INVESTIGADORES
SANCHEZ Francisco Homero
artículos
Título:
Enhanced Singlet Oxygen Production by Photodynamic Therapy and a Novel Method for Its Intracellular Measurement
Autor/es:
SANDRA L. PENA LUENGAS; GUSTAVO HORACIO MARIN; KEVIN AVILES; F. H. SÁNCHEZ
Revista:
CANCER BIOTHERAPY AND RADIOPHARMACEUTICALS
Editorial:
MARY ANN LIEBERT INC
Referencias:
Año: 2014 vol. 29 p. 435 - 443
ISSN:
1084-9785
Resumen:
The generation of singlet oxygen (SO) in the presence of specific photosensitizers (PSs) or semiconductor
quantum dots (QDs) and its application in photodynamic therapy (PDT) is of great interest to develop cancer
therapies with no need of surgery, chemotherapy, and/or radiotherapy. This work was focused on the identification
of the main factors leading to the enhancement of SO production using Rose Bengal (RB), and
Methylene Blue (MB) as PS species in organic and aqueous mediums. Subsequently, the capacity of zinc oxide
(ZnO), zinc sulfide (ZnS), and ZnO/ZnS core-shell QDs as well as manganese (Mn+ 2) doped ZnO and ZnS
nanoparticles (NPs) as potential PS was also investigated. Many variable parameters such as type of quencher,
PSs, NPs, as well as its different concentrations, light source, excitation wavelength, reaction time, distance
from light source, and nature of solvent were used. The degradation kinetics of the quenchers generated by SO
species and the corresponding quantum yields were determined by monitoring the photo-oxidation of the
chemical quencher and measuring its disappearance by fluorometry and spectrophotometry in the presence of
NPs. Small intracellular changes of SO induced by these metal Zn (zinc) NPs and PDT could execute and
accelerate deadly programs in these leukemic cells, providing in this way an innovative modality of treatment.
In order to perform further more specific in vitro cytotoxic studies on B-chronic lymphocytic leukemia cells
exposed to Zn NPs and PDT, we needed first to measure and ascertain those possible intracellular SO variations
generated by this type of treatment; for this purpose, we have also developed and tested a novel method first
described by us.