Folic acid-conjugated silica-coated gold nanorods and quantum dots for dual-modality CT and fluorescence imaging and photothermal therapy

Abstract

Multifunctional nanoparticles (NPs) have great potential for multimodal cancer imaging and effective therapy. We have developed multifunctional NPs (GNR@SiO 2 @QDs) by incorporating gold nanorods (GNRs) and CdSe/ZnS quantum dots (QDs) into silica. Folic acid (FA) as a targeting ligand was covalently conjugated on the surfaces of GNR@SiO 2 @QDs with a silane coupling agent. Cell viability assay showed that these NPs had low cytotoxicity. And confocal fluorescence images illustrated that they could selectively target HeLa cells overexpressing folate receptors (FRs) rather than FR-deficient A549 cells. In vitro cell imaging experiments revealed that these NPs exhibited strong X-ray attenuation for X-ray computed tomography (CT) imaging and strong fluorescence for fluorescence imaging. They also showed an enhanced photothermal therapy (PTT) effect for cancer cells due to GNRs' high absorption coefficient in the near infrared (NIR) region and a better heat generation rate. All results show that they have great potential in theranostic applications such as for targeted tumor imaging and therapy.

Folic acid-conjugated chromium(III) doped nanoparticles consisting of mixed oxides of zinc, gallium and tin, and possessing near-infrared and long persistent phosphorescence for targeted imaging of cancer cells

“…3b). The FT-IR spectra of amination-ZGSC main consisted of several characteristic strong absorption bands, including 1020 and 1134 cm −1 band, attributed to the stretching vibrations of O-Si-O [18], 2879 and 2945 cm −1 band, assigned to the asymmetric and symmetric CH 2 -stretching bands [15], and 3288 cm −1 band, related to the N-H stretching bands [14]. These additional absorption bands successfully indicate the amination-modification of ZGSC nanoparticles.…”

“…Moreover, FA has the advantages of low cost, nonimmunogenic character and ability to conjugate with a wide variety of nanomaterials [8]. To date, the suggested NIR folate-based tracers mainly consist of organic dyes, inorganic semiconducting quantum dots, up and down-conversion luminescent nanoparticles, and noble metal nanoparticles [5,6,[9][10][11][12][13][14][15][16]. Parts of them have been therapeutically and diagnostically exploited and applied as anti-FR antibodies, high-affinity antifolates, folate-based imaging agents and folate-conjugated drugs and toxins [17,18].…”

Gold nanorod@silica-carbon dots as multifunctional phototheranostics for fluorescence and photoacoustic imaging-guided synergistic photodynamic/photothermal therapy

“…56,57 All these results suggest that the GNR@SiO2-CDs with negative charge on the surface were successfully prepared. …”

NIR‐Responsive Polycationic Gatekeeper‐Cloaked Hetero‐Nanoparticles for Multimodal Imaging‐Guided Triple‐Combination Therapy of Cancer

“…Due to their photostablility and high emission intensity, quantum dots (QDs) were widely integrated with other functional nanoparticles to increase the diagnostic sensitivity and feasibility . To avoid fluorescence quenching caused by direct contact of QDs with Au NRs through energy transfer, a layer of mesoporous silica is the intriguing candidate to insulate Au NRs and QDs . In addition, it should be noted that mesoporous silica also possesses excellent capacity of drug loading .…”