The nonradiative conversion of light energy into heat (photothermal therapy, PTT) or sound energy (photoacoustic imaging, PAI) has been intensively investigated for the treatment and diagnosis of cancer, respectively. By taking advantage of nanocarriers, both imaging and therapeutic functions together with enhanced tumour accumulation have been thoroughly studied to improve the pre-clinical efficiency of PAI and PTT. In this review, we first summarize the development of inorganic and organic nano photothermal transduction agents (PTAs) and strategies for improving the PTT outcomes, including applying appropriate laser dosage, guiding the treatment via imaging techniques, developing PTAs with absorption in the second NIR window, increasing photothermal conversion efficiency (PCE), and also increasing the accumulation of PTAs in tumours. Second, we introduce the advantages of combining PTT with other therapies in cancer treatment. Third, the emerging applications of PAI in cancer-related research are exemplified. Finally, the perspectives and challenges of PTT and PAI for combating cancer, especially regarding their clinical translation, are discussed. We believe that PTT and PAI having noteworthy features would become promising next-generation non-invasive cancer theranostic techniques and improve our ability to combat cancers.

/pdf/photothermal-therapy-and-photoacoustic-imaging-via-5cxqag870v.pdf

Photothermal therapy and photoacoustic imaging via nanotheranostics in fighting cancer

Recent progress of chemodynamic therapy-induced combination cancer therapy

Inorganic nanomaterials that have inherently exceptional physicochemical properties (e.g., catalytic, optical, thermal, electrical, or magnetic performance) that can provide desirable functionality (e.g., drug delivery, diagnostics, imaging, or therapy) have considerable potential for application in the field of biomedicine. However, toxicity can be caused by the long-term, non-specific accumulation of these inorganic nanomaterials in healthy tissues, preventing their large-scale clinical utilization. Over the past several decades, the emergence of biodegradable and clearable inorganic nanomaterials has offered the potential to prevent such long-term toxicity. In addition, a comprehensive understanding of the design of such nanomaterials and their metabolic pathways within the body is essential for enabling the expansion of theranostic applications for various diseases and advancing clinical trials. Thus, it is of critical importance to develop biodegradable and clearable inorganic nanomaterials for biomedical applications. This review systematically summarizes the recent progress of biodegradable and clearable inorganic nanomaterials, particularly for application in cancer theranostics and other disease therapies. The future prospects and opportunities in this rapidly growing biomedical field are also discussed. We believe that this timely and comprehensive review will stimulate and guide additional in-depth studies in the area of inorganic nanomedicine, as rapid in vivo clearance and degradation is likely to be a prerequisite for the future clinical translation of inorganic nanomaterials with unique properties and functionality.

Inorganic nanomaterials with rapid clearance for biomedical applications.

Chemodynamic therapy (CDT), a novel cancer therapeutic strategy defined as the treatment using Fenton or Fenton-like reaction to produce •OH in the tumor region, was first proposed by Bu, Shi, and co-workers in 2016. Recently, with the rapid development of Fenton and Fenton-like nanomaterials, CDT has attracted tremendous attention because of its unique advantages: 1) It is tumor-selective with low side effects; 2) the CDT process does not depend on external field stimulation; 3) it can modulate the hypoxic and immunosuppressive tumor microenvironment; 4) the treatment cost of CDT is low. In addition to the Fe-involved CDT strategies, the Fenton-like reaction-mediated CDT strategies have also been proposed, which are based on many other metal elements including copper, manganese, cobalt, titanium, vanadium, palladium, silver, molybdenum, ruthenium, tungsten, cerium, and zinc. Moreover, CDT has been combined with other therapies like chemotherapy, radiotherapy, phototherapy, sonodynamic therapy, and immunotherapy for achieving enhanced anticancer effects. Besides, there have also been studies that extend the application of CDT to the antibacterial field. This review introduces the latest advancements in the nanomaterials-involved CDT from 2018 to the present and proposes the current limitations as well as future research directions in the related field.

Chemodynamic Therapy via Fenton and Fenton-Like Nanomaterials: Strategies and Recent Advances.

Copper single-atom catalysts with photothermal performance and enhanced nanozyme activity for bacteria-infected wound therapy.

