Synergistic Chemo-Photothermal Suppression of Cancer by Melanin Decorated MoO_x Nanosheets

Abstract

Two-dimensional (2D) nanomaterials able to effectively absorb near-infrared (NIR) radiation have shown considerable potential as multifunctional platforms in the treatment of cancer. Here we report a molybdenum dioxide (MoOx)-based system for synergistic chemo-and photothermal therapy of cancer. MoOx nanosheets were generated via a one-step hydrothermal route, grafted with polyethylene glycol (PEG), and decorated with melanin (Mel), with successful functionalization confirmed by IR spectroscopy. The mean diameter and thickness of the MoOx particles are found to be 302 ± 34 nm and 19 ± 2 nm using atomic force microscopy. The hydrodynamic size of the MoOx nanosheets was 105 ± 17 nm, and the final MoOx-PEG-Mel-DOX formulation had a diameter of 161 ± 26 nm). The MoOx-PEG-Mel nanosheets efficiently convert NIR light to heat, possessing a photothermal conversion efficiency of 61.7%. They can also be loaded with doxorubicin (DOX), giving a high drug loading (325.6 mg DOX / g MoOx-PEG-Mel). MoOx-PEG-Mel-DOX shows DOX release influenced by pH and NIR irradiation. Systematic in vitro and in vivo evaluations reveal that synergistic chemo-and photothermal therapy using MoOx-PEG-Mel-DOX can completely eradicate a tumor, with no observable off-target cytotoxicity. This is the first report of the fabrication of enhanced photothermal agents by combining MoOx nanosheets and a natural product. This work proffers a strategy for efficiently treating cancer, as well as potentially extending the photothermal applications of 2D nanomaterials by surface melanin functionalisation.

Morphology‐controlled Synthesis of Molybdenum Oxide with Tunable Plasmon Absorption for Phothermal Therapy of Cancer

“…[38,39] Thus, the MoO 3-x nanomaterials were applied in photothermal removal of cancer. [40][41][42] The convenient way to obtain MoO 3-x nanomaterials is to separate from bulk oxide [17] MoO 3 powders with an exfoliation process, which is time consuming and low yield. Generally, the extraction of MoO 3-x nanoparticles can be classified as two categories: hydrothermal and chemical exfoliation.…”

“…But nanosheets obtained have poor hydrophilicity, which need to be modified by polyethylene glycol (PEG) to improve solubility. Xiao et al [41] reported a research work about the synthesis of strong photoluminescence MoO 3-x quantum dots via hydrogen peroxide (H 2 O 2 ) as the oxidant to inserted into molybdenum disulfide (MoS 2 ) powder. Compared with other papers, this method is without an external stimulus.…”

Molybdenum‐Based Nanomaterials for Photothermal Cancer Therapy

“…The hydro/solvothermal synthesis method has been extensively used to prepare molybdenum oxide nanomaterials with different morphologies, such as nanodots (Figure 4A), nanoparticles, nanoribbons, nanosheets, nanospheres, and nanorings. [69,71,72,83,85,105,106,[159][160][161][162][163][164][165][166][167][168][169] As a typical example, Song et al reported the synthesis of molybdenum oxide nanomaterials with controlled morphologies by this method. [85] The mixed solution of (MoO 2 (OH)(OOH)) and PEG was treated in an autoclave at 90 °C for 12 h to obtain molybdenum oxide nanospheres.…”

Functionalized layered double hydroxide nanoparticles as an intelligent nanoplatform for synergistic photothermal therapy and chemotherapy of tumors

“…2D NMs are superior to other nanomaterials in terms of tumor identification drug delivery, and clinical treatment, providing a 3 powerful platform for enhanced medical precision. Common 2D NMs , such as ultra-thin graphene oxide [20], black phosphorus [21] and transition metal dihalides [22] have been used as drug carriers. However, these 2D NMs usually have some disadvantages, such as difficultsynthesis, limited loading capacity or poor biocompatibility, which limits their application in tumor targeted therapy [23].…”

“…In addition to chemotherapy, photothermal therapy (PTT) is also a widely used clinical treatment of cancer and is a novel and promising developing method for cancer treatment [22,38,39]. Compared with other cancer treatments, PTT is noninvasive and highly efficient, [40].…”