NIR-II Window Research Articles

Synthesis of multi-branched Au nanocomposites with distinct plasmon resonance in NIR-II window and controlled CRISPR-Cas9 delivery for synergistic gene-photothermal therapy

Clinical implementation of photothermal therapy (PTT) is mainly hampered by limited tissue penetration, undesirable thermal damage to normal tissues, and thermotolerence induced by heat shock proteins (HSPs). To overcome these obstacles, we constructed a novel gene-photothermal synergistic therapeutic nanoplatform composed of a multi-branched Au nanooctopus (AuNO) core and mesoporous polydopamine (mPDA) shell, followed by CRISPR–Cas9 ribonucleoprotein (RNP) loading and then polyethylene glycol-folic acid (PEG-FA) coating. AuNO was simply synthesized by adjusting the ratio of cetyltrimethylammonium chloride (CTAC) and cetyltrimethylammonium bromide (CTAB), which showed significant localized surface plasmon resonances in the NIR-II window, and exhibited an excellent tissue penetration capability and high photothermal conversion efficiency (PCE, 47.68%). Even, the PCE could be further increased to 66.17% by mPDA coating. Furthermore, the sequential modification of AuNO@mPDA using RNP and PEG-FA can down-regulate HSP90α expression at tumor sites, enhance apoptosis and reduce the heat resistance of cancer cells. The synergistic effect of enhanced photothermal capacity and reduced thermoresistance addressed the multiple limitations of PTT, and presented excellent in vitro and in vivo antitumor efficacy, having great potential for the clinical application of PTT.

Biomimetic manganese-based theranostic nanoplatform for cancer multimodal imaging and twofold immunotherapy.

The limited clinical response and serious side effect have been challenging in cancer immunotherapy resulting from immunosuppressive tumor microenvironment (TME) and inferior drug targeting. Herein, an active targeting TME nanoplatform capable of revising the immunosuppressive TME microenvironment is designed. Briefly, gold nanorods (GNRs) are covered with silica dioxide (SiO2) and then coated manganese dioxide (MnO2) to obtain GNRs@SiO2@MnO2 (GSM). Myeloid-derived suppressor cells (MDSCs) membrane is further camouflaged on the surface of GSM to obtain GNRs@SiO2@MnO2@MDSCs (GSMM). In this system, GSMM inherits active targeting TME capacity of MDSCs. The localized surface plasmon resonance of GNRs is developed in near-infrared II window by MnO2 layer coating, realizing NIR-II window photothermal imaging and photoacoustic imaging of GSMM. Based on the release of Mn2+ in acidic TME, GSMM can be also used for magnetic resonance imaging. In cancer cells, Mn2+ catalyzes H2O2 into ·OH for (chemodynamic therapy) CDT leading to activate cGAS-STING, but also directly acts on STING inducing secretion of type I interferons, pro-inflammatory cytokines and chemokines. Additionally, photothermal therapy and CDT-mediated immunogenic cell death of tumor cells can further enhance anti-tumor immunity via exposure of CRT, HMGB1 and ATP. In summary, our nanoplatform realizes multimodal cancer imaging and dual immunotherapy.

Electronic and Near-Infrared-II Optical Properties of I-Doped Monolayer MoTe2: A First-Principles Study.

Near-infrared-II (NIR-II, 1000–1700 nm) fluorescence imaging is widely used for in vivo biological imaging. With the unique electronic structures and capability of band-gap engineering, two-dimensional (2D) materials can be potential candidates for NIR-II imaging. Herein, a theoretical investigation of the electronic structure and optical properties of iodine (I)-doped monolayer MoTe2 systems with different doping concentrations is carried out through simulations to explore their NIR optical properties. The results suggest that the emergence of impurity levels due to I doping effectively reduces the bandwidth of I-doped monolayer MoTe2 systems, and the bandwidth decreases with the increase in the I doping concentration. Although the I and Mo atoms possess clear covalent-bonding features according to the charge density difference, impurity levels induced by the strong hybridization between the I 5p and Mo 4d orbitals cross the Fermi level, making the doped systems exhibit metallic behavior. In addition, with the increase in the I doping concentration, the energy required for electron transition from valence bands to impurity levels gradually decreases, which can be linked to the enhancement of the optical absorption in the red-shifted NIR-II region. Meanwhile, with a higher I doping concentration, the emission spectra, which are the product of the absorption spectra and quasi-Fermi distributions for electrons and holes, can be enhanced in the NIR-II window.