Liquid exfoliation of TiN nanodots as novel sonosensitizers for photothermal-enhanced sonodynamic therapy against cancer

Biodegradable Nickel Disulfide Nanozymes with GSH-Depleting Function for High-Efficiency Photothermal-Catalytic Antibacterial Therapy.

Sonodynamic therapy, with advantages in large tissue penetration depth and great controllability, is a promising type of non-invasive cancer treatment method. Developing sonosensitizers with high reactive oxygen species (ROS) quantum yield and the ability to regulate tumor microenvironment to achieve enhanced performances in sonodynamic therapy would thus be rather attractive. Herein, vanadium (V) doped TiO2 (V-TiO2) nanospindles with glutathione-depleting properties are fabricated for enhanced sonodynamic cancer therapy. Due to doping of the V element, the bandgap of V-TiO2 nanospindles is reduced, increasing the efficiency of ultrasound-triggered ROS production compared to that of pure TiO2 nanoparticles. More interestingly, the doping of V also makes V-TiO2 nanospindles an effective Fenton-like agent, which can catalyze the generation of highly toxic hydroxyl radicals (•OH) from endogenous H2O2 in the tumor, thus enabling cancer-killing through chemodynamic therapy. In addition, the V doping also endows V-TiO2 nanospindles with the function of glutathione depletion, further amplifying the oxidative stress generated by chemodynamic-sonodynamic therapy. In vitro cell experiments and in vivo animal experiments demonstrate that V-TiO2 nanospindles can effectively kill cancer by the combined chemodynamic-sonodynamic therapy, significantly improving the tumor treatment outcomes. Importantly, V-TiO2 with the ultrasmall spindle morphology can be quickly excreted from the body, without causing any long-term toxicity. This work illustrates that doping TiO2 with other special elements is a meaningful strategy to fabricate nanostructures with interesting functions useful in biomedicine.

V-TiO2 nanospindles with regulating tumor microenvironment performance for enhanced sonodynamic cancer therapy

In this study, we synthesized hollow mesoporous silica nanoparticles (HMSNs) coated with polydopamine (PDA) and a D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS)-modified hybrid lipid membrane (denoted as HMSNs-PDA@liposome-TPGS) to load doxorubicin (DOX), which achieved the integration of chemotherapy and photothermal therapy (PTT). Dynamic light scattering (DLS), transmission electron microscopy (TEM), N2 adsorption/desorption, Fourier transform infrared spectrometry (FT-IR), and small-angle X-ray scattering (SAXS) were used to show the successful fabrication of the nanocarrier. Simultaneously, in vitro drug release experiments showed the pH/NIR-laser-triggered DOX release profiles, which could enhance the synergistic therapeutic anticancer effect. Hemolysis tests, non-specific protein adsorption tests, and in vivo pharmacokinetics studies exhibited that the HMSNs-PDA@liposome-TPGS had a prolonged blood circulation time and greater hemocompatibility compared with HMSNs-PDA. Cellular uptake experiments demonstrated that HMSNs-PDA@liposome-TPGS had a high cellular uptake efficiency. In vitro and in vivo antitumor efficiency evaluations showed that the HMSNs-PDA@liposome-TPGS + NIR group had a desirable inhibitory activity on tumor growth. In conclusion, HMSNs-PDA@liposome-TPGS successfully achieved the synergistic combination of chemotherapy and photothermal therapy, and is expected to become one of the candidates for the combination of photothermal therapy and chemotherapy antitumor strategies.

/pdf/fabricating-a-pda-liposome-dual-film-coated-hollow-3bjbzj5h.pdf

Xiyu Wang

Papers

Liquid exfoliation of TiN nanodots as novel sonosensitizers for photothermal-enhanced sonodynamic therapy against cancer

Biodegradable Nickel Disulfide Nanozymes with GSH-Depleting Function for High-Efficiency Photothermal-Catalytic Antibacterial Therapy.

V-TiO2 nanospindles with regulating tumor microenvironment performance for enhanced sonodynamic cancer therapy

Fabricating a PDA-Liposome Dual-Film Coated Hollow Mesoporous Silica Nanoplatform for Chemo-Photothermal Synergistic Antitumor Therapy