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

Abstract

Phototheranostics, which is the application of light in the diagnostic imaging and therapy of cancer, has shown great promise for multimodal cancer imaging and effective therapy. Herein, we developed multifunctional gold nanorod@silica-carbon dots (GNR@SiO2-CDs) as a phototheranostic agent by incorporating carbon dots (CDs) with gold nanorods (GNRs), using SiO2 as a scaffold. In GNR@SiO2-CDs, the GNRs act as both photoacoustic (PA) imaging and photothermal therapy (PTT) agents, and the CDs serve as fluorescence (FL) imaging and photodynamic therapy (PDT) agents. The introduction of SiO2 not only improves the chemical stability of the GNRs and CDs in the physiological environment but also prevents the absolute quenching of the fluorescence of the CDs by GNRs. These collective properties make GNR@SiO2-CDs a novel phototheranostic agent, in which high sensitivity and good spatial resolution of FL/PA imaging can be achieved to guide PDT/PTT treatments through i.v. administration. The combination of PDT and PTT proved to be more efficient in killing cancer cells compared to PDT or PTT alone under a low dose of laser irradiation (≤0.5 W cm(-2)). Furthermore, GNR@SiO2-CDs could be cleared out from the body of mice, indicating the low toxicity of this phototheranostic agent. Our work highlights the potential of using GNRs and CDs as novel phototheranostic agents for multifunctional cancer therapies.

Recent advance of carbon dots in bio-related applications

“…The combination of PDT and PTT proved to be more efficient to kill cancer cells. [150] (Continued.) complexes, which chemically bonded on the CDs surface.…”

“…Gold nanorods also exhibit excellent photothermal behaviors with the potential of serving as PTT and photoacoustic (PA) agent. Jia et al [150] constructed a photo theragnostic agent based on gold nanorod@SiO 2 -CDs by introducing a thin layer of SiO 2 between Au nanorods and CDs ( figure 11). The SiO 2 layer has two functions: improving the stability of the Au nanorods and avoiding the fluorescence quenching of CDs.…”

“…The CuCDs nanosheets exhibited laser-triggered cytosolic delivery, lysosomal escape and nuclear-targeting nature. To enhance the cellular uptake or the EPR, Hou et al [183] conjugated the carboxylate CDs with PLGA-b-PEG-NH 2 through growth curves (n = 5) observed after different treatments (n = 5, P < 0.05 for each group); (g) the relative body weights of the nude mice increased continuously after different treatments; (h) representative photographs of the four groups after different treatments; (i) H&E stained images of tumors of the four groups after different treatments [150]. Reproduced from [11] with permission of The Royal Society of Chemistry.…”

Upconverting Carbon Nanodots from Ethylenediaminetetraacetic Acid (EDTA) as Near‐Infrared Activated Phototheranostic Agents

“…An umber of recent studies have successfully reported the use of these carbogenic nanostructures as dual-mode imaging and PDT agents, mostly referred to graphene-like dots or functionalized nanodiamonds. [1,4,[14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] Herein, we report the use of CNDs synthesized by the hydrothermal carbonization (HTC) of ethylenediaminetetraacetic acid (EDTA) at 260 8C( see Experimental Sectionf or furtherd etails). Thism olecular precursorh as been selected to induce the direct generation of nitrogen-doped carbon nanodots (N-CNDs) in as ingle step without the need for secondary amine co-reactants.…”

Advanced Near‐Infrared Light‐Responsive Nanomaterials as Therapeutic Platforms for Cancer Therapy

“…Reproduced with permission [167]. B) Schematic illustration of GNR@SiO 2 -CDs nanocomplex applications in PA imaging, PTT, and PDT for cancer treatment.…”