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By utilizing coordination-driven interaction between the carboxyl group of a conjugated polymer and metal ions, Cu2+ coordination-based conjugated polymer nanoparticles were developed for synergistic photodynamic and chemodynamic therapy for cancer.

By integrating the inhibitor of KIAA1363 enzyme, AX11890, into a red-absorbing dye, a tumor microenvironmental-responsive photosensitizer, NBS-L-AX, was developed for selective fluorescence imaging and activatable PDT therapy for breast cancers.

The regulation of photochemical properties of phototheranostics, especially the absorption, fluorescence, singlet oxygen (

Benzoyl peroxide (BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects on living organisms. Herein, we present a carbon dot (CD)-based fluorescent and colorimetric probe for visually, sensitively and selectively sensing BPO. The addition of BPO could quench the red fluorescence of CDs peaked at 622 and 677 nm, and decrease the absorbance at 613 nm, while increase the absorbance at 450 nm, resulting in a fluorescence turn-off and colorimetric spectral response. Moreover, the CDs had short response time of 10 min and high sensitivity towards BPO with a low limit of detection of 28 nmol/L. The applicability of the CDs in detecting BPO in wheat, noodle and starch samples was further demonstrated, and good recovery results were obtained.

Phototherapeutic agents with near-infrared (NIR) fluorescence, strong reactive oxygen species generation and photothermal conversion capabilities are highly desirable for use in cancer therapy. Herein, a water-soluble NIR croconaine dye (TCR) with a thiophene-croconaine rigid core and two symmetric alkyl chains was designed and synthesized. TCR exhibits intense NIR absorption and fluorescence that peaked at 780 and 815 nm, respectively, with a high molar extinction coefficient of 1.19 × 10

Nanosheet carriers loaded with drugs and phototherapeutics are used for effective cancer therapy, but the process remains challenging. Here, we prepared sulfur nanosheets (S-NSs) and then loaded tirapazamine (TPZ) and indocyanine green (ICG) with a loading efficiency of 6.3% and 94%, respectively. The obtained S-NSs-TPZ-ICG exhibits near-infrared (NIR) fluorescence, high

Photovoltaic molecules possess strong absorption in the near-infrared (NIR) region and are suitable for NIR laser-triggered phototherapy. Herein, the star molecule IEICO of organic photovoltaic materials, which has a narrow bandgap and large A-D-A conjugated structure, was prepared into water dispersive nanoparticles (NPs) through a simple self-assembly method. The obtained IEICO NPs showed a strong NIR absorption peak at 800 nm and a high

An estrogen receptor-targeted red-emissive photosensitizer was developed with enhanced PDT efficacy and imaging-guided ability in the therapy of breast cancers.

Photothermal therapy (PTT) has inherent advantages in the treatment of hypoxic tumors due to its optically controlled selectivity on tumor ablation and oxygen-independent nature. The subcellular organelle-targeting capability and photothermal conversion efficiency (PCE) at near-infrared (NIR) wavelength are the key parameters in the assessment of the photothermal agent (PTA). Here, we report that carbon dots (CDs) prepared by the hydrothermal treatment of coronene derivatives show a high PCE of 54.7% at 808 nm, which can be attributed to the narrow band gap and the presence of amounts of continuous energy bands on CDs. Moreover, the vibrations in the layered graphite structures of the CDs also increase the rate of nonradiative transition and thus enhance the PCE. Furthermore, the CDs also possess excellent photostability, biocompatibility, and cell penetration capability and could mainly accumulate in the lysosomes. These experiment results have proved that the CDs are suitable as an efficient NIR light-triggered PTA for efficient PTT against cancer.

For better investigating the complicated relationships between H2S and SO2, simultaneously detecting and visualizing them with good selectivity is crucial. However, most sensing mechanisms for H2S and SO2 probes are based on the addition reactions with the double bonds, which have no selectivity. In this work, by introducing an active triple bond into 4-dicyanovinyl-7-diethylamino-coumarin, we construct two unique sensors for not only distinguishing between H2S and SO2 but also sensing H2S and SO2 in a dual-ratiometric manner. Moreover, the modified sensor was successfully applied in living cells and zebrafish for discriminating H2S and SO2.

