Antimonene Quantum Dots: Synthesis and Application as Near‐Infrared Photothermal Agents for Effective Cancer Therapy

Photothermal therapy (PTT) has shown significant potential for cancer therapy. However, developing nanomaterials (NMs)‐based photothermal agents (PTAs) with satisfactory photothermal conversion efficacy (PTCE) and biocompatibility remains a key challenge. Herein, a new generation of PTAs based on two‐dimensional (2D) antimonene quantum dots (AMQDs) was developed by a novel liquid exfoliation method. Surface modification of AMQDs with polyethylene glycol (PEG) significantly enhanced both biocompatibility and stability in physiological medium. The PEG‐coated AMQDs showed a PTCE of 45.5 %, which is higher than many other NMs‐based PTAs such as graphene, Au, MoS₂, and black phosphorus (BP). The AMQDs‐based PTAs also exhibited a unique feature of NIR‐induced rapid degradability. Through both in vitro and in vivo studies, the PEG‐coated AMQDs demonstrated notable NIR‐induced tumor ablation ability. This work is expected to expand the utility of 2D antimonene (AM) to biomedical applications through the development of an entirely novel PTA platform.     

Ag@TiO2 Nanoprisms with Highly Efficient Near‐Infrared Photothermal Conversion for Melanoma Therapy

Melanoma is a primary reason of death from skin cancer and associated with high lethality. Photothermal therapy (PTT) has been developed into a powerful cancer treatment technique in recent years. Here, we created a low‐cost and high‐performance PTT agent, Ag@TiO₂ NPs, which possesses a high photothermal conversion efficiency of ≈65 % and strong near‐infrared (NIR) absorption about 808 nm. Ag NPs were synthesized using a two‐step method and coated with TiO₂ to obtain Ag@TiO₂ NPs by a facile sol‐gel method. Because of the oxide, Ag@TiO₂ NPs exhibit remarkable high photothermal conversion efficiencies and biocompatibility in vivo and in vitro. Cytotoxicity and therapeutic efficiency of photothermal cytotoxicity of Ag@TiO₂ NPs were tested in B16‐F10 cells and C57BL/6J mice. Under light irradiation, the elevated temperature causes cell death in Ag NPs‐treated (100 μg mL^?1) cells in vitro (both p<0.01). In the case of subcutaneous melanoma tumor model, Ag@TiO₂ NPs (100 μg mL^?1) were injected into the tumor and irradiated with a 808 nm laser of 2 W cm^?2 for 1 minute. As a consequence, the tumor volume gradually decreased by NIR laser irradiation with only a single treatment. The results demonstrate that Ag@TiO₂ NPs are biocompatible and an attractive photothermal agent for cutaneous melanoma by local delivery.     

Algae Extraction Controllable Delamination of Vanadium Carbide Nanosheets with Enhanced Near‐Infrared Photothermal Performance

The two‐dimensional (2D) vanadium carbide (V₂C) MXene has shown great potential as a photothermal agent (PTA) for photothermal therapy (PTT). However, the use of V₂C in PTT is limited by the harsh synthesis condition and low photothermal conversion efficiency (PTCE). Herein, we report a completely different green delamination method using algae extraction to intercalate and delaminate V₂AlC to produce mass V₂C nanosheets (NSs) with a high yield (90 %). The resulting V₂C NSs demonstrated good structural integrity and remarkably high absorption in near infrared (NIR) region with a PTCE as high as 48 %. Systemic in vitro and in vivo studies demonstrate that the V₂C NSs can serve as efficient PTA for photoacoustic (PA) and magnetic resonance imaging (MRI)‐guided PTT of cancer. This work provides a cost‐effective, environment‐friendly, and high‐yielding disassembly approach of MAX, opening a new avenue to develop MXenes with desirable properties for a myriad of applications.     

Algae Extraction Controllable Delamination of Vanadium Carbide Nanosheets with Enhanced Near-Infrared Photothermal Performance

The two-dimensional (2D) vanadium carbide (V₂C) MXene has shown great potential as a photothermal agent (PTA) for photothermal therapy (PTT). However, the use of V₂C in PTT is limited by the harsh synthesis condition and low photothermal conversion efficiency (PTCE). Herein, we report a completely different green delamination method using algae extraction to intercalate and delaminate V₂AlC to produce mass V₂C nanosheets (NSs) with a high yield (90 %). The resulting V₂C NSs demonstrated good structural integrity and remarkably high absorption in near infrared (NIR) region with a PTCE as high as 48 %. Systemic in vitro and in vivo studies demonstrate that the V₂C NSs can serve as efficient PTA for photoacoustic (PA) and magnetic resonance imaging (MRI)-guided PTT of cancer. This work provides a cost-effective, environment-friendly, and high-yielding disassembly approach of MAX, opening a new avenue to develop MXenes with desirable properties for a myriad of applications.     

