Nm Near-infrared Research Articles

MoO3-x nanosheets-based platform for single NIR laser induced efficient PDT/PTT of cancer

Traditional combination therapy of photodynamic therapy (PDT) and photothermal therapy (PTT) is limited in the field of clinical cancer therapy due to activation by light with separate wavelengths, insufficient O2 supply, antioxidant ability of glutathione (GSH) in tumor cell, and low penetration depth of light. Here, a multifunctional nanoplatform composed of MoO3-x nanosheets, Ag nanocubes, and MnO2 nanoparticles was developed to overcome these drawbacks. For this nanoplatform, hyperthermia and reactive oxygen species (ROS) were simultaneously generated under single 808 nm near-infrared (NIR) light irradiation. Once this nanoplatform accumulated in the tumor region, GSH was depleted by MnO2 and intracellular H2O2 was catalyzed by MnO2 to produce O2 to relieve hypoxia. Ultrasound (US) imaging confirmed in-situ O2 generation. Magnetic resonance (MR) imaging, photoacoustic (PA) imaging, and fluorescence imaging were used to monitor in vivo biodistribution of nanomaterials. This provides a paradigm to rationally design a single NIR laser induced multimodal imaging-guided efficient PDT/PTT cancer strategy.

A facile photothermometric sensor of acid phosphatase based on CoOOH nanozymes-mediated 3,3′,5,5′-tetramethylbenzidine photothermal system

Nanozymes-catalyzed 3,3′,5,5′-tetramethylbenzidine (TMB) reaction systems have been extensively used for fabricating colorimetric sensors, but they still require advanced instruments like color analysis software or ultraviolet spectrophotometers to achieve accurate quantitative analysis. Herein, we explored an alternative strategy to convert a color readout to a temperature readout of a CoOOH nanoflakes-TMB colorimetric reaction system, and successfully fabricated a simple and facile photothermometric sensor of acid phosphatase (ACP) by using a common thermometer as the reader. It mainly performed based on the strong photothermal effect of the oxidation product (TMBox) of TMB upon an 808 nm near-infrared (NIR) laser irradiation, which showed a close relationship with the ACP content with a lower limit of detection (LOD) of 0.037 mU/mL for photothermometric ACP determination. This photothermometric method was proved to be suitable for not only sensing ACP but also screening its inhibitor in human serum, and providing a simple, rapid, convenient, low cost, and portable organic chromogenic substrate-based sensing platform.

An intratumoral injectable nanozyme hydrogel for hypoxia-resistant thermoradiotherapy

Hypoxia in local tumors leads to the failure or resistance of radiotherapy (RT) and high-dose RT will cause systemic reactions and local radiation damage. As a non-chemotherapeutic intervention, photothermal therapy (PTT) can remove tumor tissues through thermal ablation as well as effectively improve the microenvironment of hypoxic cells. Therefore, the combined use of PTT and RT (thermoradiotherapy) has urgently become an efficient treatment. In this work, by encapsulating prussian blue (PB) nanoparticles in agarose hydrogel, we developed an injectable hybrid light-controlled hydrogel system as a PB reservoir and release controller (PRC) which can realize single injection and multiple treatments in vivo. Under the irradiation of 808 nm near-infrared (NIR) laser, PB nanoparticles convert laser energy into heat energy, causing degradation of agarose hydrogel and the release of PB nanoparticles. Due to the excellent photothermal properties of PB, photothermal treatment in the NIR Biological Windows can greatly enhance the sensitivity of tumor cells to RT. Meanwhile, PB nanoparticles can also be a nanozyme to drive the decomposition of endogenous hydrogen peroxide (H2O2), and then generate oxygen (O2) to improve the tumor hypoxic microenvironment, achieving the further enhancement of the radiation sensitivity. Notably, this study is the first design to utilize hydrogel for thermoradiotherapy. Both in vitro and in vivo experiments, the PRC demonstrated excellent effects of PTT-RT, good stability and biocompatibility, indicating our nanoplatform promote the development of anti-cancer combination thermoradiotherapy with greater clinical significance.

