Functionalized silicon quantum dots tailored for targeted siRNA delivery.
For RNA interference (RNAi) mediated silencing of the ABCB1 gene in Caco-2 cells biocompatible luminescent silicon quantum dots (SiQDs) were developed to serve as self-tracking transfection tool for ABCB1 siRNA. While the 2-3nm sized SiQD core exhibits green luminescence, the QD surfaces are completely saturated with covalently linked 2-vinylpyridine that may electrostatically bind siRNA. For down-regulating P-glycoprotein (Pgp) expression of the ABCB1 gene the SiQDs were complexed with siRNA. The cellular uptake and allocation of SiQD-siRNA complexes in Caco-2 cells were monitored using confocal laser scanning microscopy and transmission electron microscopy. The release of siRNA to the cytoplasm was verified through real-time PCR quantification of the reduced ABCB1 mRNA level. Additional evidence was obtained from time-resolved in situ fluorescence spectroscopic monitoring of the Pgp efflux dynamics in transfected Caco-2 cells which yielded significantly reduced transporter efficiencies for the Pgp substrate Rhodamine 123.
Klein
S
S
Department Chemistry and Pharmacy, Physical Chemistry I and ICMM, Friedrich-Alexander University of Erlangen-Nuremberg, Egerlandstrasse 3, Erlangen, Germany.
Zolk
O
O
Fromm
M F
MF
Schrödl
F
F
Neuhuber
W
W
Kryschi
C
C
D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors* / Q000235:genetics; D018938:Caco-2 Cells; D055785:Gene Knockdown Techniques; D006801:Humans; D049449:Luminescence; D045663:Quantum Dots; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism; D012825:Silicon / Q000737:chemistry*; D014162:Transfection
C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D034741:RNA, Small Interfering; D012825:Silicon