Highly biocompatible BSA-MnO2 nanoparticles as an efficient near-infrared photothermal agent for cancer therapy

In this work, we reported a facile, one-pot method to synthesis of bovine serum albumin (BSA)-reduced and stabilized MnO₂ nanoparticles (BSA-MnO₂ NPs) with good aqueous dispersibility and high biocompatibility. And we also showed for the first time that BSA-MnO₂ NPs displayed superior near infrared (NIR) photothermal efficiency and photostability which demonstrated as a novel class of photothermal antitumor agent.     

Photothermal performance of MFe2O4 nanoparticles

Photothermal therapy (PTT) has emerged as one of the promising cancer therapy approaches. As a representative photothermal agent (PTA), magnetite possesses many advantages such as biodegradability and biocompatibility. However, photothermal instability hampers its further application. Herein, we systematically synthesized three kinds of ferrite nanoparticles and detailedly investigated their photothermal effect. Compared with Fe₃O₄ and MnFe₂O₄ nanoparticles, ZnFe₂O₄ nanoparticles exhibited a superior photothermal effect. After preservation for 70 days, the photothermal effect of Fe₃O₄ and MnFe₂O₄ nanoparticles observably declined while ZnFe₂O₄ nanoparticles showed slight decrease. Furthermore, in vitro experiment, ZnFe₂O₄ nanoparticles showed little toxicity to cells and achieved outstanding effect in killing cancer cells under NIR laser irradiation. Overall, through synthesizing and studying three kinds of ferrite MFe₂O₄ nanoparticles, we obtained ferrites as PTAs and learned about their changing trend in photothermal effect, expecting it can inspire further exploration of photothermal agents.     

Linker‐free Gold Nanoparticle Superstructure Coated with Poly(dopamine) by Site‐Specific Polymerization for Amplifying Photothermal Cancer Therapy

Although linker‐free Au nanoparticle superstructures (AuNPSTs) have demonstrated to have satisfactory photothermal conversion efficiency owing to their enhanced visible‐near‐infrared absorption caused by the interparticle coupling, they cannot be used directly for in vivo photothermal therapy (PTT) of cancer because of poor stability. To address this issue, we herein propose a polymer‐coating strategy, dressing AuNPST on a poly(dopamine) (PDA) coat, and successfully investigate the in vivo PTT effect of AuNPSTs. By employing Triton X‐100 as an emulsifier for the formation of AuNPSTs, dopamine was site‐specifically polymerized around each AuNPST by the interaction between ?OH of Triton X‐100 and ?NH₂ of dopamine. As‐fabricated AuNPST/PDA has a sphere‐like shape with an average diameter of ～106 nm and the PDA shell is about 10 nm PDA thick. The AuNPST/PDA shows enhanced durability to heat, acid, and alkali compared with bare AuNPST. Also, under 808 nm laser irradiation, AuNPST/PDA shows photothermal conversion efficiency of ～33%, higher than bare AuNPST (～23%). Significantly, AuNPST/PDA can be used as in‐vitro and in‐vivo PTT agent and shows excellent therapeutic efficacy for tumor ablation thanks to its enhanced stability and biocompatibility, indicative of its potential practicability in clinical PTT.     

Graphene nanoribbon-based supramolecular ensembles with dual-receptor targeting function for targeted photothermal tumor therapy

Triple negative breast cancer (TNBC) is one of the most malignant subtypes of breast cancer. Here, we report the construction of graphene nanoribbon (GNR)-based supramolecular ensembles with dual-receptor (mannose and α_vβ₃ integrin receptors) targeting function, denoted as GNR-Man/PRGD, for targeted photothermal treatment (PTT) of TNBC. The GNR-Man/PRGD ensembles were constructed through the solution-based self-assembly of mannose-grafted GNRs (GNR-Man) with a pyrene-tagged α_vβ₃ integrin ligand (PRGD). Enhanced PTT efficacies were achieved both in vitro and in vivo compared to that of the non-targeting equivalents. Tumor-bearing live mice were administered (tail vein) with GNR-Man/PRGD and then each mice group was subjected to PTT. Remarkably, GNR-Man/PRGD induced complete ablation of the solid tumors, and no tumor regrowth was observed over a period of 15 days. This study demonstrates a new and promising platform for the development of photothermal nanomaterials for targeted tumor therapy.

