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Low photothermal conversion efficiency restricts the antibacterial application of photothermal materials. In this work, two-dimensional carbon nanosheets (2D C) were prepared and decorated with Cu nanoparticles (2D C/Cu) by using a simple soluble salt template method combined with ultrasonic exfoliation. The photothermal conversion efficiency of 2D C/Cu system can be optimized by changing the content of Cu nanoparticles, where the 2D C/Cu2 showed the best photothermal conversion efficiency (η) of 65.05 % under 808 nm near-infrared light irradiation. In addition, the photothermal performance can affect the release behavior of Cu ions. This superior photothermal property combined with released Cu ions can endow this 2D hybrid material with highly efficient antibacterial efficacy of 99.97 % ± 0.01 %, 99.96 % ± 0.01 %, 99.97 % ± 0.01 % against Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus, respectively, because of the synergetic effect of photothermy and ion release. In addition, this 2D hybrid system exhibited good cytocompatibility. Hence, this study provides a novel strategy to enhance the photothermal performance of 2D materials and thus will be beneficial for development of antibiotics-free antibacterial materials with safe and highly efficient bactericidal activity.

The photoisomerization properties of azo derivatives have been widely used in the fields of materials and biology. One serious restriction to the development of functional azo-based materials is the necessity to trigger switching by UV light, which damage the corresponding surfaces and penetrate only partially through the matter. Therefore, developing the visible and near-infrared light activated azo switches can solve this problem. This review provides a summary of molecular design strategies for driving the isomerization of azo derivatives with visible light and near-infrared light: (1) smart design directly excited by visible light, (2) the addition of upconversion nanoparticles, (3) the employment of two-photon absorption, (4) indirect excitation in combination with metal sensitizer.

Background We investigated the therapeutic effect of targeting extracellular vesicles (EVs) loaded with indocyanine green (ICG) and paclitaxel (PTX) on glioma. Methods Raw264.7 cells were harvested to extract EVs for the preparation of ICG/PTX@RGE-EV by electroporation and click chemistry. We evaluated the success of modifying Neuropilin-1 targeting peptide (RGE) on the EV membrane of ICG/PTX@RGE-EV using super-resolution fluorescence microscopy and flow cytometry. Spectrophotometry and high performance liquid chromatography (HPLC) were implemented for qualitative and quantitative analysis of the ICG and PTX loaded in EVs. Photothermal properties of the vesicles were evaluated by exposing to 808-nm laser light. Western blot analysis, cell counting kit 8 (CCK-8), Calcein Acetoxymethyl Ester/propidium iodide (Calcein-AM/PI) staining, and flow cytometry were utilized for assessing effects of vesicle treatment on cellular behaviors. A nude mouse model bearing glioma was established to test the targeting ability and anti-tumor action of ICG/PTX@RGE-EV in vivo. Results Under exposure to 808-nm laser light, ICG/PTX@RGE-EV showed good photothermal properties and promotion of PTX release from EVs. ICG/PTX@RGE-EV effectively targeted U251 cells, with activation of the Caspase-3 pathway and elevated apoptosis in U251 cells through chemotherapy combined with hyperthermia. The anti-tumor function of ICG/PTX@RGE-EV was confirmed in the glioma mice via increased accumulation of PTX in the ICG/PTX@RGE-EV group and an increased median survival of 48 days in the ICG/PTX@RGE-EV group as compared to 25 days in the PBS group. Conclusion ICG/PTX@RGE-EV might actively target glioma to repress tumor growth by accelerating glioma cell apoptosis through combined chemotherapy-hyperthermia. Graphic Abstract

One of the difficulties in atherosclerosis treatment is that the ablation of inflammatory macrophages, repair of vascular endothelial injury, and anti-tissue proliferation should be considered. However, there are few studies that can solve the abovementioned problems simultaneously. Herein, we present a kind of near-infrared (NIR) light-driven multifunctional mesoporous/macroporous tubular micromotor which can rapidly target the damaged blood vessels and release different drugs. Their motion effect can promote themselves to penetrate into the plaque site, and the generated heat effect caused by NIR irradiation can realize the photothermal ablation of inflammatory macrophages. Furthermore, these micromotors can rapidly release the vascular endothelial growth factor for endothelialization and slowly release paclitaxel for antiproliferation to achieve synergistic treatment of atherosclerosis. In vivo results demonstrated that the micromotors can achieve a good therapeutic effect for atherosclerosis. This kind of micro/nanomotor technology with a complex porous structure for drug loading will bring a more potential treatment platform for the disease.

Novel near-infrared (NIR) light-induced bio-based shape memory polymers (SMPs) were prepared from copolymers of vanillin/furfurylamine-based benzoxazine monomer (V-fa monomer) and epoxidized castor oil (ECO). Incorporation of graphene nanoplatelets (GNPs) as photothermal fillers into the copolymers provided shape memory properties under near-infrared (NIR) light actuation. The effects of GNP content on photothermal, thermal, dynamic mechanical, morphology, and shape memory properties of the bio-based benzoxazine/epoxy copolymers (V-fa/ECO copolymers) were investigated. The results showed that the addition of GNPs significantly improved the photothermal, thermal, and dynamic mechanical properties of the copolymers. The uniform dispersion of 3 wt% GNPs in the V-fa/ECO copolymers resulted in the highest shape memory performance with shape fixity of 92% and shape recovery of 99% upon NIR light actuation. The recovery time decreased with the increment of GNP content, and the V-fa/ECO copolymers filled with GNPs displayed good execution in the repeated fold-deploy, in which the shape fixity and shape recovery values were close to the original specimen. Therefore, the outstanding properties of V-fa/ECO copolymers filled with GNPs had a potential to be excellent SMPs under NIR actuation.

