High Photothermal Conversion Efficiency Research Articles

Effective photothermal-photodynamic treatment of hepatocellular carcinoma based on polydopamine-coated mesoporous silica nanoparticles

The lack of tumor targeting ability and the ineffectiveness of single treatment modalities are two obstacles in the treatment of hepatocellular carcinoma (HCC). Herein, mesoporous silica nanoparticles (MSNs) with different sizes (MSN100 and MSN50) were synthesized and functionalized with polydopamine (PDA), hypericin B (HB), and arginine-glycine-aspartic acid (RGD) peptides for combined photothermal therapy (PTT) and photodynamic therapy (PDT) of HCC targeting αvβ3 integrin. MSN@PDA-RGD-HB were characterized by various techniques and showed selective drug release, high photothermal conversion efficiency, and reactive oxygen species (ROS) generation under laser irradiation. MSN100@PDA-RGD-HB exhibited higher cellular uptake and HCC toxicity than MSN50@PDA-RGD-HB in vitro, and specifically targeted HCC cells over normal cells. MSN100@PDA-RGD-HB demonstrated high biocompatibility in vivo, as confirmed by the hemolytic test and H&E staining. Importantly, MSN100@PDA-RGD-HB achieved a synergistic effect of PTT and PDT for HCC treatment in mice xenograft tumor model. Therefore, MSN100@PDA-RGD-HB has great potential for tumor therapy in the future.

PEGylated chitosan-coated nanophotosensitizers for effective cancer treatment by photothermal-photodynamic therapy combined with glutathione depletion

The combination of photothermal therapy (PTT) and photodynamic therapy (PDT) has emerged as a promising strategy for cancer treatment. However, the poor photostability and photothermal conversion efficiency (PCE) of organic small-molecule photosensitizers, and the intracellular glutathione (GSH)-mediated singlet oxygen scavenging largely decline the antitumor efficacy of PTT and PDT. Herein, a versatile nanophotosensitizer (NPS) system is developed by ingenious incorporation of indocyanine green (ICG) into the PEGylated chitosan (PEG-CS)-coated polydopamine (PDA) nanoparticles via multiple π-π stacking, hydrophobic and electrostatic interactions. The PEG-CS-covered NPS showed prominent colloidal and photothermal stability as well as high PCE (ca 62.8 %). Meanwhile, the Michael addition between NPS and GSH can consume GSH, thus reducing the GSH-induced singlet oxygen scavenging. After being internalized by CT26 cells, the NPS under near-infrared laser irradiation produced massive singlet oxygen with the aid of thermo-enhanced intracellular GSH depletion to elicit mitochondrial damage and lipid peroxide formation, thus leading to ferroptosis and apoptosis. Importantly, the combined PTT and PDT delivered by NPS effectively inhibited CT26 tumor growth in vivo by light-activated intense hyperthermia and redox homeostasis disturbance. Overall, this work presents a new tactic of boosting antitumor potency of ICG-mediated phototherapy by PEG-CS-covered NPS.

Succinct NIR-II absorbed croconic acid-julolidine molecule uniting Fe(III)-quercetin complex for efficient mild photothermal therapy of oropharyngeal carcinoma

The development of non-invasive mild photothermal therapy (MPTT) in combating oropharyngeal carcinoma (OC) can bring safe and effective for patients, and keep maximum preservation of oral function. In this study, we successfully synthesized a novel croconic acid-julolidine molecule (Cro-Jul) with broad absorption in the second near-infrared (NIR-II, 900–1700 nm) region, which is accompanied with high photothermal conversion efficiency (PCE) and controllable photothermal capacity. By systematically molecular theoretical calculation, the NIR-II optical properties of Cro-Jul and its photothermal conversion mechanism were analyzed. Besides, a coordination bond between quercetin (Qu) and Fe(III) was created to form a Fe(III)-Qu complex that not only can enhance MPTT by reducing heat shock proteins (HSPs) expression but also can introduce ferroptosis/chemodynamic therapy (CDT) for better therapeutic effect. By incorporating Cro-Jul and Fe(III)-Qu with DSPE-PEG2000, the multifunctional Fe(III)-Qu/CJ nanosystem was formed with an impressive PCE of 48.96 % under 980 nm irradiation, and the released Qu from the nanosystem effectively suppresses HSP70 expression during MPTT progress. Concurrently, liberated Fe(III) from the nanosystem interacts with intracellular glutathione and H2O2, inducing ferroptosis and CDT in tumor cells, ultimately enhancing apoptosis. Consequently, this study introduces a novel organic Cro-Jul molecule with Fe(III)-Qu nanosystem that combines ferroptosis, CDT, and NIR-II MPTT guided by photoacoustic imaging, offering significant potential for future clinical applications in OC treatment.

