NIR-light-induced surface-enhanced Raman scattering for detection and photothermal/photodynamic therapy of cancer cells using methylene blue-embedded gold nanorod@SiO2 nanocomposites

Abstract

Methylene blue-loaded gold nanorod@SiO2 (MB-GNR@SiO2) core@shell nanoparticles are synthesized for use in cancer imaging and photothermal/photodynamic dual therapy. For the preparation of GNR@SiO2 nanoparticles, we found that the silica coating rate of hexadecylcetyltrimethylammonium bromide (CTAB)-capped GNRs is much slower than that of PEGylated GNRs due to the densely coated CTAB bilayer. Encapsulated MB molecules have both monomer and dimer forms that result in an increase in the photosensitizing effect through different photochemical pathways. As a consequence of the excellent plasmonic properties of GNRs at near-infrared (NIR) light, the embedded MB molecules showed NIR light-induced SERS performance with a Raman enhancement factor of 3.0 × 1010, which is enough for the detection of a single cancer cell. Moreover, the MB-GNR@SiO2 nanoparticles exhibit a synergistic effect of photodynamic and photothermal therapies of cancer under single-wavelength NIR laser irradiation.

Plasmonic photothermal cancer therapy with gold nanorods/reduced graphene oxide core/shell nanocomposites

“…In many reported studies, the intensity of the laser exceeded 1 W cm −2 , 8,[24][25][26] and it is only more recently that more attention has been paid to this parameter. 7,[27][28][29] Bimodal PTT and photodynamic cancer treatments are one way to overcome this limitation. 7 The development of novel gold nanostructures and hybrids with a more efficient light-to-heat conversion is the other option.…”

“…7 The development of novel gold nanostructures and hybrids with a more efficient light-to-heat conversion is the other option. 27,28,30 The wrapping and embedding of gold nanostructures within graphene oxide (GO) and reduced graphene oxide (rGO) could be a way into this direction. [31][32][33] Kohane and coworkers showed that rGO coated gold nanoparticles kill cells more rapidly under 808 nm irradiation with a laser intensity of 3 W cm −2 , than did uncoated particles.…”

Gold nanoparticles for cancer theranostics — A brief update

“…AuNPs mediated PPT has been used widely as a preliminary treatment to melanoma, epithelial, breast and colon cancer cells both in vitro and in vivo. [31][32][33] Controlled surface engineering of AuNPs using ligands of tumor biomarkers and HIV Tat 49-57 which has a membrane translocation domain and a nuclear localization sequence have been successfully used to irreparably damage DNA of cancer cells via directly heating their nucleus through PPT. 34 In addition, noninvasive radiofrequency¯eld (RF,…”

Copper sulfide nanoparticles: from synthesis to biomedical applications

“…Compared with conventional agents, NP-based imaging probes provide several advantages [40], including enhanced circulation halflife, the integration of "smart sensing" properties to the probes [41], and the ability to load both imaging and drug components in one vehicle for multifunctional applications [42]. Generally speaking, molecular imaging includes the use of optical techniques such as bioluminescence and fluorescence imaging [43], molecular magnetic resonance imaging (MRI) [44], magnetic resonance spectroscopy (MRS), positron emission tomography (PET) [45], single-photon emission computed tomography (SPECT) [46], and increasingly popular photoacoustic tomography (PAT) [40]. [12].…”