One Stone, Two Birds: High-Brightness Aggregation-Induced Emission Photosensitizers for Super-Resolution Imaging and Photodynamic Therapy.

Most aggregation-induced emission (AIE) luminogens exhibit high brightness, excellent photostability, and good biocompatibility, but these AIE-active agents, which kill two birds with one stone to result in applications in both stimulated emission depletion (STED) super-resolution imaging and photodynamic therapy (PDT), have not been reported yet but are urgently needed. To meet the requirements of STED nanoscopy and PDT, D-A-π-A-D type DTPABT-HP is designed by tuning conjugated π spacers. It exhibits red-shifted emission, high PLQY of 32.04%, and impressive 1O2 generation (9.24 fold compared to RB) in nanoparticles (NPs). Then, DTPABT-HP NPs are applied in cell imaging via STED nanoscopy, especially visualizing the dynamic changes of lysosomes in the PDT process at ultrahigh resolution. After that, in vivo PDT was also conducted by DTPABT-HP NPs, resulting in significantly inhibited tumor growth, with an inhibition rate of 86%. The work here is beneficial to the design of multifunctional agents and the deep understanding of their phototheranostic mechanism in biological research.

End Group Engineering for Constructing A-D-A Fused-Ring Photosensitizers with Balanced Phototheranostics Performance.

Phototheranostics continues to flourish in cancer treatment. Due to the competitive relationships between these photophysical processes of fluorescence emission, photothermal conversion, and photodynamic action, it is critical to balance them through subtle photosensitizer designs. Herein, it is provided a useful guideline for constructing A-D-A photosensitizers with superior phototheranostics performance. Various cyanoacetate group-modified end groups containing ester side chains of different length are designed to construct a series of A-D-A photosensitizers (F8CA1 ∼ F8CA4) to study the structure-property relationships. It is surprising to find that the photophysical properties of A-D-A photosensitizers can be precisely regulated by these tiny structural changes. The results reveal that the increase in the steric hindrance of ester side chains has positive impacts on their photothermal conversion capabilities, but adverse impacts on the fluorescence emission and photodynamic activities. Notably, these tiny structural changes lead to their different aggregation behavior. The molecule mechanisms are detailedly explained by theoretical calculations. Finally, F8CA2 nanoparticles with more balanced photophysical properties perform well in fluorescence imaging-guided photothermal and type I&II photodynamic synergistic cancer therapy, even under hypoxic conditions. Therefore, this work provides a novel practicable construction strategy for desired A-D-A photosensitizers.

Organic Photothermal Materials Obtained Using Thermally Activated Delayed Fluorescence Design Principles.

Organic small molecules with high photothermal conversion efficiencies that absorb near-infrared light are desirable for photothermal therapy due to their improved biocompatibility compared to inorganic materials and their ability to absorb light in the biological transparency window (650-1350 nm). Here we report three donor-acceptor organic materials DM-ANDI, O-ANDI, and S-ANDI that show high photothermal conversion efficiencies of 46-68 % with near-infrared absorption. The design of these molecules is based on the rational modification of a thermally activated delayed fluorescence material to favour a low photoluminescence quantum yield by reducing HOMO-LUMO overlap. Encapsulating these materials into either neat nanoparticles or aggregated organic dots modulates their photothermal conversion efficiencies, and also facilitates dispersion in water.

As Aggregation-Induced Emission Meets with Noncovalent Conformational Locks: Subtly Regulating NIR-II Molecules for Multimodal Imaging-Navigated Synergistic Therapies.

Phototheranostics is growing into a sparking frontier in disease treatment. Developing single molecular species synchronously featured by powerful absorption capacity, superior second near-infrared (NIR-II) fluorescence and prominent photothermal conversion ability is highly desirable for phototheranostics, yet remains formidably challenging. In this work, we propose a molecular design philosophy that the integration of noncovalent conformational locks (NoCLs) with aggregation-induced emission (AIE) in a single formulation is able to boost multiple photophysical properties for efficient phototheranostics. The introduction of NoCLs skeleton with conformation-locking feature in the center of molecular architecture indeed elevates the structural planarity and rigidity, which simultaneously promotes the absorption capacity and bathochromic-shifts the emission wavelength centered in NIR-II region. Meanwhile, the AIE tendency mainly originated from flexibly propeller-like geometry at the ends of molecular architecture eventually endows the molecule with satisfactory emission intensity and photothermal conversion in aggregates. Consequently, by utilizing the optimized molecule, unprecedented performance on NIR-II fluorescence-photoacoustic-photothermal trimodal imaging-guided photothermal-chemo synergistic therapy is demonstrated by the precise tumor diagnosis and complete tumor ablation.