Near-Infrared Light-Driving Organic Photothermal Agents with an 88.9% Photothermal Conversion Efficiency for Image-Guided Synergistic Phototherapy.

Photothermal agents (PTAs) with desirable near-infrared (NIR) absorption and excellent photothermal conversion efficiency (PCE) are ideal candidates for cancer treatment. However, numerous PTAs still require high-intensity and long-duration laser irradiation to completely ablate the tumor during the photothermal therapy (PTT) process, resulting in light damage to healthy skin and tissue as well as limiting their biomedical applications. Integrating intense NIR absorption and high PCE into a single small-molecule PTA is an important prerequisite for realizing efficient PTT, but is a serious challenge. Herein, a series of donor-acceptor type PTAs (CC1 to NC4) are designed through a molecular engineering strategy. Theoretical calculations and experimental results show that the NIR absorption and photothermal effect from CC1 to NC4 are significantly enhanced as expected. Notably, NC4 nanoparticles exhibit intense NIR absorption, superhigh PCE of up to 88.9% for PTT, photoacoustic imaging and photothermal imaging, and effective reactive oxygen species generation for photodynamic therapy (PDT). The superior PTT/PDT synergistic phototherapeutic efficacy is well demonstrated by the complete elimination of tumor in vivo upon one-time, low-intensity, and short-duration laser irradiation (808nm, 330mW cm-2, and 3min). This work provides a valuable guideline for rational design of PTAs for cancer phototherapy.

One-Pot Synthesis of Luminescent and Photothermal Carbon Boron-Nitride Quantum Dots Exhibiting Cell Damage Protective Effects.

Zero-dimensional boron nitride quantum dots (BNQDs) are arousing interest for their versatile optical, chemical, and biochemical properties. Introducing carbon contents in BNQDs nanostructures is a great challenge to modulate their physicochemical properties. Among the carbon moieties, phenolic groups have attracted attention for their biochemical properties and phenol-containing nanomaterials are showing great promise for biomedical applications. Herein, the first example of direct synthesis of water dispersible BNQDs exposing phenolic and carboxylic groups is presented. The carbon-BNQDs are prepared in a single-step by solvent-assisted reaction of urea with boronic reagents and are characterized by optical absorption, luminescence, Raman, Fourier transform infrared and NMR spectroscopy, X-ray photoelectron spectroscopy, dynamic light scattering, and atomic force microscopy. The carbon-BNQDs exhibit nanodimension, stability, high photothermal conversion efficiency, pH-responsive luminescence and Z-potential. The potential of the carbon-BNQDs to provide photothermal materials in solid by embedding in agarose substrate is successfully investigated. The carbon-BNQDs exhibit biocompatibility on colorectal adenocarcinoma cells (Caco-2) and protective effects from chemical and oxidative stress on Caco-2, osteosarcoma (MG-63), and microglial (HMC-3) cells. Amplicon mRNA-seq analyses for the expression of 56 genes involve in oxidative-stress and inflammation are performed to evaluate the molecular events responsible for the cell protective effects of the carbon-BNQDs.

Acceptor-donor-acceptor type organic photothermal agents with enhanced NIR absorption and photothermal conversion effect for cancer photothermal therapy

Numerous photothermal agents (PTAs) require high-intensity and long-duration laser excitation for photothermal therapy (PTT), resulting in light damage to healthy skin and tissue as well as limiting their biomedical applications. Integrating desirable near-infrared (NIR) absorption and high photothermal conversion efficiency (PCE) into a single small-molecule PTA is an important prerequisite for realizing efficient PTT, but is a serious challenge. Herein, through molecular engineering strategy, an acceptor-donor-acceptor (A-D-A) type PTA (ADA3) was readily developed for 808 nm laser-driving photothermal imaging and PTT of tumor. Theoretical calculations and experiment results show molecular engineering strategy is significant in regulating the structure and energy gap of PTAs, so as to effectively induce a narrow band gap for NIR absorption and further optimize photothermal properties. ADA3 possesses molar extinction coefficient of 3.1 × 104 M−1 cm−1 at 808 nm, followed being assembled into nanoparticles, ADA3-NPs show high PCE of 80.3%. In vivo experiments indicate that ADA3-NPs have excellent antitumor capability under one-time, low-intensity and short-duration (808 nm, 330 mW/cm2, 3 min) laser irradiation. Therefore, this work definitely exemplifies the enormous potential of molecular engineering strategy and provides an effective method for developing small-molecule PTAs.