Theranostic Nanomedicine in the NIR-II Window: Classification, Fabrication, and Biomedical Applications.

ADVERTISEMENT RETURN TO ISSUEHighlightNEXTTheranostic Nanomedicine in the NIR-II Window: Classification, Fabrication, and Biomedical ApplicationsWei Tao*Wei TaoCenter for Nanomedicine and Department of Anesthesiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States*Email: [email protected]More by Wei Tao and Omid C. Farokhzad*Omid C. FarokhzadCenter for Nanomedicine and Department of Anesthesiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United StatesSeer, Inc., Redwood City, California 94065, United States*Email: [email protected]More by Omid C. FarokhzadCite this: Chem. Rev. 2022, 122, 6, 5405–5407Publication Date (Web):March 23, 2022Publication History Received1 February 2022Published online23 March 2022Published inissue 23 March 2022https://doi.org/10.1021/acs.chemrev.2c00089Copyright © Published 2022 by American Chemical SocietyRIGHTS & PERMISSIONSArticle Views2180Altmetric-Citations2LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (2 MB) Get e-AlertsSUBJECTS:Biological imaging,Carbon nanotubes,Fluorescence imaging,Molecular imaging,Optical imaging Get e-Alerts

Synchronously boosting type-I photodynamic and photothermal efficacies via molecular manipulation for pancreatic cancer theranostics in the NIR-II window

In view of the fact that pancreatic cancer, called as the king of cancer, is one of the most lethal malignancies, exploring effective technologies for pancreatic cancer diagnosis and therapy remains an appealing yet significantly challenging task. Phototheranostics has recently received considerable attention by virtue of its various distinctive advantages. However, the limited penetration depth, strong oxygen-dependence and high heat shock protein-inhibition of conventional phototheranostic materials severely hamper their overall theranostic efficacy, especially for deep-seated hypoxia tumors, such as pancreatic tumor. In this study, an aggregation-induced emission (AIE)-featured photosensitizer, namely DCTBT, synchronously sharing NIR-II fluorescence imaging (FLI), diminished oxygen-dependent type-I photodynamic therapy (PDT) and high-efficiency photothermal therapy (PTT) functions was subtly constructed by molecular engineering. With the aid of an EGFR-targeting-peptide-modified amphiphilic polymer, the as-prepared DCTBT-loaded liposomes is capable of effectively accumulating at and visualizing pancreatic tumor, as well as significantly suppressing the tumor growth on both subcutaneous and orthotopic PANC-1 tumor mice models. This study thus brings useful insights into designing the next generation of cancer theranostic agents for potential clinical applications.

In Vivo High-Resolution Bioimaging of Bone Marrow and Fracture Diagnosis Using Lanthanide Nanoprobes with 1525 nm Emission.

Bones play vital roles in human health. Noninvasive visualization of the full extent of bones is highly demanded to evaluate many bone-related diseases. Herein, we report poly (acrylic acid) (PAA)-modified NaLuF4:Yb/Er/Gd/Ce@NaYF4 nanoparticles (PAA-Er) with second near-infrared emission beyond 1500 nm (also referred as NIR-IIb) for high-resolution bone/bone marrow imaging and bone fracture diagnosis. The NIR-IIb optical-guided bone marrow imaging presents a high signal to noise ratio, which is superior to that for imaging in the NIR-II window (1000-1400 nm, NIR-IIa). Importantly, we also investigated the size-dependent accumulation of the nanoparticles and the possible accumulation mechanism of the designed PAA-Er nanoprobes in bone marrow. Due to the high affinity capability of the PAA-Er nanoprobes, a highly sensitive NIR-IIb optical-guided bone fracture diagnosis was successfully achieved. This novel technology paves the way to design lanthanide nanoprobes for NIR-IIb optical-guided high-resolution bone marrow imaging and bone-related disease diagnosis.

Case Report: The Second Near-Infrared Window Indocyanine Green Angiography in Giant Mediastinal Tumor Resection

Giant mediastinal tumors are often accompanied by the abundant blood supply and have an unclear border with adjacent vessels, making surgical resection difficult. Failure to distinguish the complex vessels during the operation often results in vascular injury or hemorrhage, which severely increases the operation time and perioperative risk. At present, surgeons can only determine the vessel's location and course by preoperative imaging and intraoperative exploration in visible light. Therefore, we report a case of a giant anterosuperior mediastinal tumor resection assisted by near-infrared (NIR) indocyanine green (ICG) angiography. Furthermore, we applied the second near-infrared window (NIR-II, 1,000–1,700 nm) to detect the fluorescence signals in the clinic for the first time. The NIR-II window is able to explore deeper tissues in centimeters and obtain higher resolution in millimeters than the traditional first near-infrared window (NIR-I, 700–900 nm). Finally, NIR-II ICG angiography shows the clear location and course of the vessels, which can help surgeons reduce unnecessary blood vessel injury and increase the safety of mediastinal tumor resection.