Carbon dots (CDs) have become popular nanomaterials in biomedical and agricultural fields. Herein we synthesized multifunctional CDs which showed anti-cancer and anti-fungal activities. The low cytotoxicity, stable fluorescence and high photothermal conversion efficiency enable the CDs with imaging-guided photothermal therapy. The CDs also exhibited intrinsic anti-fungal activity even at a low concentration, i.e., 40 mg·L−1 of CDs induced 20% mortality in cucumber downy mildew. Moreover, the large π-conjugated nanostructure and the richness of amino and hydroxyl groups make them a powerful delivery platform for flumorph (a fungicide) with a high loading efficiency of 47.18%. Meanwhile, the heat converted from the light can accelerate the release of flumorph from CDs, and thus efficiently kill fungus.

The blood-brain barrier (BBB) plays an irreplaceable role in protecting the central nervous system (CNS) from bloodborne pathogens. However, the BBB complicates the treatment of CNS diseases because it prevents almost all therapeutic drugs from getting into the CNS. With the growing understanding of the physiological characteristics of the BBB and the development of nanotechnology, nanomaterial-based drug delivery systems have become promising tools for delivering drugs across the BBB to the CNS. Herein, we systematically summarize the recent progress in organic-nanoparticle delivery systems for treating CNS diseases and evaluate their mechanisms in overcoming the BBB with the aim to provide a comprehensive understanding of the advantages, disadvantages, and challenges of organic nanoparticles in delivering drugs across the BBB. This review may inspire new research ideas and directions for applying nanotechnology to treat CNS diseases.

In recent years, carbon dots (CDs) have attracted great research interest in the field of nanochemosensors due to their fascinating optical properties. However, synthesis of CDs with novel recognition groups in a convenient method is still an area to be explored urgently. In this work, we reported a simple strategy to prepare fluorescent CDs with carbon-carbon double bonds (C═C) as the characteristic structure for phenylephrine (PHE) identification and detection. The itaconic acid and polyethylenimine (PEI) were selected as precursors to fabricate highly emissive CDs under the hydrothermal cross-linking and carbonization process. The fluorescence of designed CDs at 465 nm can be effectively quenched by bromine aqueous solution due to the electrophilic addition reaction with the double bonds. On the other hand, the presence of PHE can inhibit fluorescence quenching by bromine-consumption of a substitution reaction. Inspired by the novel findings, a convenient assay for PHE determination was established using the fluorescence of C═C bond functional CDs as an output signal and bromine as a bridge. The method demonstrated here provided a unique way to develop CD-based nanosensors.

Overexposure to hypochlorous acid (HOCl) can lead to cellular oxidative stress. In response to the stress, the body activates related factor that upregulates a potent antioxidant enzyme, NAD(P)H:quinone oxidoreductase 1 (NQO1). A method that can simultaneously detect HOCl and NQO1 can help to understand their interactions during homeostasis. However, the methods are still limited due to the complexity of the biological environment. In this work, we present for the first time a dual-ratiometric fluorescent probe (NH) that can distinguish between HOCl and NQO1. Probe NH had ratiometric fluorescence responses by changing from red (λ

Multimodal imaging-guided combinational phototherapies triggered by a single near-infrared (NIR) laser are highly desirable. However, their development is still a big challenge. Herein, we have developed an "acceptor-donor-acceptor'-donor-acceptor" structured organic phototheranostics (Y16-Pr) with strong light-harvesting ability in the NIR region. After being modified with polyethylene glycol (PEG), the obtained biocompatible nanoparticles (Y16-Pr-PEG NPs) could conduct NIR-II fluorescence imaging (FLI) and photoacoustic imaging (PAI) and perform photothermal therapy (PTT) and photodynamic therapy (PDT) simultaneously. Notably, Y16-Pr-PEG NPs showed an impressive photothermal conversion efficiency (PCE) of 82.4% under 808 nm laser irradiation. The irradiated NPs could also produce hydroxyl radicals (•OH) and singlet oxygen (