Near-Infrared Light and Upconversion Nanoparticle Defined Nitric Oxide-Based Osteoporosis Targeting Therapy.

Osteoporosis is one of the most common diseases affecting bone metabolism. Nitric oxide (NO), an endogenous gas molecule involved in osteogenesis, can effectively promote the proliferation and differentiation of osteoblasts. Although exogenous NO can reverse osteoporosis to a certain extent, the transitory half-life and short diffusion radius of NO severely limit its application. In this work, a gas generation nanoplatform of NO with bone targeting property (UCPA) is developed based on the upconversion nanoparticles (UCNPs) that can convert 808 nm near-infrared (NIR) light into UV/blue light, and further stimulate the NO donor (BNN) to release NO. With an adjustment of the output power of the 808 nm NIR, the amount of released NO can be precisely controlled. Both in vitro and in vivo experiments demonstrate the favorable affinity of UCPA to bone due to the modification of alendronate; thus, it can directly release NO in bone and reverse osteoporosis. In addition, the cellular uptake of nanocomposites and intracellular NO release can be observed in preosteoblasts, thereby promoting their differentiation efficiently.

Shape effects of gold nanoparticles in photothermal cancer therapy

Gold Nanoparticles based Plasmonic Photothermal Therapy (PPTT) has recently been extensively studied in cancer treatment, based on the local hyperthermia induced by their plasmonic photothermal effect on cancer cells or tissues. Although AuNPs with various morphologies have shown photothermal conversion capabilities, their performance in photothermal therapy is still in debate. To reveal the AuNPs with the most promising PPTT performance, three commonly established gold nanostructures: gold nanospheres (AuNSs), gold nanorods (AuNRs), gold nanostars (AuNSTs), were synthesized in this study with identical mPEG-SH surface modification. The corresponding PTT performance and antitumor effect were evaluated and compared. It was found that all AuNPs can convert 808 nm Near-Infrared (NIR) laser light energy into heat through the Localized Surface Plasmon Resonance effect, and AuNSTs showed the highest photothermal conversion efficiency. In vitro cell experiments demonstrated that all PEGylated AuNPs had low cytotoxicity and AuNSTs were the most capable ones in inducing local hyperthermia under an identical condition of 10 min 300 mW/cm2 NIR light irradiation. Therefore, with the same surface modification, AuNSTs should be the most promising agent for PTT therapy among their counterparts.

Immunostimulatory photochemotherapeutic nanocapsule for enhanced colon cancer treatment

Abstract Immunotherapy has made great progress in recent years while most cancer patients cannot benefit from it. Photochemotherapy combination strategy holds great promise for developing novel immunotherapy for the patients bearing immunosuppressive tumors such as colon cancer. In this research, a novel core/shell-structured polydopamine (PDA)-based nanoplatform is constructed to load two Food and Drug Administration (FDA)-approved cytotoxic drugs, i.e. immunostimulatory doxorubicin (Dox) and immunomodulatory curcumin (Cur) to achieve immunostimulatory photochemotherapy of primary colon tumors upon 808 nm near infrared (NIR) irradiation (1 W/cm2 for 5 min) and subsequent prevention of rechallenged distant colon tumors. The experimental data have shown that PDA-mediated photothermal therapy (PTT) synergized two therapeutic drugs in inducing colon cancer cell death and very efficiently inhibited the primary tumor growth (by ∼92%) at very low doses of therapeutics (0.25, 5, and 30 mg/kg of Dox, Cur, and PDA, respectively). More significantly, the combined photochemotherapy promoted strong adaptive antitumor immune responses and successfully prevented tumorigenesis in the setting of tumor rechallenge model. Our research has thus demonstrated the promising efficacy of this photochemotherapeutic nanoformulation for colon cancer treatment and provided a way to improve immunostimulatory effects of conventional chemotherapeutic drugs.

Towards Efficient Luminescent Solar Energy Concentrator Using Cuprorivaite Infrared Phosphor (CaCuSi4O10)-Effect of Dispersing Method on Photoluminescence Intensity.