Remote controllability and multiple-shape memory performance are two important functions for shape memory polymers (SMPs) in engineering applications, which are still a challenge to achieve via a facile approach. Herein, we synthesized a shape memory composite with near-infrared (NIR) light-induced triple-shape memory performance by in situ formation of iron tannate (FeTA) nanoparticles in cross-linked poly(ethylene-co-vinyl alcohol) (EVOH). EVOH possessed two transition temperatures enabling the composites with triple-shape memory behavior, while FeTA nanoparticles served as the photothermal conversion factor for NIR light-induced responsiveness. Because the light-induced triple-shape memory performance of the composite is highly dependent on its photothermal conversion property, the control of FeTA doping would also be an effective solution to prepare light-induced multiple-SMPs with various shape transformations. Moreover, the composites exhibited high light-driving recovery stress, which could lift burdens 1600 times heavier than their own weight, indicating their great potential as a smart soft actuator for various applications.

We report conjugated polymers consisting of boron formazanate in the main chains. By employing typical donor-type comonomers, such as fluorene and bithiophene, copolymers were prepared with the Mig...

Infectious diseases caused by bacteria are a global threat to the human health. Here, we propose a solvent “irrigation” technique to endow TiO2 nanotubes (NTs) to precisely modify with functional nanomaterials, and apply them in constructing a near-infrared (NIR) light controlled drug-delivery system for rapid necrosis of bacteria. In this design, the NIR stimuli-responsive functional shell is located on the external tube wall of TiO2 NT; the internal tube wall offers sufficient binding sites for drug loading. Using kanamycin as a model drug, we demonstrate that the reactive oxygen species generated in photocatalysis not only controllably release the loaded drug by scissoring the linked chains, but also effectively compromise bacteria membrane integrity by damaging the cell wall. Benefiting from the damages, antibiotics rapidly enter the bacteria and reach ≥99.9% reduction in Escherichia coli colony within only 2 h. Importantly, such a covalently conjugation-based delivery system can efficiently relieve radical-induced inflammation and cytotoxicity. This study provides an innovative design strategy for engineering delivery systems with tailorable components, enduring stimuli-response by multiple triggers.

Bufalin is efficacious in treating various tumors, however, the clinical application of which is restricted by the myocardial toxicity. Developing a smart synergetic delivery system is widely considered as a promising therapeutic strategy. To address this issue, a black phosphorus hybrid polypeptides hydrogel was designed to highly load bufalin, and achieved near-infrared (NIR)-controllable drug release with synergistic photothermal-chemo therapeutic effect. Black phosphorus nanosheets (BPNSs) and bufalin were co-loaded in temperature-sensitive supramolecular hydrogel to receive smart hybridization (BP-bufalin@SH). With NIR irradiation (1 W·cm−2), BP-bufalin@SH exhibited a rapid and large temperature increase and released bufalin via light-controllable manner, with which the side effects of bufalin were greatly decreased. Combined with photothermal-chemo therapeutic effect, BP-bufalin@SH could collapse the mitochondrial transmembrane potential resulting in the irreversible apoptosis of tumor cells, and realize a highly efficient in vivo tumor elimination with good biosafety and biocompatibility. This work provides a new hydrogel platform for controlling bufalin release, and thus further promotes the practical application on antitumor therapy.

Near-infrared (NIR) light-responsive materials had attracted much attention by virtue of their ability to employ abundant light sources to adapt their properties remotely and spatially in which development of novel NIR light-responsive fillers was the key factor. In this work, cellulose nanocrystals (CNCs) were coated with polydopamine (PDA) to endow these plant-derived nanofillers with good light absorption properties. In this work, PDA@CNC was incorporated into the poly(N-isopropylacrylamide) (PNIPAM) matrix to fabricate PDA@CNC/PNIAPM nanocomposite hydrogels with controllable performance in response to NIR stimuli. The PDA@CNC would not only serve as a reinforcement agent to mechanically toughen the hydrogels but also integrate considerable photothermal effect into the same system. As a result of fast NIR responsiveness and easily tailored photothermal properties, the 5-Fluorouracil (5-Fu) release behavior of the nanocomposite hydrogels could be remotely controlled with the assistance of a NIR laser. Besides, the nanocomposite hydrogel with Ag nanoparticles immobilized PDA@CNC (Ag/PDA@CNC) was demonstrated as a novel catalyst to tune the reduction rate of 4-nitrophenol (4-NP) upon NIR irradiation. Taken together, the modified CNCs would be alternative functional nanofillers for the construction of NIR light-responsive materials with controllable performance.

