic and antimicrobial properties of TiO2 in the visible region of the spectrum by doping or through modifications in the route of synthesis. Herein, Fe-, Zn-, or Pt- doped TiO2 nanostructures were synthesized by solution-combustion route. The obtained compounds presented aggregates of 100â¯nm, formed by particles smaller than 20â¯nm. Doping compounds shift the absorption spectrum towards the visible region, allowing production of reactive oxygen species in the presence of oxygen and molecular water when the system is irradiated in the visible spectrum. The Pt (EC50â¯=â¯18.2⯱â¯0.8⯵g/mL) and Zn (EC50â¯=â¯16.4⯱â¯0.3⯵g/mL) -doped TiO2 presented the higher antileishmanial activities under visible irradiation and their application as photosensitizers in photodynamic therapy (PDT) strategies for the treatment of cutaneous leishmaniasis should be considered.
Assuntos
Leishmania/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Fármacos Fotossensibilizantes/farmacologia , Titânio/química , Raios Ultravioleta , Animais , Antracenos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Ferro/química , Leishmania/metabolismo , Leishmania/efeitos da radiação , Leishmaniose/tratamento farmacológico , Leishmaniose/parasitologia , Macrófagos Peritoneais/citologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Macrófagos Peritoneais/efeitos da radiação , Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico , Camundongos , Microscopia Eletrônica de Transmissão , Perileno/análogos & derivados , Perileno/química , Perileno/farmacologia , Perileno/uso terapêutico , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Espectrometria de Fluorescência , Difração de Raios X , Zinco/químicaRESUMO
Monitoring bacteria growth and motion in environments is fundamental to understand, for instance, how they proliferate and contaminate organism. Therefore, techniques to fabricate microenvironments for in situ and in vivo studies are interesting for that purpose. In this work we used two-photon polymerization to fabricate microenvironments and, as a proof of principle, we demonstrated the development of the bacteria ATCC 25922 Escherichia coli (E. coli) into the microstructure surroundings. Two varieties of polymeric microenvironments are presented: (i) a microenvironment doped at specific site with ciprofloxacin, an antibiotic typically used in the treatment of diseases caused by E. coli and (ii) micro-fences, which serve as traps for bacteria. These microenvironments, fabricated by two-photon polymerization, may be a potential platform for drug delivery system, by promoting or inhibiting the growth of bacteria in specific biological or synthetic sites.