Scattered Co-anchored MoS2 synergistically boosting photothermal capture and storage of phase change materials

Pristine phase change materials (PCMs) suffer from inherent deficiencies of poor solar absorption and photothermal conversion. Herein, we proposed a strategy of co-incorporation of zero-dimensional (0D) metal nanoparticles and two-dimensional (2D) photothermal materials in PCMs for efficient capture and conversion of solar energy into thermal energy. Highly scattered Co-anchored MoS2 nanoflower cluster serving as photon and phonon triggers was prepared by in-situ hydrothermal growth of ZIF67 polyhedron on 2D MoS2 and subsequent high-temperature carbonization. After encapsulating thermal storage unit (paraffin wax), the obtained composite PCMs integrated high-performance photothermal conversion and thermal energy storage capability. Benefiting from the synergistic enhancement of 0D Co nanoparticles with localized surface plasmon resonance effect, carbon layer with the conjugation effect and 2D MoS2 with strong solar absorption, composite PCMs exhibited a high photothermal conversion efficiency of 95.19%. Additionally, the resulting composite PCMs also demonstrated long-term thermal storage stability and durable structural stability after 300 thermal cycles. The proposed collaborative co-incorporation strategy provides some innovative references for developing next-generation photothermal PCMs in solar energy utilization.

CA IX-targeted Ag2S quantum dots bioprobe for NIR-II imaging-guided hypoxia tumor chemo-photothermal therapy

Hypoxia is the common characteristic of almost all solid tumors, which prevents therapeutic drugs from reaching the tumors. Therefore, the development of new targeted agents for the accurate diagnosis of hypoxia tumors is widely concerned. As carbonic anhydrase IX (CA IX) is abundantly distributed on the hypoxia tumor cells, it is considered as a potential tumor biomarker. 4-(2-Aminoethyl)benzenesulfonamide (ABS) as a CA IX inhibitor has inherent inhibitory activity and good targeting effect. In this study, Ag2S quantum dots (QDs) were used as the carrier to prepare a novel diagnostic and therapeutic bioprobe (Ag2S@polyethylene glycol (PEG)-ABS) through ligand exchange and amide condensation reaction. Ag2S@PEG-ABS can selectively target tumors by surface-modified ABS and achieve accurate tumor imaging by the near infrared-II (NIR-II) fluorescence characteristics of Ag2S QDs. PEG modification of Ag2S QDs greatly improves its water solubility and stability, and therefore achieves high photothermal stability and high photothermal conversion efficiency (PCE) of 45.17%. Under laser irradiation, Ag2S@PEG-ABS has powerful photothermal and inherent antitumor combinations on colon cancer cells (CT-26) in vitro. It also has been proved that Ag2S@PEG-ABS can realize the effective treatment of hypoxia tumors in vivo and show good biocompatibility. Therefore, it is a new efficient integrated platform for the diagnosis and treatment of hypoxia tumors.

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

AbstractThe 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.

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.

Synergistic Inter‐ and Intramolecular Aggregation of Dimeric Cyanine Dyes Affords Highly Efficient In Vivo Self‐Delivery and Photothermal Therapy

AbstractAdvancing photothermal therapy hinges on developing PTAs with robust in vivo delivery and therapeutic efficacy. However, effective molecular design approaches for high‐performance PTAs remain lacking. Herein a strategic design of dimeric heptamethine cyanine (Cy7) molecules is presented, covalently linked via ortho/meta/para‐phenyldithiol. These designs facilitate spontaneous nanoparticle assembly in water, attributed to efficient intermolecular aggregation, enhancing in vivo delivery. Additionally, aggregation between intramolecular Cy7 units promotes superior photothermal conversion efficiency (PCE) up to 74.1% for meta‐dimer. Remarkably, the para‐dimer variant not only achieves a high PCE of 61.1% but also exhibits the most effective pharmacokinetic profile, leading to unparalleled anticancer efficacy in vivo. This dual aggregation strategy, leveraging both inter‐ and intramolecular dynamics, equips dimeric Cy7 with superior self‐delivery and photothermal efficacy, offering a promising approach for the next generation of photothermal therapeutics.

