Figure 4. Schematic Diagram of (a) Synthesis procedure of HA-HNSs and (b) HA-HNSs-Mediated SDT/MPTT for preventing atherosclerotic plaque progression. (c) Magnified images: TEM (i), HAADF-STEM (ii), HRTEM (iii). (d) XRD patterns. *, peaks of TiO2. #, peaks of CuS. (e) Survey XPS. (f) O 1s XPS. (g) UV−vis−NIR absorption spectra of HNSs. Reproduced from Ref. [161] with permission. Copyright 2022 American Chemical Society.
3.3. Organic-inorganic hybrids
3.3.1. Metal–organic frameworks (MOFs)
MOFs is the abbreviation of Metal–organic Framework. It is a kind of crystalline porous material with periodic network structure formed by self-assembly of inorganic metal center (metal ion or metal cluster) and bridged organic ligand. MOFs are organic-inorganic hybrid materials, also known as coordination polymers, which are different from inorganic porous materials and organic complexes in general.[164-166] Both the rigidity of inorganic materials and the flexibility of organic materials. It shows great development potential and attractive development prospect in modern material research. Zhang et al. introduced a versatile nanomaterial based on a Zr-FeP MOF through a simple one-pot hydrothermal method. These Zr-FeP MOF nanoshuttles demonstrate a significant photothermal effect with a high PCE of up to 33.7%. When loaded with HSP70 siRNA and subjected to a single NIR laser irradiation, the Zr-FeP MOF nanoshuttles efficiently suppress tumor growth, both in vitro and in vivo, owing to the synergistic effects of PDT and MPTT. Furthermore, they exhibit excellent capabilities for photothermal imaging, computed tomography (CT), and PAI, enabling precise tumor diagnosis.[167] This research contributes to the development of ”all-in-one” nanoagents that can perform multimodal imaging for accurate tumor diagnosis and deliver synergistic treatments through PDT and MPTT. Li et al. developed a Bi@ZIF-8 (BZ) nanomaterial using a straightforward one-step reduction method. They then efficiently loaded GA onto the BZ nanomaterial through physical mixing. The researchers conducted comprehensive characterization of the nanomaterial, including studying the release of GA in response to changes in pH and NIR-light irradiation. The BZ nanomaterial exhibited a significantly improved drug release rate when the temperature was elevated under acidic conditions. It demonstrated excellent stability under laser irradiation and achieved a PCE of approximately 24.4% with good biocompatibility and great potential for use in MPTT, showcasing excellent efficacy in tumor destruction.[168] Chang et al. encapsulated Pd NPs within ZIF-8 to create Pd@ZIF-8 composites. They introduced an innovative strategy for ferroptosis-boosted MPTT based on a single-atom nanozyme (SAzyme). This Pd SAzyme, characterized by its atom-efficient utilization of catalytic centers, exhibits peroxidase (POD) and glutathione oxidase (GSHOx) mimicking activities, as well as efficient photothermal conversion performance. These attributes contribute to the induction of ferroptosis, characterized by the up-regulation of lipid peroxides (LPO) and ROS. The accumulation of LPO and ROS resulting from the Pd SAzyme’s activity provides a potent means for cleaving HSPs, enabling Pd SAzyme-mediated mild temperature generation.[169] They further employed Cu SAzyme, which possesses exceptional multi-enzyme activities capable of triggering the formation of a ROS storm. This ROS storm has the potential to inflict damage on the existing HSPs within cancer cells. By combining a dual-pronged strategy involving a SGLT inhibitor and the ROS storm, the Cu SAzyme loaded with LIK066 demonstrates high efficiency in eliminating HSPs, thereby achieving MPTT.[170] Feng et al. developed an innovative Au-Fe SAzyme nanosystem that enables highly efficient simultaneous photothermal, photodynamic, and chemodynamic therapy in NIR range. The photothermal treatment effect of the Au-Fe SAzyme nanosystem is particularly notable. Importantly, this nanosystem possesses glucose oxidase (GOD)-like abilities, leading to significant inhibition of glucose metabolism at the tumor site and down-regulation of HSPs expression.[171] These results highlighted the potential of the Au-Fe SAzyme nanosystem as a novel photothermal reagent that overcomes the limitations of traditional photosensitizers. The SAzyme platform also provides insights for the development of other types of MPTT, addressing current limitations in photothermal treatment. Peng et al. developed a nanoplatform consisting of ZIF-8 coated mesoporous polydopamine (MPDA) core–shell NPs, which were then loaded with Pifithrin-μ (PES, a natural inhibitor of HSPs). The ZIF-8 shell of the MPDA@ZIF-8/PES nanoplatform exhibited rapid degradation in response to the acidic environment typically found in bacterial biofilm infections. This triggered the controlled release of PES and Zn ions. Consequently, the suppression of HSP was notably effective, enhancing the efficacy of MPTT. Additionally, the release of Zn2+ exhibited antibacterial and antibiofilm effects.[172] Thus, the fabricated nanosystem was capable of effectively eliminating bacterial biofilms, achieving MPTT at around 45°C, and demonstrating excellent antibacterial efficacy. These studies not only offer simple approach for creating the nanosystem responsive to the biosystem but also introduce a promising strategy for MPTT.