Supramolecular Valves Functionalized Rattle-Structured UCNPs@hm-SiO2 Nanoparticles with Controlled Drug Release Triggered by Quintuple Stimuli and Dual-Modality Imaging Functions: A Potential Theranostic Nanomedicine

Quantitative Fluorescent Lateral Flow Strip Sensor for Myocardial Infarction Using Purity-Color Upconversion Nanoparticles

Acute myocardial infarction is a serious cardiovascular disease and poses significant risks to human health. Its early diagnosis and real-time detection are of great importance. Herein, we design a low-cost device that has a high sensitivity of cTnT and cTnI detection. Dual-color upconversion nanoparticles (UCNPs) are prepared as probes, which not only have high-purity red upconversion luminescence (UCL) under 980 or 808 nm excitation but also achieve good temperature sensing. Temperature-dependent multicolor emission excitation is obtained, and the color turns from white to orange and red with increasing temperature. In particular, the maximum SR and SA values based on nonthermally coupled levels are 4.76% K-1 and 8.6% K-1, which are higher than those based on thermally coupled levels. With the UCNPs-based lateral flow strip (LFS), the specific detection of cTnI and cTnT antigens in samples is achieved with a detection limit of 0.001 ng/mL, which is 1 order of magnitude lower than that of their clinical cutoff. The UCNPs-LFS device has a low-cost laser diode and a simplified laser and permits a mobile-phone camera to collect the results, which has an important influence on the field of biomarker sensing.

Remotely Activated DNA Probe System for the Detection and Imaging of Dual miRNAs

Cancers remain the leading cause of mortality worldwide. It is crucial to detect cancer at an early stage for improving survival rates. Biomarkers have precise implications for cancer progression. Here, we built a straightforward DNA probe system that could be activated by near-infrared light to detect dual miRNAs with a high specificity. This probe is built on the basis of upconversion nanoparticles, which could emit ultraviolet light and activate DNA probes adsorbed on the outer layer. The DNA probe system is remotely controlled through manipulation of the near-infrared (NIR) light, enabling simultaneous detection of dual miRNAs. The DNA nanosystem could be effectively endocytosed by cancer cells and reflect expression levels of dual miRNAs. Overall, this study demonstrates a promising remote-controlled DNA nanoplatform for the simultaneous detection of dual miRNAs, which has tremendous potential for precise cancer diagnostics and therapies.

NIR light, pH, and redox-triple responsive nanogels for controlled release

Herein we report a novel spiropyran (SP)-based organic-inorganic composite nanogel (NG), which was prepared using upconverting nanoparticles, spiropyran, acrylic acid and N,N'-bis(acryloyl)cystamine (BAC) compounds under emulsion polymerisation. Compared with other polymer nanoparticles, the crosslinked multi-stimulus responsive nanogels can adjust the release rate by altering more of the parameters and this can meet the needs of a complex biological environment to control the release of drugs. Doxorubicin hydrochlorides were used as a simulated drug to test the drug loading performance and controllable drug release performance of the composite NGs. Under near-infrared light (NIR) irradiation, an acidic environment or a reducing agent, the delivery of the loaded drugs was by controlled release over 24 hours. Under mild triple stimulation (NIR light, pH 6, and 4 mM reducing agent), the loaded drug could be released more efficiently. The organic-inorganic composite NGs with highly-efficient and controllable release performance for loaded drugs provide many choices for novel stimulus responsive nanocarriers.

Upconversion Nanoparticle-Based Cell Membrane-Coated cRGD Peptide Bioorthogonally Labeled Nanoplatform for Glioblastoma Treatment

Glioblastoma is hard to be eradicated partly because of the obstructive blood-brain barrier (BBB) and the dynamic autophagy activities of glioblastoma. Here, hydroxychloroquine (HDX)-loaded yolk-shell upconversion nanoparticle (UCNP)@Zn0.5Cd0.5S nanoparticle coating with the cyclic Arg-Gly-Asp (cRGD)-grafted glioblastoma cell membrane for near-infrared (NIR)-triggered treatment of glioblastoma is prepared for the first time. UCNPs@Zn0.5Cd0.5S (abbreviated as YSN, yolk-shell nanoparticle) under NIR radiation will generate reactive oxygen species for imposing cytotoxicity. HDX, the only available autophagy inhibitor in clinical studies, can enhance cytotoxicity by preventing damaged organelles from being recycled. The cRGD-decorated cell membrane allowed the HDX-loaded nanoparticles to efficiently bypass the BBB and specifically target glioblastoma cells. Exceptional treatment efficacy of the NIR-triggered chemotherapy and photodynamic therapy was achieved in U87 cells and in the mouse glioblastoma model as well. Our results provided proof-of-concept evidence that HDX@YSN@CCM@cRGD could overcome the delivery barriers and achieve targeted treatment of glioblastoma.