Cuprorivaite, also known as Egyptian blue (EB), CaCuSi4O10, has been utilized as an important blue pigment for thousands of years. It shows a 430–800 nm broad excitation band and an intense 910–920 nm near-infrared (NIR) emission peak at room temperature. The application that motivates the current research is for luminescent solar concentrator (LSC) usage. Current technology for this purpose relies on high near-infrared reflectance. This article addresses the investigation of the relationship between dispersing methods and photoluminescence (PL) intensity. Mechanical grinding methods investigated in the study were: horizontal bead mill, exfoliation and three-roll mill. The initial aim of the study was to verify if the proposed methods do not damage PL. To the surprise of the authors, three-roll mill treatment enhanced PL by nearly 50% without altering the morphology of the powder. An X-ray diffraction study suggested slight alterations in the crystal lattice.

Upconverted Metal-Organic Framework Janus Architecture for Near-Infrared and Ultrasound Co-Enhanced High Performance Tumor Therapy.

Strict conditions such as hypoxia, overexpression of glutathione (GSH), and high concentration of hydrogen peroxide (H2O2) in the tumor microenvironment (TME) limit the therapeutic effects of reactive oxygen species (ROS) for photodynamic therapy (PDT), chemodynamic therapy (CDT), and sonodynamic therapy (SDT). Here we fabricated a biocatalytic Janus nanocomposite (denoted as UPFB) for ultrasound (US) driven SDT and 808 nm near-infrared (NIR) light mediated PDT by combining core-shell-shell upconversion nanoparticles (UCNPs, NaYF4:20%Yb,1%Tm@NaYF4:10%Yb@NaNdF4) and a ferric zirconium porphyrin metal organic framework [PCN-224(Fe)]. Our design not only substantially overcomes the inefficient PDT effect arising from the inadequate Förster resonance energy transfer (FRET) process from UCNPs (donor) to MOFs (acceptor) with only NIR laser irradiation, but also promotes the ROS generation via GSH depletion and oxygen supply contributed by Fe3+ ions coordinated in UPFB as a catalase-like nanozyme. Additionally, the converted Fe2+ from the foregoing process can achieve CDT performance under acidic conditions, such as lysosomes. Meanwhile, UPFB linked with biotin exhibits a good targeting ability to rapidly accumulate in the tumor region, verified by fluorescence imaging and T2-weighted magnetic resonance imaging (MRI). In a word, it is believed that the synthesis and antitumor detection of UPFB heterostructures render them suitable for application in cancer therapeutics.

Design of a thermally stable and highly active SERS optical sensor for the ultrasensitive detection of dye molecules at high-temperature

Surface enhanced Raman spectroscopy (SERS) with both enhanced activity and pronounced thermal stability is very suitable for ultra-sensitive monitoring of thermally assisted chemical bonding/fragmentation reactions in important industrial catalysis. Herein, we report an appealing thermally stable SERS active sensor based on the construction of multiple-branched Au/Ag nanodendrites (NDs). The obtained Au/Ag NDs with tremendous elongated branches and enormous antennas exhibit a much higher SERS activity for dye detection under 785 nm near infrared (NIR) laser irradiation, as compared to as-prepared other reference samples. Meanwhile, the corresponding unique intermetallic synergy can effectively suppress the oxidation of chemically active Ag in a hot environment. It is important that more than 90% SERS activity at room temperature (∼25 ℃) can be well maintained at high temperature (∼170 ℃) within 30 min continuous tests. Thus, it holds great potential for the in-situ SERS monitoring of high-temperature catalytic reactions in the future.

Detection of Burmese pythons in the near-infrared versus visible band.

Human task performance studies are commonly used for detecting and identifying potential military threats. In this work, these principles are applied to detection of an environmental threat: the invasive Burmese python. A qualitative detection of Burmese pythons with a visible light camera and an 850 nm near-infrared (NIR) camera was performed in natural Florida backgrounds. The results showed that the difference in reflectivity between the pythons and native foliage was much greater in NIR, effectively circumventing the python's natural camouflage in the visible band. In this work, a comparison of detection performance in the selected near-infrared band versus the visible band was conducted. Images of foliage backgrounds with and without a python were taken in each band in daylight and at night with illumination. Intensities of these images were then calibrated and prepared for a human perception test. Participants were tasked with detecting pythons, and the human perception data was used to compare performance between the bands. The results show that the enhanced contrast in the NIR enabled participants to detect pythons at 20% longer ranges than the use of visible imagery.

