Metal Sulfide Nanoparticles for Imaging and Phototherapeutic Applications

Abstract

The intriguing properties of metal sulfide nanoparticles (=MxSy-NPs), particularly transition metal dichalcogenides, are discussed for their use in diverse biological applications. Herein, recent advances in MxSy-NPs-based imaging (MRI, CT, optical and photoacoustic) and phototherapy (photothermal and photodynamic) are presented. Also, recent made progress in the use of immuno-phototherapy combinatorial approaches in vitro and in vivo are reported. Furthermore, challenges in nanomaterials-based therapies and future research directions by applying MxSy-NPs in combinatorial therapies are envisaged.

Keywords: bioimaging; immunotherapy; metal sulfide nanoparticles; photodynamic therapy; photothermal therapy.

Figure 1

Representative images of (A) MR imaging and (B) its quantitative estimation. Reprinted with permission from Ref. [22]. Copyright © 2023, Elsevier.

Figure 2

(A) In vitro CT performance of Bi₂S₃@MSNs in comparison with commercially available iobitridol. Inset: Suspensions of Bi₂S₃@MSNs and iobitridol at different concentrations showing CT contrast. (B) Representative CT images of UMR-106 tumor-bearing nude mice showing contrast provided by RGD–Bi₂S₃@MSN and Bi₂S₃@MSN captured 2 and 24 h post-treatment. The red circle highlights the tumor site. Reprinted with permission from Ref. [35]. Copyright © 2023 Wiley.

Figure 3

Representative images of NIR-II fluorescence imaging in BALB/c mice. (A) Full body distribution and (B) zoomed in image showing fluorescence from the femoral artery post-i.v. injection of Ag₂S QDs. [Reprinted with permission from Ref. [43]. Copyright © 2023, Royal Society of Chemistry]. (C) Higher fluorescence intensity observed from the Eppendorf tube containing the same concentration of alloy QDs as compared to MQDs. (D) Cell number dependent increase in fluorescence intensity observed in HeLa cells treated with alloy QDs as compared to MQDs. (E) Higher fluorescence intensity observed in vivo in mice treated with alloy QDs. (F) Images of liver captured 1 h post-treatment showed higher fluorescence in mice treated with alloy QDs. Reprinted with permission from Ref. [44]. Adopted from BioMed Central 2022.

Figure 4

(A) 4T1 tumor bearing mice used for in vivo PAI. Laser scan section has been marked with a dotted circle. (B) Representative PA images taken before and after GSH-CuS NDs i.v. or i.t. injection Reprinted with permission from Ref. [52]. Copyright © 2023, Royal Society of Chemistry. (C) Representative images of PAI and (D) its quantitative estimation pre- and post- administration of FeS QDs at different time points. Tumor area has been demarcated with a white circle in (B,C). Reprinted with permission from Ref. [22]. Copyright © 2023, Elsevier.

Figure 5

Microphotographs of HeLa cells with CuS-NPs. (A) without laser, cells were viable and had polygonal morphology. (B) with NIR laser irradiation at 24 W cm⁻² for 5 min (purple arrows show shrinking of cells; yellow arrows show loss of cell viability by calcein-negative staining; white arrows show loss of cell membrane integrity by EthD-1 positive staining. (C) In vivo PTT in 4T1 tumor bearing mice with saline (top row), WS₂-PEG (middle row: i.t. low dose = 2 mg kg⁻¹), WS₂-PEG (bottom row: i.t. high dose = 20 mg kg⁻¹). The laser power density was 0.8 W cm⁻². Reprinted with permission from Refs. [64,68]. Copyright © 2023, Future Medicine and 2014, Wiley.

Figure 6

(A) Representative fluorescence images of BSA-MoS₂ treated tumor-bearing mice at different time points. (B) In vitro PAT imaging for different concentrations of BSA-MoS₂. (C) Representative PAT images of BSA-MoS₂ treated tumor-bearing mice at different time points with tumor area marked with a white dotted line. (D) Representative infrared images showing thermal profile of tumor-bearing mice treated with BSA-MoS₂ or PBS (control group) and their corresponding (E) temperature profile and (F) tumor volume. (G) Representative pictures of mice showing reduction in tumor size with respective treatments. (H) MR images of mice treated with BSA-MoS₂ before and post- treatment on the 14th day and corresponding (I) changes in body weight. Reprinted with permission from Ref. [88]. Copyright © 2023, Royal Society of Chemistry.