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Noninvasive treatments for terminal cancer patients constitute a new trend in tumor treatment. Therefore, phototherapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), has attracted considerable interest. Light and a photosensitizer (PS) are employed in both treatment methods. For PDT, the PS generates reactive oxygen species (ROS) when exposed to light, whereas for PTT, the PS generates heat. In this regard, the systematic design of new PSs has become an active area of phototherapy research in an effort to solve the problems associated with conventional PSs. In the past decade, activatable and heavy‐atom‐free PSs have become significant research areas. Therefore, we discuss our recent contributions to the PDT and PTT in this account. [ABSTRACT FROM AUTHOR]

Antibiotic‐independent artificial nanozymes exhibit excellent biocatalytic activity, and can generate sufficient reactive oxygen species (ROS) for potential applications in the field of anti‐infective therapy. However, single nanozymes often catalyze the production of ROS with low yield and low utilization, resulting in low antibacterial activity. To address the above refractory concern, a spike‐like surface nanoparticles (CAC NPs) platform is built that possesses intrinsic dual enzyme‐like (oxidase and peroxidase‐like) activities and photothermal conversion capacity with near‐infrared irradiation (NIR‐I) to quickly capture and effectively eliminate the bacteria and biofilm. Upon NIR‐I irradiation, CAC NPs have exerted an excellent biocatalytic antibacterial effect through a hyperthermia‐amplified dual enzyme‐like activities strategy. As predicted, the results show CAC NPs can eradicate bacteria in the subcutaneous tissues of mice and promote the healing of inflamed tissues with no significant side effects in vivo. Collectively, this work reveals the potential of NIR‐assisted dual enzyme‐like activities for antimicrobial therapy and provides broad prospects for antimicrobial drugs and strategies. [ABSTRACT FROM AUTHOR]

Novel BODIPY photosensitizers were developed for imaging‐guided photodynamic therapy. The introduction of a strong electron donor to the BODIPY core through a phenyl linker combined with the twisted arrangement between the donor and the BODIPY acceptor is essential for reducing the energy gap between the lowest singlet excited state and the lowest triplet state (ΔEST), leading to a significant enhancement in the intersystem crossing (ISC) of the BODIPYs. Remarkably, the BDP‐5 with the smallest ΔEST (ca. 0.44 eV) exhibited excellent singlet oxygen generation capabilities in both organic and aqueous solutions. BDP‐5 also displayed bright emission in the far‐red/near‐infrared region in the condensed states. More importantly, both in vitro and in vivo studies demonstrated that BDP‐5 NPs displayed a high potential for photodynamic cancer therapy and bioimaging. [ABSTRACT FROM AUTHOR]

Phototheranostic nanoplatforms are of particular interest for cancer diagnosis and imaging‐guided therapy. Herein, we develop a supramolecular approach to fabricate a nanostructured phototheranostic agent through the direct self‐assembly of two water‐soluble phthalocyanine derivatives, PcS4 and PcN4. The nature of the molecular recognition between PcS4 and PcN4 facilitates the formation of nanostructure (PcS4‐PcN4) and consequently enables the fabrication of PcS4‐PcN4 with completely quenched fluorescence and reduced singlet oxygen generation, leading to the high photoacoustic and photothermal activity of PcS4‐PcN4. In vivo evaluations suggest that PcS4‐PcN4 could not only efficiently visualize a tumor with high contrast through whole‐body photoacoustic imaging but also enable excellent photothermal therapy for cancer. [ABSTRACT FROM AUTHOR]