Marriage of Heterobuckybowls with Triptycene: Molecular Waterwheels for Separating C60 and C70.

Exploration of π-conjugated polycycles, particularly those have π-frameworks spread over the three-dimensional space, is essential in materials science and synthetic chemistry as these chemical entities possess featured optoelectronic properties and supramolecular assembly. Herein, the bowl-shaped trichalcogenasumanenes are fused onto three branches of triptycene through pyrazine units, affording waterwheel-like three-dimensional polycycles 4 a/4 b. Because the three branches on 4 a/4 b are chemically equal, the molecular orbitals of 4 a/4 b show degenerate feature that results in the strong UV-Vis absorbance at steady state. 4 a/4 b exhibit photo-induced charge-separation and subsequent charge-redistribution at transient state, leading to excited state absorption in NIR-II window (1165-1400 nm). 4 a/4 b are excellent fullerene receptors, and they form 1 : 1 host-guest complexes with C60 /C70 as proved by spectroscopic titrations and single crystal structure analysis. Moreover, 4 a/4 b show much stronger affinity toward C70 than C60 . Consequently, 4 a/4 b are able to separate C60 and C70 from their mixture, giving the purity of C60 up to 99.5 %.

Orthogonal Multiplexed NIR-II Imaging with Excitation-Selective Lanthanide-Based Nanoparticles.

Multiplexed imaging in the second near-infrared (NIR-II, 1000-1700 nm) window, with much reduced tissue scattering and autofluorescence background noises, could offer comprehensive information for studying biological processes and accurate diagnosis. A critical requirement for harvesting the full potential of multiplexing is to develop fluorescent probes with emission profiles specifically tuned at distinct excitations toward their target applications. However, the lack of versatile probes with separated signals in this NIR-II window hinders the potential of in vivo multiplexed imaging. In this study, we designed three types of Nd3+-, Ho3+-, and Er3+-based down-shifting nanoparticles (DSNPs) with core-shell structures (csNd, csHo, and csEr). Excitation wavelengths of these nanoparticles were first screened and confirmed at 730, 915, and 655 nm. Under the new excitations, orthogonal three-color emissions in the NIR-II window (1060, 1180, and 1525 nm for csNd, csHo, and csEr, respectively) were efficiently achieved. These excitation-selective DSNPs were then demonstrated to be promising in encrypted anticounterfeiting applications with increased optical codes. By programmed administration of the DSNPs, anatomical rotation imaging can also be successfully performed to differentiate mouse bones, stomach, and blood vessels with high contrast and resolution in a fixed NIR-II channel (>1000 nm) by only switching the excitation wavelengths. This study suggests that the designed NIR-II excitation-selective DSNPs with orthogonal emissions may offer a powerful framework for spatially multiplexed imaging in biological and life sciences.

Precise in Vivo Inflammation Imaging in the NIR-II Window Using 1065 nm Photoacoustic Probe for in Situ Visual Monitoring of Pathological Processes Related to Hepatitis.

The interaction between light and biological tissues in the second near-infrared (NIR-II) window is weak, which can effectively reduce the scattering and absorption of incoming light by biological tissues and enhance the resolution and sensing ability of in vivo photoacoustic (PA) imaging. In particular, tissues that carry blood and water produce the lowest PA background in the wavelength range of 1050 to 1150 nm. However, the development of the NIR-II PA probe for the above window faces great challenges. To tackle this challenge, the reduction-reoxidation of an organic dye was used to develop a PA imaging probe (Hydro-1048) as the first NIR-II PA probe of a hydroxy radical (·OH) for molecular imaging in deep tissue. The ·OH oxidized the C-N single bond in Hydro-1048 to double bonds, which formed Et-1065. This conversion extended the conjugate system of the molecule and shifted the absorption peak from 520 to 1065 nm, which resulted in a strong PA signal after irradiation with a 1065 nm laser. At a detection limit of 0.6 nM, a good linear relationship within the range of 5-1000 nM was obtained for the PA signal intensity versus the concentration of ·OH. The developed NIR-II PA probe can be used for the noninvasive high-resolution imaging of ·OH in deep tissue, and the PA imaging of ·OH can also be used to visually monitor in situ pathological processes related to hepatitis.