Photodynamic therapy has great potential for tumor ablation and the activation of antitumor immune responses. However, its overall therapeutic efficiency is often limited by the immunosuppressive tumor microenvironment. We developed a near-infrared light-excitable immunomodulating nano-photosensitizer (NeINP) that can improve reactive oxygen species production and regulate the immunosuppressive TME to improve photoimmunotherapy. The NeINP is composed of a photosensitive core and a pH-responsive polymer shell, which allows for NeINP loading and delivery of small-molecular immunomodulators to tumor sites for regulation of the immunosuppressive TME and effective photoimmunotherapy. Through the co-delivery of celecoxib and the NIR-triggered photodynamic core to tumors, the NeINP was shown to regulate the immunosuppressive TME and enhance antitumor immunity, leading to the elimination of residual tumor and reduction of metastasis and recurrence. The NeINP can be optimized to co-deliver other immunomodulators, and thus has potential as a universal platform for efficient, precise photoimmunotherapy.

A transformable upconversion MOF comprising a UCNP core and an azobenzene-based MOF shell is designed for NIR light-modulated chemotherapy. The dual Förster resonance energy transfers (FRETs) involved in this delivery system trigger the transformation of the MOF for drug release and prodrug activation, thus significantly inhibiting the tumor growth and metastasis.

Light-based theranostics have become indispensable tools in the field of cancer nanomedicine. Specifically, near infrared (NIR) light mediated imaging and therapy of deeply seated tumors using a single multi-functional nanoplatform have gained significant attention. To this end, several multi-functional nanomaterials have been utilized to tackle cancer and thereby achieve significant outcomes. The present review mainly focuses on the recent advances in the development of NIR light activatable multi-functional materials such as small molecules, quantum dots, and metallic nanostructures for the diagnosis and treatment of deeply seated tumors. The need for improved disease detection and enhanced treatment options, together with realistic considerations for clinically translatable nanomaterials will be the key driving factors for theranostic agent research in the near future. NIR-light mediated cancer imaging and therapeutic approaches offer several advantages in terms of minimal invasiveness, deeper tissue penetration, spatiotemporal resolution, and molecular specificities. Herein, we have reviewed the recent developments in NIR light responsive multi-functional nanostructures for phototheranostic applications in cancer therapy.

Research in novel materials has been extremely active over the past few decades, wherein a major area of interest has been nanoparticles with special optical properties. These structures can overcome some of the intrinsic limitations of contrast agents routinely used in medical practice, while offering additional functionalities. Materials that absorb or scatter near infrared light, to which biological tissues are partially transparent, have attracted significant attention and demonstrated their potential in preclinical research. In this review, we provide an at-a-glance overview of the most recent developments in near infrared nanoparticles that could have far-reaching applications in the life sciences. We focus on materials that offer additional functionalities besides diagnosis based on optical contrast: multiple imaging modalities (multimodal imaging), sensing of physical and chemical cues (multivariate diagnosis), or therapeutic activity (theranostics). Besides presenting relevant case studies for each class of optically active materials, we discuss their design and safety considerations, detailing the potential hurdles that may complicate their clinical translation. While multifunctional nanomaterials have shown promise in preclinical research, the field is still in its infancy; there is plenty of room to maximize its impact in preclinical studies as well as to deliver it to the clinics.

Currently, polyimine vitrimer is restricted by unitary functionality and poor responsiveness to external stimuli, thus showing limited potentials for broader applications as a kind of smart materia...

Bacterial infections are becoming a serious public health challenge because the abuse of antibiotics worldwide has caused bacterial resistance and the occurrence of superbugs. In this work, a new near-infrared (NIR) photoresponsive coating was constructed on Ti implant material, which was composed of MnO2, IR780 photosensitizer and polydopamine (PDA). Under the irradiation of 808 nm NIR light, the component of MnO2 in the coating exhibited high photothermal performance, and IR780 could be stimulated to generate ROS as a photosensitizer. The addition of PDA not only improved the cytocompatibility of the composite coating but also strengthened the light absorption ability of the system. Under the irradiation of 808 nm NIR light for 15 min, the composite coating killed 99.94% Staphylococcus aureus and 99.89% Escherichia coli on Ti plates. This rapid and highly effective bactericidal rate was ascribed to the synergistic effects of photothermal performance and photodynamic effect of the coatings excited by NIR light. Cell culture tests showed that PDA/IR780@MnO2–Ti had good cytocompatibility due to the excellent biocompatibility of PDA and nanostructured surface. Therefore, this surface system will be a very promising plateform to safely and effectively kill bacteria on biomedical devices and implants in a short time.

Photocontrolled therapeutic release holds great promise due to its versatile manipulability, superb spatiotemporal precision and minimal tissue invasiveness in biomedical purposes. However, most of light-responsive platforms thus far have relied on UV or visible light which substantially limit the potential applicability in living animals. In recent decades, near-infrared (NIR) light-mediated theranostic upconversion nanocomposites (UCNCs) that integrate conventional UV/Vis-sensitive materials and classic lanthanide-doped upconversion nanoparticles (UCNPs) have significantly promoted the development of deep-tissue photoreleasable therapeutics in vivo. Herein, we seek to review current NIR upconversion triggered photorelease techniques and their diverse applications in the biological regulation, as well as diseases therapy. In addition, the future perspectives and challenges for advancing UCNCs based NIR photoreleasable nanotherapeutics into clinical translations are proposed. Agency for Science, Technology and Research (A*STAR) Nanyang Technological University B.X. acknowledges the financial supports from NTU-AIT-MUV NAM/16001, Tier 1 RG5/18 (S), SSIJRI (203-A018003), MOE 2017-T2- 2-110, A*Star SERC A1983c0028 (M4070319), SPMS-M4082042.110 awarded in Nanyang Technological University (NTU), Singapore and National Natural Science Foundation of China (NSFC) (No. 51929201), China.