Biosynthesis of CuTe Nanorods with Large Molar Extinction Coefficients for NIR-II Photoacoustic Imaging.

Photoacoustic imaging (PAI) in the second near-infrared region (NIR-II), due to deeper tissue penetration and a lower background interference, has attracted widespread concern. However, the development of NIR-II nanoprobes with a large molar extinction coefficient and a high photothermal conversion efficiency (PCE) for PAI and photothermal therapy (PTT) is still a big challenge. In this work, the NIR-II CuTe nanorods (NRs) with large molar extinction coefficients ((1.31 ± 0.01) × 108 cm-1·M-1 at 808 nm, (7.00 ± 0.38) × 107 cm-1·M-1 at 1064 nm) and high PCEs (70% at 808 nm, 48% at 1064 nm) were synthesized by living Staphylococcus aureus (S. aureus) cells as biosynthesis factories. Due to the strong light-absorbing and high photothermal conversion ability, the in vitro PA signals of CuTe NRs were about 6 times that of indocyanine green (ICG) in both NIR-I and NIR-II. In addition, CuTe NRs could effectively inhibit tumor growth through PTT. This work provides a new strategy for developing NIR-II probes with large molar extinction coefficients and high PCEs for NIR-II PAI and PTT.

Rotor-based image-guided therapy of glioblastoma

Glioblastoma (GBM), deep in the brain, is more challenging to diagnose and treat than other tumors. Such challenges have blocked the development of high-impact therapeutic approaches that combine reliable diagnosis with targeted therapy. Herein, effective cyanine dyes (IRLy) with the near-infrared two region (NIR-II) adsorption and aggregation-induced emission (AIE) have been developed via an “extended conjugation & molecular rotor” strategy for multimodal imaging and phototherapy of deep orthotopic GBM. IRLy was synthesized successfully through a rational molecular rotor modification with stronger penetration, higher signal-to-noise ratio, and a high photothermal conversion efficiency (PCE) up to ∼60%, which can achieve efficient NIR-II photo-response. The multifunctional nanoparticles (Tf-IRLy NPs) were further fabricated to cross the blood-brain barrier (BBB) introducing transferrin (Tf) as a targeting ligand. Tf-IRLy NPs showed high biosafety and good tumor enrichment for GBM in vitro and in vivo, and thus enabled accurate, efficient, and less invasive NIR-II multimodal imaging and photothermal therapy. This versatile Tf-IRLy nanosystem can provide a reference for the efficient, precise and low-invasive multi-synergistic brain targeted photo-theranostics. In addition, the “extended conjugation & molecular rotor” strategy can be used to guide the design of other photothermal agents.

Development of High-Performance and Multifunctional Nanoparticles Powered the Integrated Diagnosis and Treatment of Escherichia coli O157:H7.

Pathogenic diseases that trigger food safety remain a noteworthy concern due to substantial public health, economic, and social burdens worldwide. It is vital for developing an integrated diagnosis and treatment strategy for bacteria, which could achieve quick detection of pathogenic bacteria and the inhibition of multidrug-resistant bacteria. Herein, we reported an organic molecule (M-3) possessed strong light capture capacity, emerging a low energy gap and ΔEST. Subsequently, M-3 was integrated into a nanostructured system (BTBNPs) with excellent ROS generation, light absorption capability, and photothermal performance. Reactive oxygen species (ROS) generated by BTBNPs were mainly free radicals from a type I mechanism, and the high photothermal conversion efficiency of BTBNPs was 41.26%. Benefiting from these advantages of BTBNPs, BTBNPs could achieve a ∼99% antibacterial effect for Escherichia coli O157:H7 with 20 μM dosage and 5 min of irradiation. Furthermore, the limit of detection (LoD) of the proposed BTBNPs-LFIA (colorimetric and photothermal modalities) for detecting E. coli O157:H7 was 4105 and 419 CFU mL-1, respectively. Overall, this work is expected to provide a new and sophisticated perspective for integrated diagnosis and treatment systems regarding pathogenic bacteria.