Upconversion Nanostructures Applied in Theranostic Systems

Upconversion (UC) nanostructures, which can upconvert near-infrared (NIR) light with low energy to visible or UV light with higher energy, are investigated for theranostic applications. The surface of lanthanide (Ln)-doped UC nanostructures can be modified with different functional groups and bioconjugated with biomolecules for therapeutic systems. On the other hand, organic molecular-based UC nanostructures, by using the triplet-triplet annihilation (TTA) UC mechanism, have high UC quantum yields and do not require high excitation power. In this review, the major UC mechanisms in different nanostructures have been introduced, including the Ln-doped UC mechanism and the TTA UC mechanism. The design and fabrication of Ln-doped UC nanostructures and TTA UC-based UC nanostructures for theranostic applications have been reviewed and discussed. In addition, the current progress in the application of UC nanostructures for diagnosis and therapy has been summarized, including tumor-targeted bioimaging and chemotherapy, image-guided diagnosis and phototherapy, NIR-triggered controlled drug releasing and bioimaging. We also provide insight into the development of emerging UC nanostructures in the field of theranostics.

Nanogels loading curcumin in situ through microemulsion photopolymerization for enhancement of antitumor effects

Drug-loaded nanogels for cancer treatment can limit the free diffusion and distribution of drug molecules in the whole body to reduce undesirable side effects and improve the drug absorption efficiency of the tumor. In this study, curcumin as a model drug was encapsulated into nanogels in situ through microemulsion photopolymerization at 532 nm. Nanogels loaded with curcumin (NG-C) displayed a diameter of around 150 nm with good stability and a low polydispersity index of around 0.1. NG-C had a drug-loading capacity of 8.96 ± 1.16 wt%. The cumulative release of curcumin from NG-C was around 25%, 34% and 55% within 90 h in pH 7.4, 6.8 and 5.0 PBS buffer, respectively. NG-C presented prominent cytotoxicity toward Hep G2 and HeLa cancer cells in vitro. Moreover, NG-C exhibited much a stronger inhibition of tumor growth, necrosis, apoptosis, and the suppression of proliferation compared with curcumin on Hep G2 tumor-bearing nude mice.

Protein-Gated Upconversion Nanoparticle-Embedded Mesoporous Silica Nanovehicles via Diselenide Linkages for Drug Release Tracking in Real Time and Tumor Chemotherapy

Two novel stimuli-responsive drug delivery systems (DDSs) were successfully created from bovine serum albumin- or myoglobin-gated upconversion nanoparticle-embedded mesoporous silica nanovehicles (UCNP@mSiO2) via diselenide (Se-Se)-containing linkages. More importantly, multiple roles of each scaffold of the nanovehicles were achieved. The controlled release of the encapsulated drug doxorubicin (DOX) within the mesopores was activated by triple stimuli (acidic pH, glutathione, or H2O2) of tumor microenvironments, owing to the conformation/surface charge changes in proteins or the reductive/oxidative cleavages of the Se-Se bonds. Upon release of DOX, the Förster resonance energy transfer between the UCNP cores and encapsulated DOX was eliminated, resulting in an increase in ratiometric upconversion luminescence for DOX release tracking in real time. The two protein-gated DDSs showed some differences in the drug release performances, relevant to structures and properties of the protein nanogates. The introduction of the Se-Se linkages not only increased the versatility of reductive/oxidative cleavages but also showed less cytotoxicity to all cell lines. The DOX-loaded protein-gated nanovehicles showed the inhibitory effect on tumor growth in tumor-bearing mice and negligible damage/toxicity to the normal tissues. The constructed nanovehicles in a spatiotemporally controlled manner have fascinating prospects in targeted drug delivery for cancer chemotherapy.

Ultrasmall Ternary FePtMn Nanocrystals with Acidity-Triggered Dual-Ions Release and Hypoxia Relief for Multimodal Synergistic Chemodynamic/Photodynamic/Photothermal Cancer Therapy

Multimodal imaging-guided synergistic anticancer strategies have attracted increasing attention for efficient diagnosis and therapy of cancer. Herein, a multifunctional nanotheranostic agent FePtMn-Ce6/FA (FPMCF NPs) is constructed by covalently anchoring photosensitizer chlorin e6 (Ce6) and targeting molecule folic acid (FA) on ultrasmall homogeneous ternary FePtMn nanocrystals. Response to tumor microenvironment (TME), FPMCF NPs can release Fe²⁺ to catalyze H₂ O₂ into •OH by Fenton reaction and simultaneously catalyze hydrogen peroxide (H₂ O₂ ) into O₂ to overcome the tumor hypoxia barrier. Released O₂ is further catalyzed into ¹ O₂ under 660 nm laser irradiation with Ce6. Thus, the FPMCF NPs exhibit superior dual-ROS oxidization capability including ferroptosis chemodynamic oxidization and ¹ O₂ -based photodynamic oxidization. Interestingly, FPMCF NPs reveal strong photothermal conversion efficiency exposed to an 808 nm laser, which can assist dual-ROS oxidization to suppress solid tumor remarkably. Additionally, Mn²⁺ can be released from FPMCF NPs to enhance longitudinal relaxivity (T₁ -weighted magnetic resonance (MR) imaging) and Fe-synergistic transverse relaxivity (T₂ -weighted MR imaging), which is convenient for diagnosis of solid tumors. Meanwhile, the fluorescent/photothermal (FL/PT) imaging function of FPMCF NPs can also accurately monitor tumor location. Therefore, FPMCF NPs with multimodal MR/FL/PT imaging-guided synergistic chemodynamic/photodynamic/photothermal cancer therapy capability have potential bioapplication in bionanomedicine field.