Sonodynamic therapy (SDT), as a novel non-invasive strategy for eliminating tumor, has the advantages of deeper tissue penetration, fewer side effects, and better patient compliance, compared with photodynamic therapy (PDT). In SDT, ultrasound was used to activate sonosensitizer to produce cytotoxic reactive oxygen species (ROS), induce the collapse of vacuoles in solution, and bring about irreversible damage to cancer cells. In recent years, much effort has been devoted to developing highly efficient sonosensitizers which can efficiently generate ROS. However, the traditional organic sonosensitizers, such as porphyrins, hypericin, and curcumins, suffer from complex synthesis, poor water solubility, and low tumor targeting efficacy which limit the benefits of SDT. In contrast, inorganic sonosensitizers show good in vivo stability, controllable physicochemical properties, ease of achieving multifunctionality, and high tumor targeting, which greatly expanded their application in SDT. In this review, we systematically summarize the nanomaterials which act as the carrier of molecular sonosensitizers, and directly produce ROS under ultrasound. Moreover, the prospects of inorganic nanomaterials for SDT application are also discussed.

A tetraphenylethylene-based aggregation-induced emission molecule (BT-5) bearing two positively charged imidazolium pendants and an alkyl chain (C10H20) was designed as a fluorescence turn-on probe...

A complex that was composed of β-cyclodextrin (β-CD) and a flavone derivative (compound 5) was designed as a colorimetric and fluorescence turn-on probe to discriminate thiophenol (PhSH) from bioth...

Spermine is an indicator of the meat freshness, and thus, developing efficient approaches with low cost for spermine detection is highly desirable. Here, we report a fluorometric probe for the sens...

An artificial photosynthetic assembly (APA) of a hollow-rod structure was successfully constructed by using synthetic building blocks to mimic the structure and function of natural photosynthetic bacteria. The APA was formed by the incorporation of carbon nanoparticles as light harvesters into an enzyme-like polymer, PEI-Co, containing cobalt complexes as redox catalytic centres. The APA features a bacteria-like shape of ca. 2–3 μm length rods and a hollow structure positioning photosynthetic components at the surface. The APA integrates key components, the light harvester, redox catalyst, and proton relay group, of photosynthetic systems in assemblies formed from a polymeric framework. The APA system in aqueous solution converts protons to H2 under visible light irradiation with obvious advantages. It exhibits a 50-fold improvement in hydrogen production activity and has a broader pH response of photocatalytic H2 production compared with a non-assembled system.

A novel ferrocene decorated vinyl pyridinium-substituted tetraphenylethylene (TPEPY-S-Fc) linked by a disulfide bond was designed as a GSH activatable photosensitizer by aggregation-induced emission for imaging-guided photodynamic therapy of cancer cells.

Correction for ‘Copper coordination-based conjugated polymer nanoparticles for synergistic photodynamic and chemodynamic therapy’ by Qiang Cheng et al., Chem. Commun., 2023, https://doi.org/10.1039/d3cc01107k.

For better investigating the complicated relationships between H

Surface ligand-removed and Cd-rich CdSe quantum dots (QDs) exhibited exceptional activity as photocatalyst for the conversion of CO2 to CO. A CO production rate up to 789 mmol g-1 h-1 was achieved in a triethylamine/dimethylformamide mixture under visible-light irradiation. Mechanistic studies revealed that improving the Cd/Se stoichiometric ratio and exposing more active surface Cd atoms significantly enhanced the activity of CdSe QDs for CO2 photoreduction.

A series of carbon nanoparticles (CNPs) with emission wavelength ranging from 483 to 525 nm were prepared by hydrothermal treatment of poly-3-thiopheneacetic acid (PTA) and NaOH. The emission wavelength and surface oxidation degree of CNPs were shown to be controllable by simply adjusting NaOH concentration. These CNPs presented obvious fluorescence spectral response toward copper ions (Cu2+) through static quenching caused synergistically by electron transfer and inner filter effect. The O- and S-containing groups on the surface of CNPs were demonstrated to be responsible for their outstanding sensing performance. Based on that, a CNPs-based ratiometric fluorescent probe for Cu2+ with a high fluorescence quenching rate constant of 1.4 × 105 L/mol and a short response time (10 s) was developed. Their practical applications in detecting Cu2+ in pond water and living cells were also demonstrated.