Theranostic, which integrates the diagnosis and tumor treatment in tandem, is an emerging strategy in cancer treatment. Here, we report a novel and unique theranostic nanoparticle, HBCP NP, based on hexa-BODIPY cyclophosphazene (HBCP). Due to the unique bulky molecular structure of HBCP, this nanoparticle can simultaneously perform near-infrared (NIR) fluorescence imaging and photoacoustic imaging (PAI). Interestingly, since reactive oxygen species (ROS) generation of HBCP NPs is completely inhibited, 'safe' fluorescence imaging is possible without the risk of cell damage even under laser irradiation. Finally, NIR fluorescence imaging and PAI in 4T1 tumor-bearing mice demonstrated selective accumulation of HBCP NPs at tumor sites. In addition, HBCP NPs exhibited excellent photothermal effects under high-power laser irradiation, achieving effective tumor growth inhibition. [Display omitted] • A theranostic nanoparticle based on Hexa-BODIPY Cyclophosphazene (HBCP NP) was reported. • HBCP NPs perform simultaneous near-infrared (NIR) fluorescence imaging and photoacoustic (PA) imaging. • HBCP NPs generate almost no ROS even under low-power lasers, which enables 'safe' fluorescence imaging and phototherapy. • The ∼93 nm size of HBCP NPs allows selective accumulation in tumors through the EPR effect. • HBCP NPs effectively inhibited tumor growth with excellent photothermal properties in tumor-bearing mice. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) and nitrogen species (RNS) are very important in various pathological and physiological processes. In particular, hypochlorous acid/hypochlorite (HOCl/OCl−) is one of the most important reactive oxygen species (ROS), which is endogenously produced from H 2 O 2 and Cl− by myeloperoxidase (MPO) catalysis. HOCl is both beneficial and harmful to living species including humans. HOCl can destroy invasive bacteria as an immune defense system while, on the other hand, it can cause many diseases including cancers due to pathogenic oxidative stress injury. Accordingly, fluorescent imaging probes for HOCl have been actively investigated in recent years. In this review, we cover the recent progress from 2019 to 2021 on small molecule-based fluorescent imaging probes for hypochlorous acid (HOCl)/hypochlorite (OCl−). [Display omitted] • Recent progress on fluorescent probes for hypochlorous acid (HOCl)/hypochlorite (OCl−). • Summary of different reaction types for HClO/OCl−. • Various fluorescence response mechanisms are discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Reaction mechanisms of various types of sulfur-based fluorescent probes with HOCl. • The advantages and disadvantages of sulfur-based fluorescent probes for HOCl. • The applications of sulfur-based fluorescent probes for HOCl. Hypochlorous acid (HOCl) is an endogenously produced reactive oxygen species (ROS), which acts as a protector against microbes. However, its aberrant production is implicated in various oxidative-stress related pathophysiological processes, such as cardiovascular disorders, arthritis, and neurodegenerative diseases. Therefore, the direct, rapid, sensitive, and selective detection of endogenous HOCl in living systems is of essential importance for better understanding the HOCl-involved chemical biology. In the last two decades, sulfur-based fluorescent probes for HOCl have been widely designed and they usually show rapid reaction rate, high selectivity and excellent sensitivity. This review summarized the advances that have been made in the development of sulfur-based fluorescent probes for HOCl, and their reaction mechanisms were emphatically discussed. Lastly, the achievements, challenges, and perspectives in this field were outlooked. [ABSTRACT FROM AUTHOR]