Near-infrared (NIR) photoinduced chemical processes are highly attractive for specific applications owing to the deep penetration of NIR into the nontransparent materials including biological and s...

Exported fresh intact pineapples must fulfill the minimum internal quality requirement of 12 degree brix. Even though near-infrared (NIR) spectroscopic approaches are promising to non-destructively and rapidly assess the internal quality of intact pineapples, these approaches involve expensive and complex NIR spectroscopic instrumentation. Thus, this research evaluates the performance of a proposed pre-dispersive NIR light sensing approach in non-destructively classifying the Brix of pineapples using K-fold cross-validation, holdout validation, and sensitive analysis. First, the proposed pre-dispersive NIR sensing device that consisted of a light sensing element and five NIR light emitting diodes with peak wavelengths of 780, 850, 870, 910, and 940 nm, respectively, was developed. After that, the diffuse reflectance NIR light of intact pineapples was non-destructively acquired using the developed NIR sensing device before their Brix values were conventionally measured using a digital refractometer. Next, an artificial neural network (ANN) was trained and optimized to classify the Brix values of pineapples using the acquired NIR light. The results of the sensitivity analysis showed that either one wavelength that was near to the water absorbance or chlorophyll band was redundant in the classification. The performance of the trained ANN was tested using new pineapples with the optimal classification accuracy of 80.56%. This indicates that the proposed pre-dispersive NIR light sensing approach coupled with the ANN is promising to be an alternative to non-destructively classifying the internal quality of fruits.

We report on highly pure green upconversion (UC) photoluminescence in a Ho3+/Yb3+/Li+ co-doped ZnGa2O4 phosphor prepared by the solid-state reaction method for the first time. The crystallite size,...

The ever-mounting drilling operations in the petroleum industry has been accompanied by a tremendous amount of wasted drilling fluid, Polycyclic Aromatic Hydrocarbons (PAHs) in which pose a huge th...

Triboluminescence (TL) refers to the luminescence phenomenon at the material surface under the action of pressure or shear. This fascinating phenomenon can directly convert mechanical energy into light emission without the need for other auxiliary components; therefore, it attracts more and more researchers to conduct research in different wavelength ranges, such as X-ray, ultraviolet, visible light, and terahertz. However, there have been few reports on the study of the near-infrared (NIR) range, which is very important in the integrity of the triboluminescence research. In this research, we found that NIR light with a wavelength ranging from 800 to 1000 nm was generated by friction between solid metals and a quartz crystal. Analysis of the cross section of the quartz disk after friction revealed that the TL phenomenon had a strong relationship with the doping of metal grains into the silica. Density functional theory (DFT) and X-ray photoelectron spectroscopy were also conducted to further identify the results. We infer that such light emission arises from the implantation of metal grains into the surface of the quartz, which forms a metal-insulator junction with amorphous silica. Moreover, electron transition between the metal and the insulator, followed by a transition at the center of the defects, causes near-infrared light emission. Our research reveals the infrared luminescence behavior from a different perspective, the transfer of materials, and perhaps deepens the understanding of the near-infrared emission mechanism.

Hybrid micro/nanomotors with multiple distinct propulsion modes are expected to improve their motion ability in complex body fluids. Herein, we report a multi-stimuli propelled Janus lipase-modified dendritic silica/carbon@Pt (DMS/C@Pt) nanomotor with built-in engines for hybrid propulsions of H2O2, light, and enzyme. The enhanced motion of the DMS/C@Pt nanomotor is achieved under the stimulus of H2O2 that produces an oxygen concentration gradient derived from the asymmetric catalysis of Pt nanoparticles. Irradiated with near-infrared (NIR) light, the uneven photothermal effect of the carbon part propels this nanomotor by self-thermophoresis. Besides, lipase is efficiently loaded into the dendritic pores, which decomposes triglyceride on the silica part and induces self-diffusiophoretic propulsion. These multiple propulsions shed light on the rational integration of various functional building blocks into one micro/nanomotor for complex tasks in biomedical applications.

Near-infrared (NIR) light-emitting devices with organic semiconductors have great potential for applications in bio-imaging, telecommunication, night-vision displays, and chemical sensing. Light-emitting electrochemical cells (LECs) have demonstrated the advantages of a simple and solution-processable device architecture, low operation bias, and compatibility with air-stable cathode metals. To obtain pure and efficient NIR EL with an emission peak close to or exceeding 800 nm, we fabricated NIR LECs based on the excimer formation of the red cationic iridium complex (NIRex). NIR LECs that employ neat films of complex NIRex exhibit NIR EL centered at 860 nm. To further improve device efficiency, complex RED is incorporated to disperse complex NIRex to reduce concentration quenching. Increasing the incorporation amount of complex RED (0 to 60 wt%) to disperse the guest complex NIRex leads to blue-shifted EL (ELmax = 860 to 744 nm), an enhanced output power (143 to 637 μW cm−2) and an improved EQE (0.26 to 0.82%). The output power and EQE obtained in this work are rather high among the reported NIR LECs exhibiting EL emission peaks exceeding 750 nm. Therefore, NIR LECs based on excimer formation in thin films of cationic iridium complexes have great potential as efficient NIR light sources.