Water-soluble PANI:PSS designed for spontaneous non-disruptive membrane penetration and direct intracellular photothermal damage on bacteria

The major challenge in the field of antibacterial agents is to overcome the low-permeability of bacteria cell membranes that protects the cells against diverse drugs. In this work, water-soluble polyaniline (PANI)-poly (p-styrenesulfonic acid) (PSS) (PANI:PSS) is found to spontaneously penetrate bacteria cellular membranes in a non-disruptive way, leaving no evidence of membrane poration/disturbance or cell death, thus avoiding side effects caused by cationic ammonia groups in traditional ammonia-containing antibacterial agents. For aqueous synthesis, which is important for biocompatibility, the polymer is synthesized via an enzyme-mimetic route relying on the catalysis of a nanozyme. Owing to its fluorescent properties, the localization of as-prepared PANI:PSS is determined by the confocal microscope, and the results confirm its rapid entry into bacteria. Under 808 nm near-infrared (NIR) irradiation, the internalized PANI:PSS generates local hyperthermia and destroys bacteria highly efficiently from inside the cells due to its excellent photothermal effects. Staphylococcus aureus (S. aureus), Methicillin-resistantStaphylococcus aureus (MRSA) and Escherichia coli (E. coli) could be effectively eliminated as well as the corresponding bacterial biofilms. Results of in vivo antibacterial experiments demonstrate excellent antibacterial activities of the water-soluble PANI:PSS without side effects. Therefore, the prepared water-soluble polymer in this study has great potential in the treatment of various bacterial infections.

Highly doped NaErF4-based nanocrystals for multi-tasking application

How to engineer single nanocrystal to achieve multiple functions is still a huge challenge. In this work, a novel highly doped rare earth nanocrystal NaErF4@NaGdF4@NaDyF4 (Er@Gd@Dy) was designed and fabricated, which exhibits various performances by itself, including the longitudinal (T1) and transverse relaxation time (T2) double-mode magnetic resonance imaging (MRI), upconversion luminescence and down-shifting luminescence. Upon irradiation of 808 nm near-infrared (NIR) light, the upconverted red light can indirectly activate the photosensitizer Ce6 conjugated on the surface of nanocrystals for photodynamic therapy (PDT). In vivo experiments demonstrate that the nanomaterials can eradicate notably primary tumors without obvious systematic toxicity. In addition, the longitudinal and transverse relaxation rates of Er@Gd@Dy are 24.83 and 319.86 (mmol/L)−1/s, respectively, which are superior to those of the nanocrystals reported previously. Simultaneously, the nanocrystals have the ability to generate NIR-II light located at 1530 nm, favorable in bioimaging in deeper tissues. As a consequence, this new nanoplatform will advance the improvement of multimodal imaging guided tumor diagnosis and treatment.

Rapid and Local Self-Healing Ability of Polyurethane Nanocomposites Using Photothermal Polydopamine-Coated Graphene Oxide Triggered by Near-Infrared Laser.

In this study, we report the self-healing ability of polyurethane (PU) nanocomposites based on the photothermal effect of polydopamine-coated graphene oxide (PDA–rGO). Polydopamine (PDA) was coated on the graphene oxide (GO) surface, while simultaneously reducing GO by the oxidation of dopamine hydrochloride in an alkaline aqueous solution. The PDA–rGO was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, and scanning electron microscopy–energy-dispersive X-ray analysis. PDA–rGO/PU nanocomposites with nanofiller contents of 0.1, 0.5 and 1 wt% were prepared by ex situ mixing method. The photothermal effect of the PDA–rGO in the PU matrix was investigated at 0.1 W/cm2 using an 808 nm near-infrared (NIR) laser. The photothermal properties of the PDA–rGO/PU nanocomposites were superior to those of the GO/PU nanocomposites, owing to an increase in the local surface plasmon resonance effect by coating with PDA. Subsequently, the self-healing efficiency was confirmed by recovering the tensile stress of the damaged nanocomposites using the thermal energy generated by the NIR laser.