Dual receptor-targeting supramolecular glycomaterials are constructed based on graphene nanoribbons for the targeted photothermal therapy of triple-negative breast cancer in vivo.     

UCNP–Bi2Se3 Upconverting Nanohybrid for Upconversion Luminescence and CT Imaging and Photothermal Therapy

Non-invasive theranostics that integrate the advantages of multimodality imaging and therapeutics have great potential in the field of biomedicine. Herein, a new nanohybrid based on Bi₂Se₃-conjugated upconversion nanoparticles (UCNPs) has been successfully developed through a simple in situ growth strategy. Under 808 nm near-infrared laser irradiation, the UCNPs can emit bright visible light, whereas the Bi₂Se₃ nanomaterial exhibits efficient photothermal conversion capacity. Moreover, the as-synthesized UCNP–Bi₂Se₃ nanohybrid exhibits efficient cell upconversion luminescence (UCL), reasonable CT imaging, and admirable cancer cell ablation capacity, further emphasizing the efficiency of this strategy for simultaneous UCL imaging and photothermal therapy. The designed theranostic strategy guided by dual-modal imaging endowed with real-time dynamic monitoring, remote controllability, and non-invasiveness makes the UCNP–Bi₂Se₃ nanohybrid an ideal candidate for non-invasive multimodal imaging-guided photothermal therapy for the precise diagnosis and treatment of cancer.     

Engineering J-aggregates for NIR-induced meso-CF3-BODIPY nanoparticles by activated apoptosis mechanism in photothermal therapy

Forming J-aggregates by organic monomer is a fascinating strategy to urge spectroscopic redshift with respect to that of the monomer. Herein, we designed 1,7-diphenyl-substituted meso–CF₃-BDP monomer confirmed by X-ray crystallographic analysis. The low-barrier rotation of the –CF₃group in meso–CF₃-BDP1 significantly enhances the non-radiative efficiency, and the photothermal conversion efficiency(PCE) of the self-assembled nanoparticles(1-NPs: λabs= 746 nm) by J...     

A Light-Responsive Injectable Hydrogel with Remodeling Tumor Microenvironment for Light-Activated Chemodynamic Therapy

Chemodynamic therapy (CDT) based on Fenton-like reaction is often limited by the tumor microenvironment (TME), which has insufficient hydrogen peroxide, and single CDT treatment is often less efficacious. To overcome these limitations, a hydrogel-based system is designed to enhance the redox stress (EOH) by loading the composite nanomaterial Cu-Hemin-Au, into the agarose hydrogels. The hydrogels can reach the tumor site upon intratumoral injection, and then coagulate and stay for extended period. Once irradiated with near-infrared light, the Cu-Hemin-Au act as a photothermal agent to convert the light energy into heat, and the EOH gradually heated up and softened, releasing the Cu-Hemin-Au residing in it to achieve photothermal therapy (PTT). Benefiting from the glucose oxidase (GOx)-like activity of the Au nanoparticles, glucose in the tumor cells is largely consumed, and hydrogen peroxide (H₂O₂) is generated in situ, and then Cu-Hemin-Au react with sufficient H₂O₂ to generate a large amount of reactive oxygen species, which promote the complete inhibition of tumor growth in mice during the treatment cycle. The hydrogel system for the synergistic enhancement of oxidative stress achieves good PTT/CDT synergy, providing a novel inspiration for the next generation of hydrogels for application in antitumor therapy.     

类石墨烯二硫化钼及其在光电子器件上的应用

由单层或几层二硫化钼构成的类石墨烯二硫化钼(graphene-like MoS₂)是一种具有类似石墨烯结构和性能的新型二维(2D)层状化合物, 近年来以其独特的物理、化学性质而成为新兴的研究热点. 本文综述了近年来类石墨烯二硫化钼常见的几种制备方法, 包括以微机械力剥离、锂离子插层和液相超声法等为主的“自上而下”的剥离法, 以及以高温热分解、水热法等为主的“自下而上”的合成法; 介绍了其常用的结构表征方法, 包括原子力显微镜(AFM)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和拉曼光谱等; 概述了类石墨烯二硫化钼的紫外-可见(UV-Vis)吸收、荧光发射等基本光物理性质及其相关机理; 总结了类石墨烯二硫化钼在二次电池、场效应晶体管、传感器、有机电致发光二极管和电存储等光电子器件领域的应用原理及其研究进展, 展望了这类新型二维层状化合物的研究前景.     