An All-Rounder for NIR-II Phototheranostics: Well-Tailored 1064 nm-Excitable Molecule for Photothermal Combating of Orthotopic Breast Cancer.

The second near-infrared (NIR-II, 1000-1700 nm) light-activated organic photothermal agent that synchronously enables satisfying NIR-II fluorescence imaging is highly warranted yet rather challenging on the basis of the overwhelming nonradiative decay. Herein, such an agent, namely TPABT-TD, was tactfully designed and constructed via employing benzo[c]thiophene moiety as bulky electron donor/π-bridge and tailoring the peripheral molecular rotors. Benefitting from its high electron donor-acceptor strength and finely modulated intramolecular motion, TPABT-TD simultaneously exhibits ultralong absorption in NIR-II region, intense fluorescence emission in the NIR-IIa (1300-1500 nm) region as nanoaggregates, and high photothermal conversion upon 1064 nm laser irradiation. Those intrinsic advantages endow TPABT-TD nanoparticles with prominent fluorescence/photoacoustic/photothermal trimodal imaging-guided NIR-II photothermal therapy against orthotopic 4T1 breast tumor with negligible adverse effect.

Thiophene π-Bridge Manipulation of NIR-II AIEgens for Multimodal Tumor Phototheranostics.

The fabrication of a multimodal phototheranostic platform on the basis of single-component theranostic agent to afford both imaging and therapy simultaneously, is attractive yet full of challenges. The emergence of aggregation-induced emission luminogens (AIEgens), particularly those emit fluorescence in the second near-infrared window (NIR-II), provides a powerful tool for cancer treatment by virtue of adjustable pathway for radiative/non-radiative energy consumption, deeper penetration depth and aggregation-enhanced theranostic performance. Although bulky thiophene π-bridges such as ortho-alkylated thiophene, 3,4-ethoxylene dioxythiophene and benzo[c]thiophene are commonly adopted to construct NIR-II AIEgens, the subtle differentiation on their theranostic behaviours has yet to be comprehensively investigated. In this work, systematical investigations discovered that AIEgen BT-NS bearing benzo[c]thiophene possesses acceptable NIR-II fluorescence emission intensity, efficient reactive oxygen species generation, and high photothermal conversion efficiency. Eventually, by using of BT-NS nanoparticles, unprecedented performance on NIR-II fluorescence/photoacoustic/photothermal imaging-guided synergistic photodynamic/photothermal elimination of tumors was demonstrated. This study thus offers useful insights into developing versatile phototheranostic systems for clinical trials.

Deciphering Oxygen-Independent Augmented Photodynamic Oncotherapy by Facilitating the Separation of Electron-Hole Pairs.

Developing Type-I photosensitizers provides an attractive approach to solve the dilemma of inadequate efficacy of photodynamic therapy (PDT) caused by the inherent oxygen consumption of traditional Type-II PDT and anoxic tumor microenvironment. The challenge for the exploration of Type-I PSs is to facilitate the electron transfer ability of photosensitization molecules for transforming oxygen or H2O to reactive oxygen species (ROS). Herein, we propose an electronic acceptor-triggered photoinduced electron transfer (a-PET) strategy promoting the separation of electron-hole pairs by marriage of two organic semiconducting molecules of a non-fullerene scaffold-based photosensitizer and a perylene diimide that significantly boost the Type-I PDT pathway to produce plentiful ROS, especially, inducing 3.5-fold and 2.5-fold amplification of hydroxyl (OH⋅) and superoxide (O2 -⋅) generation. Systematic mechanism exploration reveals that intermolecular electron transfer and intramolecular charge separation after photoirradiation generate a competent production of radical ion pairs that promote the Type-I PDT process by theoretical calculation and ultrafast femtosecond transient absorption (fs-TA) spectroscopy. By complementary tumor diagnosis with photoacoustic imaging and second near-infrared fluorescence imaging, this as-prepared nanoplatform exhibits fabulous photocytotoxicity in harsh hypoxic conditions and terrific cancer revoked abilities in living mice. We envision that this work will broaden the insight into high-efficiency Type-I PDT for cancer phototheranostics.

