Phosphorene, also known as single- or few-layer black phosphorus (FLBP), is a new member of the two-dimensional (2D) material family and has attracted significant attention in recent years for applications in optoelectronics, energy storage and biomedicine due to its unique physicochemical properties and excellent biocompatibility. FLBP is regarded as a potential biological imaging agent for cancer diagnosis due to its intrinsic fluorescence (FL) and photoacoustic (PA) properties and negligible cytotoxicity. FLBP-based photothermal and photodynamic therapies have emerged with excellent anti-tumour therapeutic efficacies due to their unique physical properties, such as near-infrared (NIR) optical absorbance, large extinction coefficients, biodegradability and reactive oxygen species (ROS) or heat generation upon light irradiation. Furthermore, FLBP is a promising drug delivery platform because of its high drug-loading capacity due to its puckered layer structure with an ultralarge surface area, and FLBP is size-controllable with facile surface chemical modification. Because of the marked advantages of FLBP nanomaterials in biomedical applications, an overview of the latest progress and paradigms of FLBP-based nanoplatforms for multidisciplinary biomedical applications is presented in this tutorial review.

Abnormal microenvironments (viscosity, polarity, pH, etc.) have been verified to be closely associated with numerous pathophysiological processes such as inflammation, neurodegenerative diseases, and cancer.

Immunogenic cell death (ICD) is a unique mode of cell death that could trigger tumour-specific immune response. Metal-based drugs which have emerged as promising agents within the lexicon of possible ICD inducers will be the topic of this review.

Activatable (turn‐on) probes that permit the rapid, sensitive, selective, and accurate identification of cancer‐associated biomarkers can help drive advances in cancer research. Herein, a NAD(P)H:quinone oxidoreductase‐1 (NQO1)‐specific chemiluminescent probe 1 is reported that allows the differentiation between cancer subtypes. Probe 1 incorporates an NQO1‐specific trimethyl‐locked quinone trigger moiety covalently tethered to a phenoxy‐dioxetane moiety through a para‐aminobenzyl alcohol linker. Bio‐reduction of the quinone to the corresponding hydroquinone results in a chemiluminescent signal. As inferred from a combination of in vitro cell culture analyses and in vivo mice studies, the probe is safe, cell permeable, and capable of producing a “turn‐on” luminescence response in an NQO1‐positive A549 lung cancer model. On this basis, probe 1 can be used to identify cancerous cells and tissues characterized by elevated NQO1 levels.

A high brightness red fluorescent probe (S-BODIPY) has been developed for the sensitive and specific imaging of HClO/ClO − in vitro and in vivo. This probe exhibits some distinctive features such as excellent resistance to photobleaching, a high fluorescence brightness, high selectivity, as well as a good biocompatibility. Upon oxidation of the thioether group into sulfoxide, the probe showed a noticeable ratiometric fluorescence response toward ClO − with fast response (within 30 s) and a low detection limit (59 nM). The probe demonstrated the successful imaging of exogenous and endogenous HClO/ClO − in living HeLa cells, zebrafish, and mice with high signal-to-noise ratios. S-BODIPY allows for the real-time monitoring the level of ClO − in living cells by ratiometric fluorescence imaging, opening up exciting prospects to develop red and even near-infrared BODIPYs with high brightness and good photostability for in vivo imaging.

Both chronic and acute neurodegenerative diseases have been associated with high morbidity and mortality, along with the death of neurons in different areas of the brain, and there are few or no effective curative therapy options for treatment of patients. [3,4] These disorders are a major cause of concern for the health and quality of life in the aging society, since age is the greatest risk factor for neurodegenerative disease. [5] The World Health Organization has predicted that in next 20 years neurodegenerative disease will become the second most common cause of mortality after cardiovascular disease. [6] Neurodegenerative processes begin long before their clinical symptoms are evident, and evolve for years slowly and irreversibly. Hence, there is an urgent need to diagnose neurodegenerative disease as early as possible and to distinguish between different neurodegenerative disorders with shared and unique symptoms to facilitate decision making regarding choice of treatment. Timely diagnosis is important for the adoption of therapeutic modalities in clinical trials prior to moderate dementia exhibition, to appraise and apply antidotes to maximally preserve the cognitive functions or to slow down the course of these disorders. The ability to analyze and identify risk factors for cognitive deficit would represent an extraordinary advancement in the field of dementia. [5] The main modern diagnostic technologies for the early examination of neurodegenerative disease pathology, neuroimaging techniques, include radioligandsbased positron emission tomography (PET), 3D single-photon emission-computed tomography (SPECT), and structural magnetic resonance imaging (MRI). Although PET and SPECT are the most used imaging techniques for neurodegenerative diseases, their application is limited by high cost, involvement of hazardous radiolabeled compounds, need for sophisticated instruments, and application of complex data acquisition and analysis protocols. The MRI technique has relatively low spatial resolution as well as intrinsically poor sensitivity to distinguish morphological differences between disease biomarkers and the surrounding tissue. Recently, fluorescence diagnosis technology has become an attractive and potential alternative to diagnose and probe the progression of neurodegenerative diseases, because of being rapid, noninvasive, sensitive, simple, real-time, low-cost, and high-resolution in nature. [7] There are several uses for Neurodegenerative diseases are debilitating disorders that feature progressive and selective loss of function or structure of anatomically or physiologically associated neuronal systems. Both chronic and acute neurodegenerative diseases are associated with high morbidity and mortality along with the death of neurons in different areas of the brain; moreover, there are few or no effective curative therapy options for treating these disorders. There is an urgent need to diagnose neurodegenerative disease as early as possible, and to distinguish between different disorders with overlap...

Characteristics of CSCs targeted for developing therapeutic and bio-imaging agents.

Reported here is a molecular construct (K1) designed to overcome hurdles associated with delivering active drugs to heterogeneous tumor environments. Construct K1 relies on two cancer environment triggers (GSH and H 2 O 2 ) to induce prodrug activation. It releases an active drug form (SN-38) under conditions of both oxidative and reductive stress in vitro. Specific uptake of K1 in COX-2 positive aggressive colon cancer cells (SW620 and LoVo) was seen, along with enhanced anticancer activity compared with the control agent SN-38. These findings are attributed to environmentally triggered drug release, as well as simultaneous scavenging of species giving rise to intracellular redox stress. K1 serves to downregulate various cancer survival signaling pathways (AKT, p38, IL-6, VEGF, and TNF-α) and upregulate an anti-inflammatory response (IL-10). Compared with SN-38 and DMSO as controls, K1 also displayed an improved in vivo therapeutic efficacy in a xenograft tumor regrowth model with no noticeable systematic toxicity at the administrated dose. We believe that the strategy described here presents an attractive approach to addressing solid tumors characterized by intratumoral heterogeneity.