CuS nanodots-loaded biohybrid magnetic helical microrobots with enhanced photothermal performance

Magnetic helical microrobots swimming at low Reynolds numbers have attracted much interest because of their great potentials for biomedical applications. However, to endow them with sophisticated function integration toward targeted disease treatment still remains a major challenge. Here, we proposed a novel strategy of using Spirulina scaffolds to fabricate biohybrid magnetic helical microrobot (BMHM) with enhanced photothermal performance to fight against cancer cells and pathogenic bacteria. For the first time, CuS nanodots were densely and uniformly loaded intracellularly inside Spirulina cells after permeabilization, and Fe₃O₄ nanoparticles were subsequently deposited on the cell walls for magnetization. The BMHMs could be actuated forward at a high velocity and flexibly steered under rotating magnetic fields. Rapid and great photothermal temperature raise with robust cycling stability was achieved under 808 nm near-infrared laser irradiation. The BMHMs showed good biocompatibility with minor toxicity to HeLa cancer cells and Escherichia coli bacteria. Moreover, significant photothermal performance was further verified via a series of experiments for anticancer therapy and bacteria killing. Because of the remarkable features and facile cost-effective fabrication, the BMHMs demonstrated great potentials as an integrated microrobot platform for future anticancer and antibacteria applications.     

Novel photo-theranostic GdB6 nanoparticles for fluorescence imaging and NIR-photothermal therapy

The development of multifunctional theranostic nano-agents is an important resolution for personalized treatment of cancer. In this work, we synthesized a new kind of gadolinium boride nanoparticles (GBN) by a microwave-assisted chemical etching method, and discovered their optical characteristics including fluorescence imaging and near-infrared (NIR) photothermal conversion capability. Bright greenishyellow fluorescence enabled for intracellular localization, while effective NIR-photothermal conversion supported photothermal therapy (PTT). In vitro and in vivo results indicated that GBN exhibited a superior antitumor performance and high biocompatibility. This study demonstrated a promising multifunctional theranostic nanoplatform for cancer treatment.     

Two‐Dimensional Nanomaterials for Photothermal Therapy

Two‐dimensional (2D) nanomaterials are currently explored as novel photothermal agents because of their ultrathin structure, high specific surface area, and unique optoelectronic properties. In addition to single photothermal therapy (PTT), 2D nanomaterials have demonstrated significant potential in PTT‐based synergistic therapies. In this Minireview, we summarize the recent progress in 2D nanomaterials for enhanced photothermal cancer therapy over the last five years. Their unique optical properties, typical synthesis methods, and surface modification are also covered. Emphasis is placed on their PTT and PTT‐synergized chemotherapy, photodynamic therapy, and immunotherapy. The major challenges of 2D photothermal agents are addressed and the promising prospects are also presented.     

Water-Soluble Fe(II) Complexes for Theranostic Application: Synthesis,Photoacoustic Imaging,and Photothermal Conversion

Significant effort focused on developing photoactivatable theranostics for localized image guided therapy of cancer by thermal ablation. In this context iron complexes were recently identified as photoactivatable theranostic agents with adequate biocompatibility and body clearance. Herein, a series of Fe^II complexes bearing polypyridine or N-heterocyclic carbenes is reported that rely on rational complex engineering to red-shift their MLCT based excited-state deactivation via a straightforward approach. The non-radiative decay of their MLCT upon irradiation is exploited for theranostic purposes by combining both tracking in photoacoustic imaging (PA) and photothermal therapy (PTT). The influence of structural modifications introduced herein on the solubility and stability of the complexes in biorelevant aqueous media is discussed. The relationship between complexes’ design, production of contrast in photoacoustic and photothermal efficiency are explored to develop tailored PA/PTT theranostic agents.     