Recently, the rapid development of biomaterials has induced great interest in the precisely targeted treatment of bone-related diseases, including bone cancers, infections, and inflammation. Realizing noninvasive therapeutic effects, as well as improving bone tissue regeneration, is essential for the success of bone‑related disease therapies. In recent years, researchers have focused on the development of stimuli-responsive strategies to treat bone-related diseases and to realize bone regeneration. Among the various external stimuli for targeted therapy, near infrared (NIR) light has attracted considerable interests due to its high tissue penetration capacity, minimal damage toward normal tissues, and easy remote control properties. The main objective of this systematic review was to reveal the current applications of NIR light-assisted phototherapy for bone-related disease treatment and bone tissue regeneration. Database collection was completed by June 1, 2020, and a total of 81 relevant studies were finally included. We outlined the various therapeutic applications of photothermal, photodynamic and photobiomodulation effects under NIR light irradiation for bone‑related disease treatment and bone regeneration, based on the retrieved literatures. In addition, the advantages and promising applications of NIR light-responsive drug delivery systems for spatiotemporal-controlled therapy were summarized. These findings have revealed that NIR light-assisted phototherapy plays an important role in bone-related disease treatment and bone tissue regeneration, with significant promise for further biomedical and clinical applications.

Transition-metal chalcogenide compounds with facile preparation and multifunctional elements act as ideal photothermal agents for cancer theranostics. This work synthesizes Cu7.2S4/5MoS2 composite nanoflowers and investigates the crystal growth mechanism to optimize the synthesis strategy and obtain excellent photothermal therapy agents. Cu7.2S4/5MoS2 exhibits a high photothermal conversion efficiency of 58.7% and acts as a theranostic nanoplatform and demonstrated an effective photothermal–chemodynamic–photodynamic synergetic therapeutic effect in both in vitro and in vivo tests. Moreover, Cu7.2S4/5MoS2 shows strong photoacoustic signal amplitudes and computed tomographic contrast enhancement in vivo. These results suggest a potential application of Cu7.2S4/5MoS2 composite nanoflowers as photo/H2O2-responsive therapeutic agents against tumors.

Harnessing cost-efficient printable semiconductor materials as near-infrared (NIR) emitters in light-emitting diodes (LEDs) is extremely attractive for sensing and diagnostics, telecommunications, and biomedical sciences. However, the most efficient NIR LEDs suitable for printable electronics rely on emissive materials containing precious transition metal ions (such as platinum), which have triggered concerns about their poor biocompatibility and sustainability. Here, we review and highlight the latest progress in NIR LEDs based on non-toxic and low-cost functional materials suitable for solution-processing deposition. Different approaches to achieve NIR emission from organic and hybrid materials are discussed, with particular focus on fluorescent and exciplex-forming host-guest systems, thermally activated delayed fluorescent molecules, aggregation-induced emission fluorophores, as well as lead-free perovskites. Alternative strategies leveraging photonic microcavity effects and surface plasmon resonances to enhance the emission of such materials in the NIR are also presented. Finally, an outlook for critical challenges and opportunities of non-toxic NIR LEDs is provided., Graphical abstract, Highlights • Telecommunications and biomedical sensors will hugely benefit from the development of non-toxic NIR LEDs. • Both organic and hybrid materials reported remarkable performance in the 700- to 1000-nm range. • Aggregation and the energy gap law represent the toughest hurdles to overcome for efficient NIR emission in organic materials. • Leveraging AIE, TADF, and hybrid materials have proven successful in improving efficiencies.

Narrowing the size of near-infrared (NIR) spectrometers has gained substantial interest among researchers in both scientific and nonscientific communities due to the inherent usage in the nondestru...

Current photodynamic therapy faces two major challenges, which are the limited tissue penetration of excitation light and poor tumor selectivity of the photosensitizer. To address these issues, in ...

On a global scale, bacterial infection has become a huge threat to human health. Taking into consideration the increasing drug-resistance bacteria, it is urgent to develop novel nonantibiotics stra...

The effective delivery of light energy from the light source to the subject is essential for an increase of therapeutic usefulness in the photobiomodulation therapy. Here, we demonstrate the application-specific near-infrared (NIR) LED therapy system applicable to the mouse for brain repair. The proposed NIR LED therapy system especially employ the curved-shape NIR LED module and the LED dimmer for optimal transfer of the light energy to the mouse brain. The therapeutic effects are evaluated in mice with chronic cerebral hypoperfusion by the positron emission tomographic scans. In the near future, we would like to quantitatively validate the therapeutic effect of our proposed NIR LED therapy system on mice with brain injury and apply it to a human brain.

Aim: To develop a H2O2/near-infrared (NIR) laser light-responsive nanoplatform (manganese-doped Prussian blue@polypyrrole [MnPB@PPy]) for synergistic chemo/photothermal cancer theranostics. Materials & methods: Doxorubicin (DOX) was loaded onto the surface of polypyrrole shells. The in vitro and in vivo MRI performance and anticancer effects of these nanoparticles (NPs) were evaluated. Results: The MnPB@PPy NPs could not only generate heat under NIR laser irradiation for cancer photothermal therapy but also act as an excellent MRI contrast agent. The loaded DOX could be triggered to release by both NIR light and H2O2 to enhance synergistic therapeutic efficacy. The antitumor effects were confirmed by in vitro cellular cytotoxicity assays and in vivo treatment in a xenograft tumor model. Conclusion: The designed H2O2/NIR light-responsive MnPB@PPy-DOX NPs hold great potential for future biomedical applications.

