WS₂ nanosheet as a new photosensitizer carrier for combined photodynamic and photothermal therapy of cancer cells

Abstract

We have developed a simple and efficient strategy to fabricate WS2 nanosheets with low toxicity and good water solubility via a liquid exfoliation method by using H2SO4 intercalation and ultrasonication. The as-prepared WS2 nanosheets were employed not only as an NIR absorbing agent for photothermal therapy (PTT) but also as a photosensitizer (PS) carrier for photodynamic therapy (PDT) due to their sheet like structure that offers large surface area to load PS molecules. Moreover, singlet-oxygen generation of the PSs-WS2 complex could be finely controlled by NIR irradiation that could manipulate the PSs release behavior from WS2 nanosheets. The synergistic anti-tumor effect of WS2 nanosheets mediated PDT-PTT was also evaluated carefully and the results clearly showed that the efficacy of combined PDT-PTT treatment of cancer cells is significantly higher than those of PDT-only and PTT-only treatment, indicating enhanced efficiency of the combined therapeutic system. In addition, the WS2 could be used as a computed tomography (CT) contrast agent for bio-imaging since W atoms have strong X-ray attenuation ability, making them a multifunctional theranostic platform for simultaneous imaging-guided diagnosis and therapy.

Two-Dimensional Colloidal Nanocrystals

“…278 Thanks to their broad light absorption in the visible and near-infrared regions of the spectrum, TMDC nanosheets have been first used as photothermal therapy agents. 283,284 Further studies have also demonstrated their potential as drugs delivery agents, 285,286 using their large surface area to load active molecules. Using direct synthesis pathways, metal-doped WS2 have been prepared to combine magnetic resonance imaging (contrast from the dopant) with X-ray imaging (high Zelements forming the nanosheet).…”

Co9Se8 Nanoplates as a New Theranostic Platform for Photoacoustic/Magnetic Resonance Dual‐Modal‐Imaging‐Guided Chemo‐Photothermal Combination Therapy

“…[22] It has also been reported that anticancer drugs can be released from NIR absorbable nanocarriers triggered by laser irradiation because the local hyperthermia could induce increased thermal vibration of polymer chains and weaken the interactions between the drugs and the nanocarriers. [23] We thus measured the DOX release profile with and without NIR laser irradiation for 5 min (808 nm, 1 W cm −2 ). The data in Figure S5 (Supporting Information) revealed that the NIR irradiation can accelerate the release speed of DOX in the first two hours at pH 5.0.…”

Fabrication of ultrathin Zn(OH)2 nanosheets as drug carriers

“…S8). Given their two-dimensional nature, 22 we assumed that the large contact area and multivalent effect of the PNs would enhance binding ability, consequently endowing SPNs with a high potential for application in targeted drug delivery.…”