A potential method for local drug and dye delivery in the ocular vasculature.
Invest Ophthalmol Vis Sci
; 29(7): 1179-83, 1988 Jul.
Article
em En
| MEDLINE
| ID: mdl-3417407
ABSTRACT
We propose a new drug and dye delivery system that would allow repeated release of substances in the ocular vasculature by an externally controlled mechanism. The substances are encapsulated in heat-sensitive liposomes, which are lysed by locally applying a heat pulse produced by an argon laser. The system was tested by investigating the release of carboxyfluorescein encapsulated in the liposomes. The liposome suspension was incubated at 37 degrees or 38.5 degrees C and irradiated at different powers and pulse durations. The amount of dye released was monitored by fluorophotometry and compared with the concentration obtained when the liposomes were lysed at their transition temperature of 41 degrees C. The results showed that 85% of the encapsulated substance can be released. Moreover, a dramatic contrast was observed between the fluorescence before and after the lysis. Presently the energy density is higher than but close to the maximal permissible exposure for humans. The release mechanism with the short laser pulse appeared to be similar to that present when liposomes were heated slowly.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tratamento Farmacológico
/
Corantes
/
Olho
/
Lasers
/
Lipossomos
Idioma:
En
Revista:
Invest Ophthalmol Vis Sci
Ano de publicação:
1988
Tipo de documento:
Article