880 nm NIR-Triggered Organic Small Molecular-Based Nanoparticles for Photothermal Therapy of Tumor.

Photothermal therapy (PTT) has received constant attention as an efficient cancer therapy method due to locally selective treatment, which is not affected by the tumor microenvironment. In this study, a novel 880 nm near-infrared (NIR) laser-triggered photothermal agent (PTA), 3TT-IC-4Cl, was used for PTT of a tumor in deep tissue. Folic acid (FA) conjugated amphiphilic block copolymer (folic acid-polyethylene glycol-poly (β-benzyl-L-aspartate)10, FA-PEG-PBLA10) was employed to encapsulate 3TT-IC-4Cl by nano-precipitation to form stable nanoparticles (TNPs), and TNPs exhibit excellent photothermal stability and photothermal conversion efficiency. Furthermore, the in vitro results showed TNPs display excellent biocompatibility and significant phototoxicity. These results suggest that 880 nm triggered TNPs have great potential as effective PTAs for photothermal therapy of tumors in deep tissue.

Engineering Eu3+-incorporated MoS2 nanoflowers toward efficient photothermal/photodynamic combination therapy of breast cancer

Two-dimensional MoS2 (2D-MoS2) and its nanocomposites have been extensively studied in cancer therapy research since their prominent surface area and NIR absorption ability. In this work, Eu3+-incorporated MoS2 (MoS2:Eu3+) nanoflowers with enhanced photothermal conversion efficiency (PCE) were successfully developed by a one-step bottom-up hydrothermal method. Under 808 nm near-infrared (NIR) laser irradiation, the photothermal agents MoS2:5%Eu3+ nanoflowers have a PCE at ~ 49.05%, which is 1.75 times higher than the pristine MoS2. MoS2:5%Eu3+ as efficient photosensitizers also promote generation of cytotoxic reactive oxygen species (ROS) under 808 nm laser irradiation, thus achieving photodynamic therapy (PDT) for cancers at the same time. Enhanced in vitro breast cancer therapy through the combination of photothermal therapy (PTT) and PDT is clearly proved by using the MoS2:Eu3+ nanosheet as a multifunctional nanoprobe. The unique MoS2:Eu3+ works as a promising nanoprobe for PDT/PTT cancer therapies, and also provides a novel strategy for PCE improvement of the 2D-MoS2.

An Exceptional Broad-Spectrum Nanobiocide for Multimodal and Synergistic Inactivation of Drug-Resistant Bacteria

An Exceptional Broad-Spectrum Nanobiocide for Multimodal and Synergistic Inactivation of Drug-Resistant Bacteria

Photothermal-controlled sustainable degradation of protective coating modified Mg alloy using near-infrared light

Controlling the corrosion rate is critical for practical applications of Mg-based alloys. In this work, we constructed a protective coating of hybrid polycaprolactone (H-PCL)/indocyanine green (ICG) on AZ31 Mg alloy, whose degradation rate was controlled by 808-nm near-infrared (NIR) light irradiation. The corrosion behaviors of H-PCL/ICG coated Mg alloys were systematically investigated by potentiodynamic polarization tests, electrochemical impedance spectroscopy (EIS) and hydrogen evolution experiments. The results disclosed that the H-PCL/ICG composite coating could effectively protect Mg alloy from corroding without NIR light irradiation. In contrast, under 808-nm NIR light irradiation, the corrosion resistance of this composite coating was decreased significantly, i.e., the corrosion current density (icorr) increased from (8.81 ± 1.068) × 10−8 to (1.22 ± 0.545) × 10−6 A·cm−2. This is because the component of ICG in the coating was excited to produce heat locally, which triggered the glass transition temperature (Tg) of H-PCL in the coating, resulting in the motion of the molecular chain segment. Consequently, the electrolytes penetrated the coating and corroded the Mg substrate. In vitro biological experiment indicated that the synthesized coating exhibited good cytocompatibility. Hence, these findings will provide a new strategy for designing novel photoresponsive coatings to remotely adjust the degradation rate of biodegradable metals for biomedical applications.