Eudragit S100 coated nanodiamond-based nanoparticles as an oral chemo-photothermal delivery system for local treatment of colon cancer

Oral colonic nano-drug delivery system has received more and more attention in the treatment of colon cancer due to local precision treatment and reduction of drug system distribution. However, the complex and harsh gastrointestinal environment and the retention of nanoparticles in the colon limit its development. To this end, we designed Eudragit S100 (ES) coated nanoparticles (ES@PND-PEG-TPP/DOX). Polydopamine coated nanodiamond (PND) was modified with amino-functionalized polyethylene glycol (NH2-PEG-NH2) and triphenylphosphine (TPP) successively. Due to the high specific surface area of PND, it can efficiently load the model drug doxorubicin hydrochloride (DOX). In addition, PND also has high photothermal conversion efficiency, generating heat to kill cancer cells under near infrared (NIR) laser, realizing the combination of chemotherapy and photothermal therapy (CT-PTT). TPP modification enhanced nanoparticle uptake by colon cancer cells and prolonged preparations retention time at the colon. ES shell protected the drug from being destroyed and prevented the nanoparticles from sticking to the small intestine. Ex vitro fluorescence imaging showed that TPP modification can enhance the residence time of nanoparticles in the colon. In vivo pharmacodynamics demonstrated that CT-PTT group has the greatest inhibitory effect on tumor growth, which means that the nanocarrier has potential clinical value in the in-situ treatment of colon cancer.

Easy but Efficient: Facile Approach to Molecule with Theoretically Justified Donor-Acceptor Structure for Effective Photothermal Conversion and Intravenous Photothermal Therapy.

To accelerate the pace in the field of photothermal therapy (PTT), it is urged to develop easily accessible photothermal agents (PTAs) showing high photothermal conversion efficiency (PCE). As a proof-of-concept, hereby a conventional strategy is presented to prepare donor-acceptor (D-A) structured PTAs through cycloaddition-retroelectrocyclization (CA-RE) reaction, and the resultant PTAs give high PCE upon near-infrared (NIR) irradiation. By joint experimental-theoretical study, these PTAs exhibit prominent D-A structure with strong intramolecular charge transfer (ICT) characteristics and significantly twisting between D and A units which account for the high PCEs. Among them, the DMA-TCNQ exhibits the strongest absorption in NIR range as well as the highest PCE of 91.3% upon irradiation by 760-nm LED lamp (1.2W cm-2). In vitro and in vivo experimental results revealed that DMA-TCNQ exhibits low dark toxicity and high phototoxicity after IR irradiation along with nude mice tumor inhibition up to 81.0% through intravenous therapy. The findings demonstrate CA-RE reaction as a convenient approach to obtain twisted D-A structured PTAs for effective PTT and probably promote the progress of cancer therapies.

Cutting‐Edge Technology for Early Intervention in Myocardial Infarction: Portable Fingertips‐Based Immunobiosensor

AbstractEarly intervention in acute myocardial infarction can minimize myocardial damage and improve patient survival. Herein, a low‐cost device‐free portable immunobiosensing platform for flexible monitoring of immediate myocardial infarction is reported. CuS‐Pt nanofragments (CuS‐Pt NFs) with high photothermal conversion efficiency (≈26.41%) are synthesized by liquid‐phase polarity‐mediated synthesis. The CuS NFs are loaded in situ with platinum (Pt) nanoreactors using a solvothermal reduction strategy, which is employed to enhance the efficiency of gas production. The resulting CuS‐Pt nanocatalysts are encapsulated within liposomes for signal cascade amplification. Specifically, cardiac troponin I (cTn I), a target biomarker in serum, is captured on pre‐modified microtiter plates and formed into a classical sandwich model. The thermo‐chemically kinetically enhanced CuS‐Pt reactor is released through a one‐step chemical treatment and transferred to a closed gas generator. Under the excitation of a near‐infrared laser emitter, the internal pressure in the gas generator device increases with time and drives the carbon quantum dot solution in the connected hose. The moving distance shows a correlation with the target concentration. This work provides a new implementation for the development of low‐cost, efficient pressure immunosensors without the requirement of a readout device.

Enhancing Photothermal/Photodynamic Therapy for Glioblastoma by Tumor Hypoxia Alleviation and Heat Shock Protein Inhibition Using IR820-Conjugated Reduced Graphene Oxide Quantum Dots.