Image-guided photodynamic therapy (PDT) has received growing attention due to its non-invasiveness and precise controllability. However, the PDT efficiency of most photosensitizers are decreased in living system due to the aggregation-caused singlet oxygen (1 O2 ) generation decreasing. Herein, we present an Iridium (III) pyridylpyrrole complex (Ir-1) featuring of aggregation-induced emission (AIE) and 1 O2 generation characteristics for image-guided PDT of cancer. Ir-1 aqueous solution exhibits bright red phosphorescence peaked at 630 nm, large Stokes shift of 227 nm, and good 1 O2 generation ability. The 1 O2 generating rate of Ir-1 in EtOH/water mixture solution is 2.3 times higher than that of Rose Bengal. In vitro experimental results revealed that Ir-1 has better biocompatibility and higher phototoxicity compared with clinically used photosensitizers (Rose Bengal and Ce6), suggesting that Ir-1 can serve as a photosensitizer for image-guided PDT of cancer.

The number of cases of bacterial resistance to antibiotics has been exponentially rising over the last decade. This issue is getting worse as the research and development of new antibiotics is much slower than the speed of pathogenic bacteria acquiring resistance to antibiotic treatment. To fight against antibacterial resistance, new therapeutic strategies have to be sought as alternatives to currently administered antibiotics. Many new materials, for instance, metal organic frameworks possess desirable properties such as improved bacterial internalization, flexible structural control, high selectivity, and controlled drug release and therefore, are potentially good candidates for antibacterial therapy to overcome antibiotic resistance. This review describes the most recent development of the field of the antibacterial applications of metal organic frameworks, and their hybrids and derivatives, followed by an in-depth analysis of their advantages, disadvantages and design factors of these materials. Finally, we present our insights into the important aspects of the future development of metal organic frameworks for antibacterial applications.

Photothermal therapy (PTT) has received increasing attention due to its high selectivity, non-invasiveness, negligible drug resistance, oxygen independence, and minimal side effects. In PTT, photothermal agents (PTAs) absorb light energy and generate heat to kill cancer cells. Although various PTAs with strong near-infrared (NIR) light absorption and high photothermal conversion efficiency have been developed, their clinical uses in PTT still face with challenges. For example, maintaining a temperature of above 50°C for several minutes is needed to effectively ablate tumors, but this high temperature may destroy the surrounding normal tissues. Moreover, this rapid heating can induce an immune response that increases the cell tolerance to heat, which can weaken the therapeutic effects of PTT. In this review, we mainly focus on two approaches that have been developed to overcome the limitations of PTT, including inhibiting the expression of heat shock protein (Hsp) and regulating the metabolic processes of cells to develop low temperature PTT (LTPTT). We then discuss the existing challenges in clinical uses of LTPTT for treating tumors, and finally introduce future perspectives on the design of more effective therapeutic agents.

Nanocarrier-based drug delivery systems hold impressive promise for biomedical application because of their excellent water dispersibility, prolonged blood circulation time, increased drug accumulation in tumors, and potential in combination therapeutics. However, most nanocarriers suffer from low drug-loading efficiency, poor therapeutic effectiveness, potential systematic toxicity, and unstable metabolism. As an alternative, carrier-free nanodrugs, completely formulated with one or more drugs, have attracted increasing attention in cancer therapy due to their advantage of improved pharmacodynamics/pharmacokinetics, reduced toxicity, and high drug-loading. In recent years, carrier-free nanodrugs have contributed to progress in a variety of therapeutic modalities. In this review, different common strategies for carrier-free nanodrugs preparation are first summarized, mainly including nanoprecipitation, template-assisted nanoprecipitation, thin-film hydration, spray-drying technique, supercritical fluid (SCF) technique, and wet media milling. Then we describe the recently reported carrier-free nanodrugs for cancer chemo-monotherapy or combination therapy. The advantages of anti-cancer drugs combined with other chemotherapeutic, photosensitizers, photothermal, immunotherapeutic or gene drugs have been demonstrated. Finally, a future perspective is introduced to highlight the existing challenges and possible solutions toward clinical application of currently developed carrier-free nanodrugs, which may be instructive to the design of effective carrier-free regimens in the future.

