Enhancement of hematoporphyrin IX potential for photodynamic therapy by entrapment in silica nanospheres.
Phys Chem Chem Phys
; 13(33): 14946-52, 2011 Sep 07.
Article
em En
| MEDLINE
| ID: mdl-21769362
The entrapment of hematoporphyrin IX (Hp IX) in silica by means of a microemulsion resulted in silica spheres of 33 ± 6 nm. The small size, narrow size distribution and lack of aggregation maintain Hp IX silica nanospheres stable in aqueous solutions for long periods and permit a detailed study of the entrapped drug by different techniques. Hp IX entrapped in the silica matrix is accessed by oxygen and upon irradiation generates singlet oxygen which diffuses very efficiently to the outside solution. The Hp IX entrapped in the silica matrix is also reached by iron(II) ions, which causes quenching of the porphyrin fluorescence emission. The silica matrix also provides extra protection to the photosensitizer against interaction with BSA and ascorbic acid, which are known to cause suppression of singlet oxygen generation by the Hp IX free in solution. Therefore, the incorporation of Hp IX molecules into silica nanospheres increased the potential of the photosensitizer to perform photodynamic therapy.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fotoquimioterapia
/
Fármacos Fotossensibilizantes
/
Dióxido de Silício
/
Nanosferas
/
Hematoporfirinas
Idioma:
En
Revista:
Phys Chem Chem Phys
Assunto da revista:
BIOFISICA
/
QUIMICA
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Reino Unido