Fused Azulenyl Squaraine Derivatives Improve Phototheranostics in the Second Near-Infrared Window by Concentrating Excited State Energy on Non-Radiative Decay Pathways.

The second near-infrared (NIR-II) theranostics offer new opportunities for precise disease phototheranostic due to the enhanced tissue penetration and higher maximum permissible exposure of NIR-II light. However, traditional regimens lacking effective NIR-II absorption and uncontrollable excited-state energy decay pathways often result in insufficient theranostic outcomes. Herein a phototheranostic nano-agent (PS-1 NPs) based on azulenyl squaraine derivatives with a strong NIR-II absorption band centered at 1092 nm is reported, allowing almost all absorbed excitation energy to dissipate through non-radiative decay pathways, leading to high photothermal conversion efficiency (90.98 %) and strong photoacoustic response. Both in vitro and in vivo photoacoustic/photothermal therapy results demonstrate enhanced deep tissue cancer theranostic performance of PS-1 NPs. Even in the 5 mm deep-seated tumor model, PS-1 NPs demonstrated a satisfactory anti-tumor effect in photoacoustic imaging-guided photothermal therapy. Moreover, for the human extracted tooth root canal infection model, the synergistic outcomes of the photothermal effect of PS-1 NPs and 0.5 % NaClO solution resulted in therapeutic efficacy comparable to the clinical gold standard irrigation agent 5.25 % NaClO, opening up possibilities for the expansion of NIR-II theranostic agents in oral medicine.

NIR-II AIEgens for Infectious Diseases Phototheranostics.

Pathogenic infectious diseases have persistently posed significant threats to public health. Phototheranostics, which combines the functions of diagnostic imaging and therapy, presents an extremely promising solution to block the spread of pathogens as well as the outbreak of epidemics owing to its merits of a wide-spectrum of activity, high controllability, non-invasiveness, and difficult to acquire resistance. Among multifarious phototheranostic agents, second near-infrared (NIR-II, 1000-1700 nm) aggregation-induced emission luminogens (AIEgens) are notable by virtue of their deep penetration depth, excellent biocompatibility, balanced radiative and nonradiative decay and aggregation-enhanced theranostic performance, making them an ideal option for combating pathogens. This minireview provides a systematical summary of the latest advancements in NIR-II AIEgens with emphasis on the molecular design and nanoplatform formulation to fulfill high-efficiency in treating bacterial and viral pathogens, classified by disease models. Then, the current challenges, potential opportunities, and future research directions are presented to facilitate the further progress of this emerging field.

Molecular Oligomerization and Donor Engineering Strategies for Achieving Superior NIR-II Fluorescence Imaging and Thermotherapy under 1064 nm Laser Irradiation.

An enormous challenge still exists for designing molecules with the second near-infrared (NIR-II, 1000-1700 nm) window absorption, NIR-II fluorescence emission, and batch-to-batch reproducibility, which is the premise for high-performance NIR-II phototheranostics. Although organic small molecules and polymers have been largely explored for phototheranostics, it is difficult to satisfy the above three elements simultaneously. In this work, molecular oligomerization (the general structure is S-D-A-D'-A-D-S) and donor engineering (changing the donor linker D') strategies are applied to design phototheranostic agents. Such strategies are proved to be efficient in adjusting molecular configuration and energy level, affecting the optical and thermal properties. Three oligomers (O-T, O-DT, and O-Q) are further prepared into water-soluble nanoparticles (NPs). Particularly, the O-T NPs exhibit a higher molar extinction coefficient at 1064 nm (≈4.3-fold of O-DT NPs and ≈4.8-fold of O-Q NPs). Furthermore, the O-T NPs show the highest NIR-II fluorescence brightness and heating capacity (PCE = 73%) among the three NPs under 1064 nm laser irradiation and served as agents for NIR-II imaging guided in vivo photothermal therapy. Overall, by using molecular oligomerization and donor engineering strategies, a powerful example of constructing high-performance NIR-II phototheranostics for clinical translation is given.

Molecular Engineering of NIR-II/IIb Emitting AIEgen for Multimodal Imaging-Guided Photo-Immunotherapy.