Fabrication of semiconducting polymer-blend dots with strong near-infrared fluorescence and afterglow luminescence for bioimaging

Fluorescence imaging at longer wavelength and autofluorescence-free imaging were two main strategies to improve the optical imaging performance of traditional near-infrared (NIR) fluorescence imaging, and the design of corresponding imaging agents were heavily explored recently. Herein, polymer-blend dots (PBdots) with strong fluorescence and afterglow luminescence in both NIR-I (700–900 nm) and NIR-II (900–1700 nm) windows were successfully fabricated by encapsulating two functional semiconducting polymers into one nanoparticle. With efficient intra-particle interactions, the PBdots exhibited an afterglow lifetime of 181 s after 730 nm NIR laser activation, which can be activated in vivo. The obtained PBdots with similar emission intensities in NIR-I and NIR-II regions enable fair comparison between different optical imaging modalities, which provides a clear guidance for the choice of suitable imaging modality for different purpose. As the first imaging agents which integrate NIR-II fluorescence imaging and NIR-I afterglow imaging, the PBdots also provide both high resolution and large signal-to-background ratio for blood vessel, lymph node and tumor imaging in living mice.

Localized Degradation of Neutrophil Extracellular Traps by Photoregulated Enzyme Delivery for Cancer Immunotherapy and Metastasis Suppression.

Extrusion of neutrophil extracellular traps (NETs), a fundamental host innate immune defense against pathogens, has recently been linked to cancer resistance to immunotherapy and distant metastasis. These findings highlight interesting areas of cancer-elicited inflammation and potential therapeutic strategies. Disrupting existing NETs with DNase I has been proved to enhance the therapeutic efficacy of tumor immunotherapy and attenuate metastatic spread. However, systemic biodistribution of DNase I raises safety issues, potentially impairing host defense against infection. Hence, tumor-specific delivery and metastatic niche-targeted effects are attractive options for localized degradation of NETs. We have engineered a nanoplatform with a plasmonic gold blackbody (AuPB) core with broad-spectrum photo activity and a mesoporous polydopamine (mPDA) shell for efficient loading and photoregulated release of DNase I. The on-demand released DNase I triggered by the second near-infrared (NIR-II) light irradiation breaks the "NET-mediated physical barrier", thereby increasing the contact of immune cytotoxic cells with tumor cells in living mice and sensitizing immune checkpoint therapy of primary colorectal cancer (CRC). Moreover, the deposition and light-controlled cargo release from systemically delivered AuPB@mPDA carriers in liver, the most frequent site of CRC metastasis, abolished NET-mediated capture of circulating tumor cells and hence metastatic seeding. Our findings indicate that the localized, light-regulated release of DNase I by photoactive carriers in the NIR-II window represent a translational route for immune-mediated tumor regression and metastasis inhibition.

NIR-II Ratiometric Lanthanide-Dye Hybrid Nanoprobes Doped Bioscaffolds for In Situ Bone Repair Monitoring.

In situ monitoring of tissue regeneration progression is of primary importance to basic medical research and clinical transformation. Despite significant progress in the field of tissue engineering and regenerative medicine, few technologies have been established to in situ inspect the regenerative process. Here, we present an integrated second near-infrared (NIR-II, 1000-1700 nm) window in vivo imaging strategy based on 3D-printed bioactive glass scaffolds doped with NIR-II ratiometric lanthanide-dye hybrid nanoprobes, allowing for in situ monitoring of the early inflammation, angiogenesis, and implant degradation during mouse skull repair. The functional bioactive glass scaffolds contribute to more effective bone regeneration because of their excellent angiogenic and osteogenic activities. The reliability of ratiometric fluorescence imaging, coupled with low autofluoresence in the NIR-II window, facilitates the accuracy of in vivo inflammation detection and high-resolution visualization of neovascularization and implant degradation in deep tissue.

The optical research progress of nanophosphors composed of transition elements in the fourth period of near-infrared windows I and II for deep-tissue theranostics.