In this work, near-infrared light (NIRL)-responsively controlled-release herbicide particles (NCHPs) were fabricated using biochar, attapulgite (ATP), NH4HCO3, ethylcellulose (EC), silicon oil (SO)...

We fabricated polarized near-infrared (NIR) emitting devices using with the oriented films of a low-band-gap-polymer PTB7 (poly{4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']tithiophene-2,6-diyl-alt...

Hydrogel microfibers with inhomogenous structure can achieve some complex motions such as bending, folding and twisting. So it can be applied to soft actuators, soft robots and micropumps. In this paper, continuous bilayer hydrogel fibers in which one layer is calcium alginate hydrogel and the other is linear poly(N-isopropylacrylamide) (PNIPAM)/calcium alginate/graphene oxide (GO) semi-interpenetrating hydrogel were prepared based on microfluidic spinning method. The results show that the bilayer hydrogel fibers have particular porous internal structures of semi-IPN hydrogels and the pore size becomes smaller with the increase of GO content. Besides, the bilayer hydrogel fibers can bend response to the temperature and near-infrared (NIR) light. The diameter of the hydrogel fibers can be tuned by changing the flow rate of spinning fluid and the take-up velocity of winding device.

Conventional chemotherapeutic drugs cause systemic side effects due to nonspecific interactions with healthy tissues, which significantly hinders their tolerability and efficacy. Herein, we develop...

Junhui Shi,1 Zhengyan Zhao,2 Zongjun Liu,3 Ruozheng Wu,1 You Wang11School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, People’s Republic of China; 2State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, People’s Republic of China; 3School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, People’s Republic of ChinaBackground: The design of novel nanoparticles with higher therapeutic efficacy and lower side effects, is still difficult but encouraging in cancer therapy. Specifically, for upconversion nanoparticles (UCNP)-based drug release, a high intensity of NIR light (1.4∼5.0 W/cm2,) above the maximum permissible exposure (0.33 W/cm2, for 980 nm) is commonly used and severely limits its practical application.Methods: The highly emissive UCNP is first synthesized and then coated with mesoporous silica (MS) shell (UCMS). Next, the surface of UCMS is modified with the thioether (-S-BP) linker, leading to UCMS-S-BP nanoparticles. Finally, after the drug doxorubicin (Dox) is loaded into the pore channels of UCMS, the pore openings are blocked by the β-cyclodextrin (β-CD) gatekeeper through the association with the -S-BP linker (UCMS(Dox)-S-BP@β-CD).Results: Upon 980 nm NIR light irradiation with an ultralow intensity of 0.30 W/cm,2 it is found that the loaded Dox can be released through the cleavage of thioether linkers triggering dissociation ofβ-CD gatekeepers. The in vitro results exhibited significantly therapeutic efficacy with 85.2% of HeLa cells killed in this study.Conclusions: An ultralow-intensity NIR light triggered on-demand drug release system has been developed by employing highly emissive UCNP and photocleavable linker with low bond dissociation energy to avoid the potential photodamage on healthy neighbor cells.Keywords: drug release, ultralow intensity, density functional theory, near infrared light, upconversion nanoparticles

In vivo noninvasively manipulating biological functions by the mediation of biosafe near infrared (NIR) light is becoming increasingly popular. For these applications, upconversion rare-earth nanomaterial holds great promise as a novel photonic element, and has been widely adopted in optogenetics. In this article, an upconversion optogenetic nanosystem that was promised to achieve autophagy up-regulation with spatiotemporal precision was designed. The implantable, wireless, recyclable, less-invasive and biocompatible system worked via two separated parts: blue light-receptor optogenetics-autophagy upregulation plasmids, for protein import; upconversion rods-encapsulated flexible capsule (UCRs-capsule), for converting tissue-penetrative NIR light into local visible blue light. Results validated that this system could achieve up-regulation of autophagy in vitro (in both HeLa and 293T cell lines) and remotely penetrate tissue (∼3.5 mm) in vivo. Since autophagy serves at a central position in intracellular signalling pathways, which is correlative with diverse pathologies, we expect that this method could establish an upconversion material-based autophagy up-regulation strategy for fundamental and clinical applications.

Application of carbon nanomaterials to near-infrared light-mediated phototherapy has attracted great interest. However, their practical use in biological systems is severely limited by their poor water dispersibility, inevitable adsorption of plasma proteins, and their single therapeutic function. Herein, we prepared a phycocyanin (PC)-functionalized single-walled carbon nanohorns (PC@SWNHs) hybrid, where PC is used to preform a protein corona around the SWNHs through non-covalent interface interactions. In the PC@SWNHs, the preformed PC corona effectively improves the water dispersibility of the SWNHs and protects them from plasma protein adsorption. In addition, the excellent photodynamic activity of PC overcomes the inability of SWNHs to generate reactive oxygen species. The SWNHs not only give the hybrid a photothermal therapy (PTT) function, but they also enhance the photostability of PC. These characteristics of the PC@SWNHs are confirmed by in vitro and in vivo experiments, where synergistic photodynamic therapy (PDT)/PTT growth inhibition of tumors is achieved. The PC@SWNHs also act as a photoacoustic/thermal imaging agent to visualize the in vivo treatment process. Hence, this work not only paves the way to use the complementarity between SWNHs and proteins for multifunctional cancer theranostics, but it also allows for a better understanding of bio–nano interface interactions between them.