In view of the great challenges related to the complexity and heterogeneity of tumors, efficient combination therapy is an ideal strategy for eliminating primary tumors and inhibiting distant tumors. A novel aggregation-induced emission (AIE) phototherapeutic agent called T-TBBTD is developed, which features a donor-acceptor-donor (D-A-D) structure, enhanced twisted molecule conformation, and prolonged second near-infrared window (NIR-II) emission. The multimodal imaging function of the molecule has significance for its treatment time window and excellent photothermal/photodynamic performance for multimode therapy. The precise molecular structure and versatility provide prospects for molecular therapy for anti-tumor applications. Fluorescence imaging in the NIR-II window offers advantages with enhanced spatial resolution, temporal resolution, and penetration depth. The prepared AIE@R837 NPs also have controllable performance for antitumor photo-immunotherapy. Following local photo-irradiation, AIE@R837 NPs generate abundant heat, and 1 O2 directly kills tumor cells, induces immunogenic cell death (ICD) as a photo-therapeutic effect, and releases R837, which enhances the synergistic effect of antigen presentation and contributes to the long-lasting protective antitumor immunity. A bilateral 4T1 tumor model revealed that this photo-immunotherapy can eliminate primary tumors. More importantly, it has a significant inhibitory effect on distant tumor growth. Therefore, this method can provide a new strategy for tumor therapy.

Smart Phototheranostics based on Carbon Nanohorns for Precise Imaging-Guided Post-PDT toward Residual Tumor Cells after Initial Phototherapy.

As promising photonic material, phototheranostics can be activated in the laser irradiation range of tumor with sensitivity and spatiotemporal precision. However, it is difficult to completely eradicate solid tumors due to their irregularity and limited laser irradiation area. Herein, multi-stimulus responsive HA-Ce6@SWNHs were constructed with single-walled carbon nanohorns (SWNHs) and chlorine e6 (Ce6) modified hyaluronic acid (HA) via non-covalent binding. This SWNHs-based phototheranostics not only exhibited water dispersion but also could target tumor and be activated by near-infrared light for photodynamic therapy (PDT) and photothermal therapy (PTT). Additionally, HA-Ce6@SWNHs could be degraded by hyaluronidase in residual tumor cells, causing HA-Ce6 to fall off the SWNHs surfaces to restore autofluorescence, thus precisely guiding the programmed photodynamic treatments for residual tumor cells after the initial phototherapy. Thus, this work provides a rationally designed multiple-stimulus-response strategy to develop smart SWNHs-based phototheranostics for precise PDT/PTT and post-treatment imaging-guided PDT of residual tumor cells.

Reviewing the evolutive ACQ-to-AIE transformation of photosensitizers for phototheranostics.

Photodynamic therapy (PDT) represents an emerging noninvasive treatment technique for cancers and various nonmalignant diseases, including infections. During the process of PDT, the physical and chemical properties of photosensitizers (PSs) critically determine the effectiveness of PDT. Traditional PSs have made great progress in clinical applications. One of the challenges is that traditional PSs suffer from aggregation-caused quenching (ACQ) due to their discotic structures. Recently, aggregation-induced emission PSs (AIE-PSs) with a twisted propeller-shaped conformation have been widely concerned because of high reactive oxygen species (ROS) generation efficiency, strong fluorescence efficiency, and resistance to photobleaching. However, AIE-PSs also have some disadvantages, such as short absorption wavelengths and insufficient molar absorption coefficient. When the advantages and disadvantages of AIE-PSs and ACQ-PSs are complementary, combining ACQ-PSs and AIE-PSs is a "win-to-win" strategy. As far as we know, the conversion of traditional representative ACQ-PSs to AIE-PSs for phototheranostics has not been reviewed. In the review, we summarize the recent progress on the ACQ-to-AIE transformation of PSs and the strategies to achieve desirable theranostic applications. The review would be helpful to design more efficient ACQ-AIE-PSs in the future and to accelerate the development and clinical application of PDT.

"Dual-Key-and-Lock" NIR-II NSCyanines Enable High-Contrast Activatable Phototheranostics in Extrahepatic Diseases.

Conventional cyanine dyes with a symmetric structure are "always-on", which can easily accumulate in the liver and display high liver background fluorescence, inevitably interfering the accurate diagnosis and therapy in extrahepatic diseases. We herein report a platform of NIR-II non-symmetric cyanine (NSCyanine) dyes by harnessing a non-symmetric strategy, which are extremely sensitive to pH/viscosity and can be activated via a "dual-key-and-lock" strategy. These NSCyanine dyes with a low pKa (<4.0) only show weak fluorescence at lysosome pH (key1), however, the fluorescence can be completely switched on and significantly enhanced by intracellular viscosity (key2) in disease tissues, exhibiting high target-to-liver ratios up to 19.5/1. Notably, high-contrast phototheranostics in extrahepatic diseases are achieved, including intestinal metastasis-imaging, acute gastritis-imaging, bacteria infected wound healing, and tumor ablation via targeted combined photothermal therapy and chemotherapy.