Research in the field of nano-optics is advancing by leaps and bounds, among which near-infrared (NIR) light optics have attracted much attention. NIR light has a longer wavelength than visible light, such that it can avoid shielding caused by biological tissues. This advantage has driven its importance and practicality in human treatment applications and has attracted significant attention from researchers in academia and industry. In the broad spectrum of infrared light wavelengths, the most noticeable ones are the NIR biological window I of 700-900 nm and window II of 1000-1700 nm. Luminescent materials can effectively cover the NIR biological window with different doping strategies. These doped elements are mostly transition elements with multielectron orbitals. Several nanomaterials based on narrow-spectrum lanthanides have been developed to correspond to biological applications of different wavelengths. However, this review explicitly introduces the absorption and reflection/luminescence interactions between NIR light and biological tissues independently. Unlike the adjustment of the wavelength of the lanthanide series, this review analyzes the NIR optical properties of the fourth-period element ions in transition elements (such as Cr3+ and Ni2+). These elements have a broadband wavelength of NIR light emission and higher quantum efficiency, corresponding to the absorption and emission spectrum and photobiological absorption of different NIR windows for therapeutic diagnosis. Finally, this review lists and explores other broadband NIR phosphors and has tried to discover the possibility of non-invasive precision medicine in the future.

Biomimetic synthesis of 2D ultra-small copper sulfide nanoflakes based on reconfiguration of the keratin secondary structure for cancer theranostics in the NIR-II region.

Two-dimensional transition metal dichalcogenides have attracted widespread attention in cancer theranostics due to their high specific surface area and excellent photothermal conversion properties. However, their dimensions and biodegradability have limited the exploration of the therapeutic properties of transition metal dichalcogenides. Herein, we explore the mechanism of the keratin α-helix-to-random coil transition, as an actuation mechanism for the controllable design and precise synthesis of two-dimension copper sulfide nanoflakes (CuS NFs) with high absorption in the NIR-II window. Upon mixing keratin and Cu2+, the hydrogen bonds that maintain the α-helix are broken by copper ions to form biuret coordination, while the structure of the α-helix is transformed into a random coil, providing a more scalable space for the growth of CuS NFs. The CuS NFs prepared in this way possess the great advantages of outstanding uniformity, size controllability, and biodegradability. Importantly, the CuS NFs in the NIR-II window show an excellent photothermal conversion efficiency (32.9%) and extraordinary photoacoustic signal. This work updates the fabrication of two-dimensional transition metal dichalcogenides and greatly enhances their competitiveness in the area of cancer theranostics in the NIR-II region, and provides significant theoretical and practical opportunities for the development of keratin using biomimetic synthesis.

An active-passive strategy for enhanced synergistic photothermal-ferroptosis therapy in the NIR-I/II biowindows.

Ferroptosis therapy (FT) is an attractive strategy to selectively damage cancer cells through lipid peroxide (LPO) over-accumulation. However, this therapy suffers from poor therapeutic efficacy due to the limited Fenton reaction efficiency and the evolved intrinsic resistance mechanism in the tumor microenvironment (TME). The exploitation of novel ferroptosis inducers is of significance for improving the efficacy of FT. Here, we develop a plate-like Bi2Se3-Fe3O4/Au (BFA) theranostic nanoplatform, which can increase the Fenton reaction rate to enhance FT in an active-passive way. In detail, benefiting from the internal synergistic effect of Fe3O4 NPs and Au NPs and external NIR-mediated hyperthermia, the BFA NPs can boost hydroxyl radical (˙OH) generation to enhance intracellular oxidative stress and further induce ferroptosis by inactivating glutathione peroxidase 4 (GPX4). Furthermore, the BFA NPs show high photothermal conversion efficiency in both the NIR-I and NIR-II windows (66.2% at 808 nm and 58.2% at 1064 nm, respectively); therefore, as a photothermal agent (PTA), they can also ablate cancer cells directly by NIR-triggered photothermal therapy (PTT). Meanwhile, BFA NPs could be used as an efficient diagnostic agent for photoacoustic (PA)/magnetic resonance (MR)/X-ray imaging to guide the synergistic therapy of photothermal-ferroptosis. Therefore, BFA NP-mediated enhanced photothermal-ferroptosis therapy represents a promising strategy for the application of nanomaterials in tumor therapy.

Tumor microenvironment activated nanoenzyme-based agents for enhanced MRI-guided photothermal therapy in the NIR-II window.

We report a nanoenzyme-based photothermal agent, in which the nanoenzyme acts as a peroxidase, prodrug carrier, and MRI contrast agent. The formation of a dimer by the prodrug under the catalysis of the nanoenzyme in the tumor microenvironment causes photothermal conversion activation and MRI signal amplification simultaneously.

PH-Responsive Au@Pd bimetallic core-shell nanorods for enhanced synergistic targeted photothermal-augmented nanocatalytic therapy in the second near-infrared window.