We use low-molecular-weight branched polyethylenimine (PEI) to produce cytocompatible reduced graphene oxide quantum dots (rGOQD) as a photothermal agent and covalently bind it with the photosensitizer IR-820. The rGOQD/IR820 shows high photothermal conversion efficiency and produces reactive oxygen species (ROS) after irradiation with near-infrared (NIR) light for photothermal/photodynamic therapy (PTT/PDT). To improve suspension stability, rGOQD/IR820 was PEGylated by anchoring with the DSPE hydrophobic tails in DSPE-PEG-Mal, leaving the maleimide (Mal) end group for covalent binding with manganese dioxide/bovine serum albumin (MnO2/BSA) and targeting ligand cell-penetrating peptide (CPP) to synthesize rGOQD/IR820/MnO2/CPP. As MnO2 can react with intracellular hydrogen peroxide to produce oxygen for alleviating the hypoxia condition in the acidic tumor microenvironment, the efficacy of PDT could be enhanced by generating more cytotoxic ROS with NIR light. Furthermore, quercetin (Q) was loaded to rGOQD through π-π interaction, which can be released in the endosomes and act as an inhibitor of heat shock protein 70 (HSP70). This sensitizes tumor cells to thermal stress and increases the efficacy of mild-temperature PTT with NIR irradiation. By simultaneously incorporating the HSP70 inhibitor (Q) and the in situ hypoxia alleviating agent (MnO2), the rGOQD/IR820/MnO2/Q/CPP can overcome the limitation of PTT/PDT and enhance the efficacy of targeted phototherapy in vitro. From in vivo study with an orthotopic brain tumor model, rGOQD/IR820/MnO2/Q/CPP administered through tail vein injection can cross the blood-brain barrier and accumulate in the intracranial tumor, after which NIR laser light irradiation can shrink the tumor and prolong the survival times of animals by simultaneously enhancing the efficacy of PTT/PDT to treat glioblastoma.

Light erasable surface-enhanced Raman scattering substrates based on the metallic molybdenum dioxide nanospheres

Surface-enhanced Raman scattering (SERS) is a powerful label-free technique for the identification of molecules and molecular structures at extremely low concentrations. However, in most cases, the analytes will remain on SERS substrates, making the substrate a disposable consumable. Here, we propose a light erasable SERS substrate based on the metallic molybdenum dioxide (MoO2) nanospheres. The MoO2 nanospheres present a remarkable localized surface plasmon resonance (LSPR) absorption peak centered at 800 nm. Profiting from the local field magnification induced by the LSPR, MoO2 exhibits excellent SERS detection sensitivity towards rhodamine 6 G (R6G), rhodamine B (RhB), methyl blue (MB), crystal violet (CV) and Malachite Green (MG), with a detection limit of 10−7 M and a maximum enhancement factor up to 5.4 × 104. Moreover, the metallic MoO2 nanospheres possess a high photothermal conversion efficiency of 70.1% and good photothermal stability. The temperature of the MoO2 surface can reach 438 °C under 808 nm laser irradiation with a power density of 2.5 W cm−2, exceeding the decomposition temperature of most organic molecules. Thus, the residual probe molecules can be completely removed from the MoO2 substrate in less than 7.5 min under laser irradiation without compromising its SERS sensitivity and reproducibility. We anticipate our work will pave a new avenue for the development of reusable and highly sensitive SERS substrates.

A Nanographene-Porphyrin Hybrid for Near-Infrared-Ii Phototheranostics.

Photoacoustic imaging (PAI)-guided photothermal therapy (PTT) in the second near-infrared (NIR-II, 1000-1700nm) window has been attracting attention as a promising cancer theranostic platform. Here, it is reported that the π-extended porphyrins fused with one or two nanographene units (NGP-1 and NGP-2) can serve as a new class of NIR-responsive organic agents, displaying absorption extending to ≈1000 and ≈1400nm in the NIR-I and NIR-II windows, respectively. NGP-1 and NGP-2 are dispersed in water through encapsulation into self-assembled nanoparticles (NPs), achieving high photothermal conversion efficiency of 60% and 69%, respectively, under 808 and 1064nm laser irradiation. Moreover, the NIR-II-active NGP-2-NPs demonstrated promising photoacoustic responses, along with high photostability and biocompatibility, enabling PAI and efficient NIR-II PTT of cancer in vivo.