Near-Infrared II Plasmonic Phototheranostics with Glutathione Depletion for Multimodal Imaging-Guided Hypoxia-Tolerant Chemodynamic-Photocatalytic-Photothermal Cancer Therapy Triggered by a Single Laser.

Tumor microenvironment (TME)-activatable phototheranostics is highly desirable in cancer management but still remains challenging for clinical applications owing to the lack of multifunctional theranostic agents and the limited tissue penetration depth. Reported here is an "all-in-one" phototheranostic platform based on near-infrared II (NIR-II) dual-plasmonic Au@Cu2-x Se core-shell nanocrystals (dpGCS NCs) for combined photoacoustic (PA)/photothermal (PT) imaging-guided chemodynamic therapy (CDT)/photocatalytic therapy (PCT)/photothermal therapy (PTT) all triggered by a single NIR-II laser. The dpGCS NCs feature excellent NIR-II plasmonic and PT properties, which guarantee their capabilities of NIR-II PA and PT imaging for real-time visual observation of tumor size and location during cancer treatment. Additionally, the TME-activated in situ •OH production via dpGCS NC-catalyzed Fenton-like reaction is further enhanced by the NIR-II irradiation, while photoexcited plasmonic hole-induced formation of extra •OH is also evidenced for PCT. Both in vitro and in vivo experiments confirm remarkable therapeutic efficacy of the present phototheranostic platform under NIR-II laser through the CDT/PCT/PTT trimodal combination therapy, achieving complete inhibition of tumor growth in tumor-bearing mice after administration of dpGCS NCs plus a single NIR-II laser irradiation. This work provides a distinctive paradigm for the development of NIR-II phototheranostic platforms for imaging-guided cancer therapy using a single laser.

A Facile Structural Isomerization-Induced 3D Spatial D-A Interlocked Network for Achieving NIR-II Phototheranostic Agents.

The performances of second near-infrared (NIR-II) organic phototheranostic agents (OPTAs) depend on both molecular structure and molecular packing when used as nanoparticles (NPs). Herein, we proposed a facile structural isomerization-induced 3D spatial donor (D)-acceptor (A) interlocked network for achieving NIR-II OPTAs. Two isomers, 4MNVDPP and 6MNVDPP were synthesized and formulated into NPs. 6MNVDPP, which has a larger electrostatic potential difference, exhibits a compact 3D spatial D-A interlocked network in the crystal form, while 4MNVDPP forms 2D D-D type J-aggregates. Thus, 6MNVDPP NPs show red-shifted NIR absorption and larger molar extinction coefficient than 4MNVDPP NPs. Thanks to the typical NIR-II emission, superior photothermal-stability, high photothermal conversion efficiency (89 %) and reactive oxygen species production capacity, 6MNVDPP NPs exhibit outstanding NIR-II tiny capillary vasculature/tumor imaging ability and synergistic photothermal/photodynamic anti-cancer effect in vivo.

Add the Finishing Touch: Molecular Engineering of Conjugated Small Molecule for High-Performance AIE Luminogen in Multimodal Phototheranostics.

Phototheranostics based on luminogens with aggregation-induced emission (AIE) characteristics is captivating increasing research interest nowadays. However, AIE luminogens are inherently featured by inferior absorption coefficients (ε) resulting from the distorted molecular geometry. Besides, molecular innovation of long-wavelength light-excitable AIE luminogens with highly efficient phototheranostic outputs is an appealing yet significantly challenging task. Herein, on the basis of a fused-ring electron acceptor-donator-acceptor (A-D-A) type molecule (IDT) with aggregation-caused quenching (ACQ) properties, molecular engineering smoothly proceeds and successfully yields a novel AIE luminogen (IDT-TPE) via simply modifying tetraphenylethene (TPE) moieties on the sides of IDT backbone. The AIE tendency endows IDT-TPE nanoparticles with enhanced fluorescence brightness and far superior fluorescence imaging performance to IDT nanoparticles for mice tumors. Moreover, IDT-TPE nanoparticles exhibit near-infrared light-excitable features with a high ε of 8.9 × 104 m-1 cm-1 , which is roughly an order of magnitude higher than that of most previously reported AIE luminogens. Combining with their reactive oxygen species generation capability and extremely high photothermal conversion efficiency (59.7%), IDT-TPE nanoparticles actualize unprecedented performance in multimodal phototheranostics. This study thus brings useful insights into the development of versatile phototheranostic materials with great potential for practical cancer theranostics.

