Methylene blue-loaded gold nanobipyramids @SiO_2 enhanced singlet oxygen generation for phototherapy of cancer cells

Synthesis of Mesoporous Silica Coated Gold Nanorods Loaded with Methylene Blue and Its Potentials in Antibacterial Applications

“…After the loading and purification process, the LSPR showed a red-shift to 668 nm (Figure 4). It can be explained by the sensitivity of the AuNRs to the medium's refractive index, in agreement with previous reports, where the LSPR also were red-shifted after the internalization of MB [20]. To avoid the diffusion of an entrapped drug in the solution during storage periods, AuNRs@Simes-MB was subject to lyophilization, applying freeze-dry techniques.…”

“…It protects the MB molecules against photodegradation under the high absorption cross-section of the AuNRs [21]. Furthermore, under overlapping laser irradiation conditions with LSRPlong bands in AuNRs, an increase in the 1 O 2 generation has also been reported [20,21], and it is expected to improve the performance in photothermal processes [22,23].…”

“…Methylene blue (MB) is a cationic water-soluble photosensitizer (PS) that presents a high quantum yield of singlet oxygen ( 1 O 2 ) generation and has been considered as a photodynamic agent in different clinical applications [14,15]. MB has been used in photodynamic antimicrobial applications [16][17][18] as well as loading or grafting on silica-coated gold nanostructures (rods or pyramids), with applications in cancer cell photodynamic therapy (PDT) [9,19,20]. However, MB has the drawbacks of poor photostability and enzymatic degradation.…”

Adjuvant Photothermal Therapy Inhibits Local Recurrences after Breast-Conserving Surgery with Little Skin Damage

“…Herein, we report the application of PEGylated gold nanobipyramids (GBP-PEG) in adjuvant photothermal therapy (aPTT) followed BCS in an orthotopic breast cancer mice model. The production of gold nanobipyramids (GBPs) with high purity is realized by synthetic approaches very recently. − Previous reports showed GBPs have stronger and narrower localized surface plasmonic resonance (LSPR) than other shapes of gold nanoparticles, , thus they are supposed to convert light energy into heat more efficiently. Our results showed that the obtained GBP-PEG had superior photothermal conversion efficacy over that of nanorods.…”

PLGA-coated methylene blue nanoparticles for photoacoustic imaging and photodynamic/photothermal cascaded precisely synergistic therapy of tumor

“… 12 This PS has exhibited great antitumor capabilities under the exposure to 660 nm and 808 nm lasers. However, there were few studies on the photothermal properties of MB nanoparticles, such as PPy–MB NPs 13 and GBPs@SiO 2 -MB 14 nanoplatforms synthesized in 2017, MDA-MB-468 investigated by V. P. S. Jesus et al in 2018, 15 and GO-MB/PF127, in which the photothermal properties of only GO-MB/PF127 and PPy–MB NPs were reported. Also, MB has the drawbacks of poor photo-stability and enzymatic degradation 16 due to the aggregation-caused quenching (ACQ) effect.…”