Rapid bacteria capturing and killing by AgNPs/N-CD@ZnO hybrids strengthened photo-responsive xerogel for rapid healing of bacteria-infected wounds

Rapid bacteria killing and tissue repair are critical for the fast healing of bacteria-infected wounds, especially under poor sanitation without antibiotics. Herein, we prepared a novel xerogel constructed by thioether as a main chain and embedded by Ag nanoparticles (NPs) and ZnO NPs decorated by N-doped carbon dots (N-CD@ZnO). This hybrid xerogel not only has good mechanical properties without swelling but also has the ability to capture bacteria rapidly by the disulfide group through electrostatic interaction. Under 808 nm near-infrared (NIR) light irradiation for 15 min, this hybrid xerogel killed 99.9% Escherichiacoliand 99.85% Staphylococcus aureus by the synergistic action of released Ag+ and reactive oxygen species (ROS) produced by N-CD@ZnO using up-conversion technology (N-CD reduces the biotoxicity of ZnO and changes its photocatalytic response region from the 368 nm ultraviolet (UV) region to the 808 nm NIR region). In addition, the biotoxicity of Ag+ is limited by the Ag-S covalent bond, which ensures good biocompatibility for the xerogel. Finally, in wound repair experiments in vivo, this xerogel is able to completely repair the wound within 10 days. This work will open up a new avenue for xerogel antibacterial materials.

Using Gd-Enhanced β-NaYF4:Yb,Er Fluorescent Nanorods Coupled to Reduced TiO2 for the NIR-Triggered Photocatalytic Inactivation of Escherichia coli

β-NaYF4:Yb,Er,Gd fluorescent nanorods were successfully coupled to a reduced TiO2 (UCNPs@R-TiO2) nanocomposite and applied to visible-light catalytic sterilization under 980 nm near-infrared (NIR) light illumination. The UCNPs (β-NaYF4:Yb,Er,Gd) absorb the NIR light and emit red and green light. The visible light can be absorbed by the R-TiO2 (Eg = 2.8 eV) for the photocatalytic reaction. About 98.1% of Escherichia coli were effectively killed upon 12 min of NIR light irradiation at a minimum inhibitory concentration (MIC) of 40 μg/mL UCNPs@R-TiO2 nanocomposite. The bactericidal properties were further evaluated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis. We found that the high bactericidal activity was due to the synergistic effect between the UCNPs and R-TiO2. Moreover, the UCNPs show excellent upconversion luminance properties, and the introduction of visible-light-absorbed R-TiO2 nanoparticles (2.8 eV) was conducive to the efficient separation and utilization of photogenerated electron-hole pairs.

Fabrication of electrically highly conductive, mechanically strong, and near-infrared responsive phytic acid crosslinked polypyrrole coated Korean paper

Herein, we present a mechanically strong, stable highly conductive Korean traditional paper “Hanji” membrane via the simple coating with the polypyrrole (PPy) and further crosslinked it by phytic acid (PA). The FE-SEM images exhibited the compact network formation upon the crosslinking. PA crosslinked samples exhibited superior thermal stability, tensile properties, and electrical conductivity as compared to the non-PA-containing membrane i.e. PPy@Hanji. Moreover, the PA crosslinked PPy coated Hanji mat exhibited photothermal properties and had shown excellent stability under the irradiation of 808 nm near-infrared (NIR) light. The improved performance of the PA containing membrane was attributed to the effective crosslinking effect of the PPy chains held by the hydrogen bonding with the PA. Thus, this study presents the strategy of the increasing thermal, electrical stability of the conductive polymer-based membranes which can be applied in various research areas such as sensing, energy storage, metal adsorption, and so on.