Biomedical Engineering Reference
In-Depth Information
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Fig. 19 2-Photons PS (Reproduced by permission of The Royal Society of Chemistry)
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Fig. 20 9,10-Bis (4¢-(4″-aminostyryl)styryl)anthracene (BDSA) (Reproduced by permission of
The Royal Society of Chemistry)
excitation at 532 nm in D 2 O, the characteristic 1 O 2 emission at 1,270 nm was
observed under photoexcitation of the dispersion of nanoparticles co-encapsulating
HPPH and BDSA. For the two-photon sensitization of 1 O 2 in water, ADPA was
used and the authors could also observe the formation of 1 O 2 .
Hela cells were treated with the nanoparticles and two-photon laser scanning
microscopic images revealed an intense fluorescence signal from the cytoplasm.
The intracellular FRET efficiency was estimated up to 36%. Drastic changes of the
morphology of the treated cells were observed in relation to the formation of 1 O 2
after two-photon excitation. As a conclusion, this new concept of two-photon
induced intra-particle FRET offers a simple and proper methodology for develop-
ing formulations with better photophysical properties.
Febvay et al. ( 2010 ) described a drug delivery system where light-activated dis-
ruption of intracellular vesicles occurs after internalization of biofunctionalized
mesoporous silica nanoparticles loaded with fluorescent dye Alexia 456 as cargo.
Size-tunable monodispersed MSN have been functionalized with streptavidin via
PEG spacer arms in order to target cancer cells expressing P-glycoprotein, a trans-
porter protein responsible for multidrug resistance in many tumours. These MSN
 
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