Rational Design of All-Organic Nanoplatform for Highly Efficient MR/NIR-II Imaging-Guided Cancer Phototheranostics.

Organic theranostic nanomedicine has precision multimodel imaging capability and concurrent therapeutics under noninvasive imaging guidance. However, the rational design of desirable multifunctional organic theranostics for cancer remains challenging. Rational engineering of organic semiconducting nanomaterials has revealed great potential for cancer theranostics largely owing to their intrinsic diversified biophotonics, easy fabrication of multimodel imaging platform, and desirable biocompatibility. Herein, a novel all-organic nanotheranostic platform (TPATQ-PNP NPs) is developed by exploiting the self-assembly of a semiconducting small molecule (TPATQ) and a new synthetic high-density nitroxide radical-based amphiphilic polymer (PNP). The nitroxide radicals act as metal-free magnetic resonance imaging agent through shortened longitudinal relaxation times, and the semiconducting molecules enable ultralow background second near-infrared (NIR-II, 1000-1700 nm) fluorescence imaging. The as-prepared TPATQ-PNP NPs can light up whole blood vessels of mice and show precision tumor-locating ability with synergistic (MR/NIR-II) imaging modalities. The semiconducting molecules also undergo highly effective photothermal conversion in the NIR region for cancer photothermal therapy guided by complementary tumor diagnosis. The designed multifunctional organic semiconducting self-assembly provides new insights into the development of a new platform for cancer theranostics.

Donor/π-Bridge Manipulation for Constructing a Stable NIR-II Aggregation-Induced Emission Luminogen with Balanced Phototheranostic Performance*.

Owing to their versatile functionality and tunable energy dissipation, aggregation-induced emission luminogens (AIEgens) have emerged as a potential platform for multimodal theranostics. Nevertheless, the construction of AIE-active phototheranostic agents in the second near-infrared window (NIR-II, 1000-1700 nm), which allows superior resolution and minimized photodamage, is still a formidable challenge. Herein, benzo[c]thiophene serves as an electron-rich and bulky donor (D)/π-bridge, which can enlarge the conjugation length and distort the backbone of an AIEgen. By precise D/π-bridge engineering, highly stable NIR-II AIEgen DPBTA-DPTQ nanoparticles are obtained with acceptable NIR-II fluorescence quantum yield and excellent photothermal conversion efficiency. In addition, the spatial conformation of DPBTA-DPTQ is determined for the first time by X-ray single crystal diffraction and theoretical simulations. DPBTA-DPTQ NPs have good biocompatibility and show efficient photothermal therapeutic effects in in vitro tests. Furthermore, DPBTA-DPTQ NPs were used in fluorescence-photoacoustic-photothermal trimodal imaging-guided photothermal eradication of tumors in HepG2 and B16-F10 tumor-xenografted mice.

Upconverting Carbon Nanodots from Ethylenediaminetetraacetic Acid (EDTA) as Near-Infrared Activated Phototheranostic Agents.

This work describes the synthesis of nitrogen-doped carbon nanodots (CNDs) synthesized from ethylenediaminetetraacetic acid (EDTA) as a precursor and their application as luminescent agents with a dual-mode theranostic role as near-infrared (NIR) triggered imaging and photodynamic therapy agents. Interestingly, these fluorescent CNDs are more rapidly and selectively internalized by tumor cells and exhibit very limited cytotoxicity until remotely activated with a NIR illumination source. These CNDs are excellent candidates for phototheranostic purposes, for example, simultaneous imaging and therapy can be carried out on cancer cells by using their luminescent properties and the in situ generation of reactive oxidative species (ROS) upon excitation in the NIR range. In the presence of CNDs, NIR remote activation induces the in vitro killing of U251MG cells. Through the use of flow imaging cytometry, we have been able to successfully map and quantify the different types of cell deaths induced by the presence of intracellular superoxide anions (. O2 - ) and hydrogen peroxide (H2 O2 ) ROS generated in situ upon NIR irradiation.