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Especies activas de oxígeno generadas a partir de fullereno fotoexcitado (C60) como medicamentos potenciales: O2-*
Yoko Yamakoshi1, Naoki Umezawa, Akemi Ryu
1Division of Organic Chemistry, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya, Tokyo 158-8501, Japan. yamakosh@nihs.go.jp
Journal of the American Chemical Society
|October 16, 2003
Resumen
Los fullerenos como el C60 actúan como fotosensibilizadores, generando especies reactivas de oxígeno. En condiciones biológicas, estos incluyen principalmente radicales aniónicos superóxido y radicales hidroxilo, que causan daño al ADN.
Área de la Ciencia:
- La fotoquímica es la fotoquímica.
- La bioquímica es la bioquímica.
- Los nanomateriales son nanomateriales.
Sus antecedentes:
- Los fullerenos (C60 y C70) son nanopartículas con aplicaciones potenciales en sistemas biológicos.
- Los fotosensibilizadores generan especies reactivas de oxígeno (ROS) tras la exposición a la luz.
- Comprender la generación de ROS es crucial para evaluar la seguridad y eficacia del fullereno.
Objetivo del estudio:
- Para caracterizar la fotosensibilización de los fullerenos (C60 y C70) en contextos biológicos.
- Para identificar las especies específicas de oxígeno activo generadas por los fullerenos en diferentes condiciones.
- Para determinar el papel de estas especies en la escisión del ADN fotoinducida.
Principales métodos:
- Pruebas bioquímicas (escisión del ADN con carroñeros).
- Métodos físico-químicos (atrapamiento de radicales EPR, espectrometría del infrarrojo cercano).
- Métodos químicos (ensayo de tetrazolio azul nitro).
Principales resultados:
- C60 generó oxígeno (1O2) en disolventes no polares.
- En disolventes polares (como el agua) y con reductores (como el NADH), el C60 produjo radicales aniónicos superóxido (O2(-) *) y radicales hidroxilo (*OH) en lugar de (1O2).
- Los ensayos de escisión del ADN confirmaron que O2(-)* y *OH eran responsables del daño al ADN fotoinducido por C60 en condiciones fisiológicas.
Conclusiones:
- Los mecanismos de fotosensibilización del fullereno difieren significativamente entre los entornos no polares y polares.
- Bajo condiciones fisiológicas, los fullerenos generan principalmente dañinos ROS reducidos (O2(-) *, *OH).
- Estos hallazgos son críticos para evaluar el impacto biológico y el potencial terapéutico de los fullerenos.
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