A cyclopentadithiophene (DTC)-bridged acceptor–donor–acceptor (A–D–A) backboned small molecule acceptor (SMA), namely IDTC-4Cl, was designed and synthesized. In combination with strong electron-withdrawing (5,6-dichloro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene)dimalononitrile as a terminal group, IDTC-4Cl exhibits a near-infrared light absorption with an edge over 900 nm. Using PBDB-T as the polymer donor, the IDTC-4Cl based device gives a PCE of 9.51% with a Voc of 0.822 V, FF of 60.2% and Jsc of 19.14 mA cm−2. Upon introduction of PC71BM as the third component, the ternary OSCs show an enhanced PCE of 10.41% with a much improved FF of 65.6%, which exemplifies the potential of utilizing a DTC unit to construct an SMA for high-performance organic photovoltaics.

A near-infrared light triggered photothermal H2S-release platform was developed using a combination of photothermal nanoparticles and thermo-labile precursors, and was exploited for synchronous photothermal stimulation and gas release to suppress cell viability. Polyethyleneimine-dithiocarbamate as a H2S donor was assembled on reduced graphene oxide (rGO) nanosheets by electrostatic adsorption. In the nanocomposites, rGO nanosheets converted near-infrared light into thermal energy and activated the H2S donor to produce H2S. Synchronous photothermal stimulation and H2S gas release resulted in effective killing of cancer cells. This work presents an effective method that suppresses the growth of tumour cells and leads to an improved anti-cell proliferation outcome. Near-infrared light-triggered photothermal stimulation, in combination with H2S gas generation, may offer an effective strategy to further develop a cancer synergistic treatment platform.

Upconversion nanoparticles (UCNPs) represent a class of optical nanomaterials that can convert low-energy excitation photons to high-energy fluorescence emissions. On the basis of UCNPs, heterostructured UCNPs, consisting of UCNPs and other functional counterparts (metals, semiconductors, polymers, etc.), present an intriguing system in which the physicochemical properties are largely influenced by the entire assembled particle and also by the morphology, dimension, and composition of each individual component. As multicomponent nanomaterials, heterostructured UCNPs can overcome challenges associated with a single component and exhibit bifunctional or multifunctional properties, which can further expand their applications in bioimaging, biodetection, and phototherapy. In this review, we provide a summary of recent achievements in the field of heterostructured UCNPs in the aspects of construction strategies, synthetic approaches, and types of heterostructured UCNPs. This review also summarizes the trends in biomedical applications of heterostructured UCNPs and discusses the challenges and potential solutions in this field.

In this work, we developed a digital microfluidic platform based on a shape memory micropillar array responsive to near-infrared light, and the droplets were programmatically manipulated through light-induced micropillar deformation. The micropillar array was constructed on the surface of a poly(ethylene-vinyl acetate) copolymer, a shape memory polymer sensitive to near-infrared light. Before droplet manipulation, the micropillar array was kept temporarily tilted by heating and pressing. Under the irradiation of a near-infrared laser, the micropillar array achieved the transition from the temporary shape to the original shape. Temperature gradient and micropillar deformation caused by near-infrared light irradiation produce the driving force for droplet movement. The movement of the laser mounted on an electronically controlled displacement platform was controlled by a computer to achieve the programmed control of the droplets. Moreover, we demonstrated light-manipulated droplet movement and fusion, and achieved ascorbic acid detection using this digital microfluidic platform. In particular, the micropillar array chip is able to manipulate droplets in a wide range of 0.1 μL to 10 μL. The proposed digital microfluidic platform will broaden the application of digital microfluidic technology in analytical chemistry and biomedicine.

An on-demand drug delivery nanoplatform based on mesoporous silica (mSiO2) coated upconversion nanoparticles (UCNP@mSiO2) with a novel near-infrared (NIR) light-triggered hydrophobic-to-hydrophilic switch nanovalve was fabricated. The surface of UCNP@mSiO2 was first immobilized with hydrophobic 2-diazo-1,2-naphthoquinones (DNQ) guest molecules. After doxorubicin hydrochloride (DOX, a universal anticancer drug) was loaded into channels of mSiO2 shell, β-cyclodextrin (β-CD) host molecules with a hydrophobic cavity were added as gatekeepers to cap DNQ stalk molecules via hydrophobic affinity, which may play a role in the OFF state of the nanovalve to prevent the drug from being released. Upon 980 nm light irradiation, a NIR light-triggered hydrophobic-to-hydrophilic switch, that transformed the hydrophobic guest DNQ into hydrophilic guest 3-indenecarboxylic acid (ICA), took place so that the capped β-CD gatekeepers dissociated due to repulsion between β-CD host (hydrophobic) and ICA guest (hydrophilic), activating the ON state of the nanovalves to release drug. The in vitro studies prove that the nanoplatform enables on-demand drug release to efficiently kill HeLa cell upon NIR light regulation. The in vivo experiment results further confirm that the nanoplatform with such fabricated nanovalves is able to inhibit tumor growth in mice. The designed nanovalves based on the novel NIR light-triggered hydrophobic-to-hydrophilic switch strategy therefore may shed new light on future development of on-demand cancer therapy.