Two-photon excitation (TPE) photodynamic therapy (PDT) has attracted great interest due to its distinctive properties, e.g., good penetration ability of biological tissues and less damage to healthy tissues. However, the conventional photosensitizers (PSs) for PDT have poor subcellular location capability and low two-photon absorption (TPA) cross section in the phototherapeutic window. Herein, we report a fascinating multi-functional TPE PS, polythiophene nanoparticles (PT NPs), for simultaneous lysosome-targetable fluorescence imaging and PDT. PT NPs show bright yellow fluorescence, good water solubility as well as excellent photo- and pH-stability. Moreover, PT NPs exhibit high singlet oxygen generation quantum yield (∼42%) and large TPA cross section (∼3420 GM). A fluorescence imaging penetration depth of 1800 μm could be reached in the tissue phantom under the TPE mode. Due to these outstanding merits and their unique clathrin- and caveola-independent intracellular uptake pathway, PT NPs have great potential for application in TPE fluorescence imaging and photodynamic therapy.

Carbon nanoparticles (CNPs) with strong blue emission are synthesized using a microwave-assisted hydrothermal method. The fluorescence of the CNPs can be completely quenched by Hg2+ through an effective electron or energy transfer process due to the synergetic strong electrostatic interaction and metal–ligand coordination. Based on this, a system containing Hg2+-quenched CNPs (CNP-Hg2+) is designed to be a sensitive and selective turn-on fluorescent probe towards cysteine (a type of mercapto biomolecule) with a detection limit of 15 nM. The fluorescence of CNP-Hg2+ aqueous solution can be repeatedly turned on and off for over 10 times by alternative addition of cysteine and Hg2+, respectively. After 10 cycles, the fluorescence intensity could be recovered to as high as 85% of the original value of CNPs. Remarkably, the sensing process is able to be observed by the naked eye under UV irradiation. Furthermore, the sensing is specific to biothiols and the sensor is able to work in living cells.

Photosensitizers (PSs) with aggregation-induced emission (AIE) feature show promising applications in fluorescence imaging-guided photodynamic therapy (PDT) in virtue of their enhanced fluorescence and phototoxicity in aggregate state. Seeking the ideal AIE luminogens (AIEgens) with good capability of generating reactive oxygen species is still urgent. Here we rationally synthesized an acceptor-donor-acceptor (A-D-A) structured AIEgen (BTZPP) and then prepared it into nanoparticles (NPs) through a simple re-precipitation procedure. The obtained BTZPP NPs show a deep-red emission peaked at 635 nm, a large Stokes shift of 195 nm, and a high 1O2 generation quantum yield of 72.3%. Moreover, these NPs can selectively target lysosomes in live cells and image mouse tumor with a high contrast and long-term tracking (up to 14 days) capability. The high-efficiency imaging-guided PDT against cancer cells and tumors is successfully demonstrated in vitro and in vivo.

Doping is an effective approach to regulate the physicochemical properties of carbon dots (CDs) and has received increasing attention in recent years. After CDs are doped with heteroatoms, their electronic structure, nanostructure, and chemical composition will be changed due to the overlapping atomic orbitals of the heteroatoms and carbon atoms, as well as the push/pull electron effect of heteroatoms. As compared with the non-metallic atoms, metal ions have more electron and unoccupied orbitals, and larger atomic radius, doping CDs with metal ions may induce noticeable alterations of the optical, electronic, and magnetic properties by changing the electron density distribution and energy gap of the CDs. In this review, we summarize the synthesis methods of metal ions-doped CDs (M−CDs), discuss the novel physicochemical properties originating from the doping of metal ions, and provide examples of applications in sensing, imaging, phototherapy, optoelectronics, and catalysis. Furthermore, we describe challenges in preparing M−CDs and provide an outlook for their future development.