Photothermal remedy (PTT) has emerged as a promising different to conventional most cancers remedy modalities, due to its glorious therapeutic efficacy and minimal invasiveness [1], [2], [3]. The primary near-infrared (NIR-I) biowindow (650–900 nm) is mostly utilized in PTT [4], [5], [6], which options intrinsic benefits of diminished pores and skin absorbance and deep tissue penetration [7], [8], [9]. By changing NIR-I mild power into warmth, PTT can induce fast temperature elevation within the tumors (>50 °C), ensuing within the destruction of DNA, disruption of cell membranes, denaturation of proteins, and eventually tumor tissue ablation [10], [11], [12], [13], [14]. In the meantime, PTT can induce immunogenic cell loss of life (ICD) of tumor cells, accompanied by the discharge of tumor-associated antigens (TAAs) and damage-associated molecular patterns (DAMPs) that additional promote the maturation of dendritic cells (DCs) [15]. The matured DCs then provoke the differentiation and infiltration of T cells to ablate the tumors [16], [17], [18], [19]. As well as, PTT facilitates the polarization of macrophages towards the M1-like phenotype [20], [21], and reduces the abundance of regulatory cells (Tregs) [22], [23], [24], thereby assuaging immunosuppression inside the tumor microenvironment.
The photothermal conversion effectivity (PCE), biocompatibility, and in vivo stability of photothermal nanoagents (PTNAs) are important for PTT. Over latest many years, varied PTNAs have been efficiently synthesized, together with metal-based [25], [26], [27], steel chalcogenide-based [28], [29], [30], steel oxide-based [31], carbon-based [32], and natural [33], [34], [35] PTNAs. Amongst them, ternary steel chalcogenide-based PTNAs stand out attributable to their larger extinction coefficient [36], Grüneisen coefficient [37], and lightweight absorption coefficient [38], in addition to negligible non-radiative attenuation effectivity [39], which collectively lead to superior PCE [40], [41], [42]. Whereby, Cu2SnS3 (CTS) composed of cost-effective components displays robust photothermal properties, making it a promising candidate for the event of PTNAs [43]. Nonetheless, restricted biomedical functions have been reported as a result of problem of synthesizing biocompatible and secure CTS nanomaterials [44]. Consequently, improvement of artificial strategies for producing CTS nanomaterials with excessive biocompatibility and in vivo stability is essential for advancing their biomedical functions in PTT.
With the try to immediate the efficient and protected PTT mediated by CTS nanomaterials, we herein synthesized polyvinyl pyrrolidone (PVP)- and ethylene glycol (EG)-modified CTS (PE/CTS) nanoparticles (NPs) and nanosheets (NSs) with glorious biocompatibility and stability by way of the one-pot solvothermal technique. PE/CTS NPs had been recognized and utilized to photothermal immunotherapy as a result of they possessed stronger photothermal most cancers killing functionality and better tumor accumulation in vivo after systemic administration. As thus, PE/CTS NPs mediated efficient PTT to ablate tumor tissues, and concurrently alleviated immunosuppression inside the tumor microenvironment (TME). Moreover, PTT-mediated immunogenicity enhancement evoked systemic immune response to eradicate each main and distant tumors (Scheme 1).