Autocatalytic polymerization of selenium/polypyrrole nanocomposites as functional theranostic agents for multi-spectral photoacoustic imaging and photothermal therapy of tumor

The synchronization of diagnosis and treatment is a new trend in cancer treatment. Photoacoustic imaging (PAI) and photothermal therapy (PTT) are recognized as one of the perfect combinations. The autocatalytic polymerization of selenium/polypyrrole (Se@PPy) nanocomposites with a wide-absorption band at near-infrared region (NIR, 800 nm) has been developed in this paper. The wide optical absorption characteristics enable Se@PPy nanocomposites to achieve multi-spectral PAI. Ex vivo experiments show desirable photoacoustic ability of the Se@PPy nanocomposites at wavelengths ranging from 700 nm to 900 nm, which is better than that of commercial indocyanine green (ICG). Se@PPy nanocomposites have high photothermal conversion efficiency up to 36.3% as well as excellent photo-thermal stability. In vitro cytotoxicity test demonstrates that the Se@PPy nanocomposites have good bio-safety. Furthermore, the feasibility of Se@PPy nanocomposites for enhancing multi-spectral PAI guided PTT was verified on 4T1 tumor-bearing nude mice. Our results indicate that Se@PPy nanocomposites could be used as an effective theranostic agent for near-infrared light-mediated PAI and PTT of tumor.     

Polyethylene glycol phospholipids encapsulated silicon 2,3-naphthalocyanine dihydroxide nanoparticles (SiNcOH-DSPEPEG(NH2) NPs) for single NIR laser induced cancer combination therapy

Currently, the combination of photothermal therapy (PTT) and photodynamic therapy (PDT) has emerged as a powerful technique for cancer treatment. However, most examples of combined PTT and PDT reported use multi-component nanocomposites under excitation of separate wavelength, resulting in complex treatment process. In this work, a novel theranostic nanoplatform (SiNcOH-DSPE-PEG(NH₂) NPs) has been successfully developed by coating silicon 2,3-naphthalocyanine dihydroxide (SiNcOH) with DSPE-PEG and DSPE-PEG-NH₂ for photoacoustic (PA) imaging-guided PTT and PDT tumor ablation for the first time. The as-prepared single-agent SiNcOH-DSPE-PEG(NH₂) NPs not only have good water solubility and biocompatibility, but also exhibit high photothermal conversion efficiency and singlet oxygen generation capability upon 808 nm NIR laser irradiation. In addition, owing to their high absorption at NIR region, the SiNcOH-DSPE-PEG(NH₂) NPs can also be employed as an effective diagnostic nanoagent for photoacoustic (PA) imaging. In vitro and in vivo experimental results clearly indicated that the simultaneously combined PTT and PDT under the guidance of PA imaging with single NIR laser excitation can effectively kill cancer cells or eradicate tumor tissues. Taking facile synthesis and high efficiency in cancer treatment by SiNcOH-DSPE-PEG(NH₂) NPs into consideration, our study provides a promising strategy to realize molecular imaging-guided combination therapy.     

Adhesive graphene grown on bioceramics with photothermal property

Recently, graphene has been applied to modify biomaterials due to excellent physicochemical property and biocompatibility. However, some problems still exist especially the weak binding force between graphene and other biomaterials. Herein, a promising platform with photothermal property was constructed by fabricating the adhesive graphene in situ on the surface of β-tricalcium phosphate (β-Ca₃(PO₄)₂, β-TCP) bioceramics using chemical vapor deposition (CVD). The result of ultrasonic cleaning treatment of graphene modified β-TCP (G-TCP) demonstrated that the prepared graphene coating could firmly modified on β-TCP due to the occurrence of carbothermal reduction on the ceramic surface to promote the nucleation and growth of graphene. G-TCP composites exhibited excellent photothermal effects when irradiated with 808 nm near-infrared laser (NIR). The photothermal effect of G-TCP composites could induce more than 90% of osteosarcoma cell (MNNG) death in vitro. These results confirmed that the graphene could be successfully fabricated in situ on the surface of β-TCP by CVD method, and exhibited high firmness and excellent photothermal performance, revealing a promising application in the photothermal therapy of bone tumors.     

A Multifunctional Biomaterial with NIR Long Persistent Phosphorescence,Photothermal Response and Magnetism

There are many reports on long persistent phosphors (LPPs) applied in bioimaging. However, there are few reports on LPPs applied in photothermal therapy (PTT), and an integrated system with multiple functions of diagnosis and therapy. In this work, we fabricate effective multifunctional phosphors Zn₃Ga₂SnO₈: Cr³⁺, Nd³⁺, Gd³⁺ with NIR persistent phosphorescence, photothermal response and magnetism. Such featured materials can act as NIR optical biolabels and magnetic resonance imaging (MRI) contrast agents for tracking the early cancer cells, but also as photothermal therapeutic agent for killing the cancer cells. This new multifunctional biomaterial is expected to open a new possibility of setting up an advanced imaging‐guided therapy system featuring a high resolution for bioimaging and low side effects for the photothermal ablation of tumors.