• Recent advances in fluorescent and luminescent probes for ROS and RNS are discussed. • Metal-coordinated ROS- and RNS- selective probe systems are covered. • The categories of this review are H 2 O 2 , •OH, 1O 2 , O 2 •–, HOCl, ONOO−, NO/NO 2 , and HNO. Reactive oxygen species (ROS) are chemically reactive species containing oxygen, which are produced from molecular oxygen (O 2) during vital processes occurring in humans and other living organisms. These species include hydrogen peroxide (H 2 O 2), hypochlorous acid/hypochlorite (HOCl/ClO–), hydroxyl radicals (OH), superoxide anion radicals (O 2 –) and singlet oxygen (1O 2). ROS play key roles in various signaling and pathological processes and are essential to human life, but overproduction of ROS by exogenous stimuli is harmful because ROS can induce oxidation of DNA, proteins or lipids, resulting in cell death. Therefore, unusual ROS levels can indicate ailments such as Parkinson's and Alzheimer's diseases, inflammation, diabetes and cancer. Reactive nitrogen species (RNS) are another group of important chemically reactive species, which can damage cells via nitrosative stress. RNS include nitric oxide (NO), nitroxyl (HNO), nitrogen dioxide (NO 2) and peroxynitrite (ONOO–). Due to their importance in human life, research into fluorescent and luminescent sensing and imaging of these ROS and RNS has been very active over the last couple of decades. Metal ions play key roles in the probes as an on–off redox switch for photoinduced quenching and as a reaction site with ROS, RNS or luminescent cores. Metal coordination reports the presence of analyte by changing the fluorescence intensity, lifetime, or excitation/emission maxima. Redox-active metal ions can be trigger switches that control fluorescence quenching effects, which can be used to sense ROS or RNS. In addition, metal ions, especially lanthanide metal ions, can often be themselves a source of light emission. In this review, we cover ROS- and RNS-selective fluorescent and luminescent probes based on metal-coordinated systems. This review is organized by the target ROS or RNS, which are H 2 O 2 , HOCl/ClO–, OH, O 2 –, 1O 2 , NO, ONOO–, HNO and NO 2. [ABSTRACT FROM AUTHOR]

Phototherapy, which mainly includes photodynamic therapy (PDT) and photothermal therapy (PTT), is a new type of tumor therapy that uses a specific light source to irradiate enriched phototherapy drugs at the tumor site and produce reactive oxygen species or induce a photothermal action to kill the tumor. Human serum albumin (HSA)—the most abundant carrier protein in serum—has diverse binding domains; thus, it can be used as a carrier to bind various photosensitizers and photothermal converting agents (PTCAs) to improve the therapeutic efficacy of PDT and PTT. Compared to traditional tumor therapy, phototherapy administered via HSA delivery has the advantages of strong targeting and less trauma and has been widely studied to date. However, this interesting topic has not yet been systematically reviewed. Herein, we focus on the recent research progress on photosensitizers and PTCAs in HSA-delivered PDT and PTT, including their design and synthesis, tumor-targeting mechanisms, and tumor therapeutic applications. Furthermore, as clinical tumor treatment methods, PDT and PTT still have several drawbacks and limitations, such as the inability to spread to metastatic tumors, the dependence on the dose of photosensitizers and PTCAs, low light tissue penetration, and the requirement to avoid light for patients during treatment. This important review may facilitate the development of enhanced photosensitizers and PTCAs to provide highly powerful research tools for basic medical studies aimed at improving the diagnosis and treatment of clinical cancer. The recent developments of photosensitizers and photothermal converting agents (PTCAs) in HSA -delivered PDT, PTT, and PDT/PTT synergies have been reviewed for the first time. [Display omitted] • Significance of designing photosensitizers and photothermal converting agents (PTCAs) for human serum albumin (HSA)-delivered PDT and PTT. • Design strategies and mechanisms of photosensitizers and PTCAs used in PDT and PTT. • Advantages and limitations of photosensitizers and PTCAs in PDT and PTT. • Perspectives on photosensitizers and PTCAs in phototherapy. [ABSTRACT FROM AUTHOR]

Singlet oxygen is a cytotoxic reactive species which is involved in the photodynamic therapy of cancer. It is also known to be produced endogenously in most eukaryotic cells and implicated in many biochemical processes, including apoptotic response. We now report that Bodipy based fluorescent dyes with singlet oxygen reactive modules, signal the intracellular generation of singlet oxygen through photosensitization. We believe long wavelength probes of singlet oxygen, based on this approach will be highly valuable. Image 1 • Singlet oxygen is a cytotoxic reactive species, involved in the photodynamic therapy of cancer. • Two new Bodipy derivatives bearing furanyl moiety were successfully prepared. • Imaging of intracellular singlet oxygen was obtained with bright BODIPY Dye (SOX1) • SOX1 proved to a satisfactory fluorescent probe to image singlet oxygen in HeLa Cells. [ABSTRACT FROM AUTHOR]