Nanotheranostic agents based on plasmonic nanostructures with their resonance wavelengths located in the second near-infrared window (NIR-II) have gained significant attention in profound tumor photothermal therapy. However, the modulation of localized surface plasmon resonance of gold nanomaterials from the first near-infrared (NIR-I) window to the NIR-II window is still challenging. The structures and compositions of the plasmonic nanomaterials have demonstrated promising characteristics in controlling the optical properties of plasmonic nanostructures. Here, gold nanorod (Au NR) coated with an ultrathin palladium (Pd) shell was developed for tumor-targeted NIR-II photothermal-augmented nanocatalytic therapy through the combination of compositional manipulation and structural evolution strategies. These Au@Pd core-shell hybrid NRs (HNRs) were functionalized with biocompatible chitosan (CS) to acquire lower toxicity and higher stability in physiological systems. Further, Au@Pd-CS HNRs were endowed with an excellent targeting ability by conjugating with folic acid (FA). The as-synthesized Au@Pd-CS-FA HNRs show efficient and complete photothermal ablation of tumor cells upon 1064 nm laser irradiation. The remarkable photothermal conversion efficiency of 69.0% was achieved, which is superior to many reported photothermal agents activated in the NIR-II region. Excitingly, Au@Pd-CS-FA HNRs have peroxidase and catalase activities, simultaneously producing ˙OH for catalytic therapy and O2 for relieving tumor hypoxia and photodynamic therapy. Additionally, in vivo tumor photothermal therapy was carried out, where the biocompatible Au@Pd-CS-FA HNRs penetrate intensely into the tumor cells and consequently show remarkable therapeutic effects. The idea about plasmonic modulation behind the bimetallic core-shell nanostructure in this report can be extended to construct new classes of metal-based nanotheranostic agents with dual-modal combined therapy as an alternative to traditional chemotherapy.

Surfactant-Stripped Semiconducting Polymer Micelles for Tumor Theranostics and Deep Tissue Imaging in the NIR-II Window.

Photoacoustic imaging (PA) in the second near infrared (NIR-II) window presents key advantages for deep tissue imaging owing to reduced light scattering and low background signal from biological structures. Here, a thiadiazoloquinoxaline-based semiconducting polymer (SP) with strong absorption in the NIR-II region is reported. After encapsulation of SP in Pluronic F127 (F127) followed by removal of excess surfactant, a dual functional polymer system named surfactant-stripped semiconductor polymeric micelles (SSS-micelles) are generated with water solubility, storage stability, and high photothermal conversion efficiency, permitting tumor theranostics in a mouse model. SSS-micelles have a wideband absorption in the NIR-II window, allowing for the PA imaging at both 1064 and 1300nm wavelengths. The PA signal of the SSS-micelles can be detected through 6.5cm of chicken breast tissue in vitro. In mice or rats, SSS-micelles can be visualized in bladder and intestine overlaid 5cm (signal to noise ratio, SNR ≈ 17 dB)and 5.8cm (SNR over 10dB) chicken breast tissue, respectively. This work demonstrates the SSS-micelles as a nanoplatform for deep tissue theranostics.

NIR-II Hydrogen-Bonded Organic Frameworks (HOFs) Used for Target-Specific Amyloid-β Photooxygenation in an Alzheimer's Disease Model.

Phototherapy has emerged as a powerful approach for interrupting β-amyloid (Aβ) self-assembly. However, deeper tissue penetration and safer photosensitizers are urgent to be exploited for avoiding damaging nearby normal tissues and improving therapeutic effectiveness. A hydrogen-bonded organic framework (HOF)-based NIR-II photooxygenation catalyst is presented here to settle the abovementioned challenges. By encapsulating the pyridinium hemicyanine dye DSM with a large two-photon absorption (TPA) cross-section in NIR-II window into the porphyrin-based HOF, the resultant DSM@n-HOF-6 exhibits significant two-photon NIR-II-excited Fluorescence Resonance Energy Transfer (FRET) to generate singlet oxygen (1 O2 ) for Aβ oxidation. Further, the target peptides of KLVFFAED (KD8) are covalently grafted on DSM@n-HOF-6 to enhance the blood-brain barrier (BBB) permeability and Aβ selectivity. The HOF-based photooxygenation catalyst shows an outstanding inhibitory effect of Aβ aggregation upon the NIR-II irradiation. Further in vivo studies demonstrate the obvious decrease of craniocerebral Aβ plaques and recovery of memory deficits in triple-transgenic AD (3×Tg-AD) model mice.