Early diagnosis and efficient therapy are very important for cancer management. Among the various intelligent delivery systems, near-infrared (NIR) light-triggered polymeric nanomicelles (PNMs) have emerged as a promising approach for imaging and photoactive delivery. This platform can be used for spatially and temporally controlled remote release of therapeutic payload molecules under NIR light irradiation. This review discusses the design and characteristics of PNMs as well as their recent application in imaging, drug delivery, and theranostics in photothermal and photodynamic therapy. The challenges and potential of PNMs in biomedical applications are also highlighted.

Glioblastoma (GBM) is a very aggressive primary malignant brain tumor and finding effective therapies is a pharmaceutical challenge and an unmet medical need. Photothermal therapy may be a promising strategy for the treatment of GBM, as it allows the destruction of the tumor using heat as a non-chemical treatment for disease bypassing the GBM heterogeneity limitations, conventional drug resistance mechanisms and side effects on peripheral healthy tissues. However, its development is hampered by the distinctive features of this tumor. Photoabsorbing agents such as nanoparticles need to reach the tumor site at therapeutic concentrations, crossing the blood-brain barrier upon systemic administration. Subsequently, a near infrared light irradiating the head must cross multiple barriers to reach the tumor site without causing any local damage. Its power intensity needs to be within the safety limit and its penetration depth should be sufficient to induce deep and localized hyperthermia and achieve tumor destruction. To properly monitor the therapy, imaging techniques that can accurately measure the increase in temperature within the brain must be used. In this review, we report and discuss recent advances in nanoparticle-mediated plasmonic photothermal therapy for GBM treatment and discuss the preclinical challenges commonly faced by researchers to develop and test such systems.

In this study, Li-based blue- and green-emitting core@shell (C@S) upconversion nanophosphors (UCNPs) and NaGdF4-based red-emitting C@S UCNPs were synthesized, and IR-808 dyes were conjugated with the C@S UCNPs to enhance upconversion (UC) luminescence. The surface of the as-synthesized C@S UCNPs, which was originally capped with oleic acid, was modified with BF4&minus, to conjugate the IR-808 dye having a carboxyl functional group to the surface of the UCNPs. After the conjugation with IR-808 dyes, absorbance of the UCNPs was significantly increased. As a result, dye-sensitized blue (B)-, green (G)-, and red (R)-emitting UCNPs exhibited 87-fold, 10.8-fold, and 110-fold enhanced UC luminescence compared with B-, G-, and R-emitting Nd3+-doped C@S UCNPs under 800 nm near-infrared (NIR) light excitation, respectively. Consequently, dye-sensitized UCNPs exhibiting strong UC luminescence under 800 nm NIR light excitation have high applicability in a variety of biological applications.

Photodynamic therapy (PDT), a clinically approved cancer treatment strategy, features non-invasiveness, few side-effects, high spatial resolution, etc. The advancement of PDT has been significantly restricted by the penetration depth of the excitation light. Herein, an effective fluorogen, TBD, with aggregation-induced emission characteristics (AIEgen) and high reactive-oxygen-species (ROS) generation efficiency was reported and integrated with a near infrared (NIR) light excitable upconversion nanoparticle (UCNP) to construct NIR light excitable UCNP@TBD nanocomposites. The formed nanocomposite has excellent photostability, good biocompatibility, and efficient ROS generation under NIR light excitation via Forster resonance energy transfer (FRET), enabling NIR light excited PDT. Moreover, the proposed NIR light excited PDT can break the impasse between the penetration depth and excitation volume in conventional PDT, effectively improving the anticancer therapeutic outcome. In vitro cancer cell ablation and in vivo tumor growth inhibition validated that the proposed UCNP@TBD nanocomposite is a promising NIR light excitable PDT agent with great potential for future translational research.

Photothermal therapy is an efficient cancer treatment method. The development of nanoagents with high biocompatibility and a near-infrared (NIR) photoabsorption band is a prerequisite to the success of this method. However, the therapeutic efficiency of photothermal therapy is rather limited because most nanoagents have a low photothermal conversion efficiency. In this study, we aimed to develop CuFeS2 nanoassemblies with an excellent photothermal effect using the liquid-solid-solution method. The CuFeS2 nanoassemblies we developed are composed of ultrasmall CuFeS2 nanoparticles with an average size of 5 nm, which have strong NIR photoabsorption. Under NIR laser illumination at 808 nm at the output power intensity of 1.0 W cm–2, the CuFeS2 nanoassemblies could rapidly convert NIR light into heat, achieving a high photothermal conversion efficiency of 46.8%. When K7M2 cells were incubated with the CuFeS2 nanoassemblies and then exposed to irradiation, their viability decreased progressively as the concentration of the CuFeS2 nanoassemblies increased. Furthermore, a concentration of 40 ppm of CuFeS2 nanoassemblies was lethal to the cells. Importantly, after an intratumoral injection of 40 ppm of CuFeS2 nanoassemblies, the tumor showed a high contrast in the thermal image after laser irradiation, and tumor cells with condensed nuclei and a loss of cell morphology could be thermally ablated. Therefore, the CuFeS2 nanoassemblies we synthesized have a high biocompatibility and robust photothermal effect and can, thus, be utilized as a novel and efficient photothermal agent for tumor therapy.