Orthogonal Near-Infrared-II Imaging Enables Spatially Distinguishing Tissues Based on Lanthanide-Doped Nanoprobes.

Multichannel near-infrared (NIR)-II imaging provides more precise and detailed information for studying complex biological processes. When studying specific biological processes, a separated single signal and multisignals are essential but difficult to obtain by traditional multichannel NIR-II imaging methods. Taking advantage of the unique optical properties of lanthanide ions, especially in atom-like absorbance and emission spectroscopy in the NIR region, in this study, we synthesized two lanthanide-doped nanoprobes, NaYF4:Gd@NaYF4:Nd@NaYF4 (cssNd) and NaYF4:Gd@NaYF4:Er@NaYF4 (cssEr). These two nanoprobes show orthogonal NIR-II emissions (1064 and 1330 nm for cssNd and 1550 nm for cssEr) under 730 and 980 nm excitation, respectively. The feasibility of cssNd and cssEr for multichannel NIR-II imaging was proven in vitro. Under different methods of administering the nanoprobes, in vivo multichannel NIR-II imaging with both the separated single signal and multisignals was successfully performed and could spatially distinguish tissues under two different excitation sources. Our results provide a new method for multichannel NIR-II imaging with separable signals, which is promising for precisely studying complex biological processes precisely.

Orthogonal shortwave infrared emission based on rare earth nanoparticles for interference-free logical codes and bio-imaging.

Shortwave infrared (SWIR) photoluminescence has received intense interest in many fields in recent years thanks to the advantages of its wide wavelength range and high tissue imaging ability and it is invisible to the naked eye. However, achieving orthogonal SWIR emission still remains a challenge. In the present study, synthesized NaErF4@NaLuF4 (Er@Lu) and NaYF4:Nd@NaLuF4 (Y:Nd@Lu) nanoparticles emitted atom-like SWIR emission, and the separation distance between the SWIR emission was beyond 50 nm, which permitted orthogonal SWIR signal acquirement with optical filters. Furthermore, an invisible logical code was designed by manipulating the orthogonal SWIR emission of the lanthanide fluoride nanoparticles, and was further operated by basic logical operations and applied in information encryption and anti-counterfeit fields. In addition, the emission between these two hydrophilic nanoparticles could also be separated in vivo without signal interference and the orthogonal SWIR imaging mode was achieved, which was demonstrated in a bio-imaging experiment in vivo. This demonstration extended the orthogonal SWIR emission capacity by controlling the orthogonal emission, opening new opportunities in the fields of data security, disease diagnosis and non-interference label in vivo.

Rationally designed pure-inorganic upconversion nanoprobes for ultra-highly selective hydrogen sulfide imaging and elimination in vivo.

Lung injury is a hydrogen sulfide (H2S)-associated complication with high mortality in acute pancreatitis (AP) cases. Herein, we used Prussian Blue (PB) as a H2S-responsive acceptor to develop a novel pure-inorganic upconversion nanoprobe for detecting and eliminating H2S, which can be used for diagnosing AP and alleviating lung injury. Upconversion nanoprobes with 5 nm PB shells were optimized to achieve outstanding in vitro H2S detection capacity (linear range: 0-150 µM, LOD: 50 nM), which met the in vivo serum H2S range, and thus were feasible for imaging H2S in vivo. More importantly, when combined with the traditional H2S synthetase inhibitor dl-PAG, the nanoprobes also served as a therapeutic agent that synergistically alleviated lung injury. As PB is an FDA-approved drug, our work proposes a potential clinical modality for the early diagnosis of AP, which will decrease lung injury-induced mortality and increase the survival rates of AP cases.

Biocompatible Heat-Shock Protein Inhibitor-Delivered Flowerlike Short-Wave Infrared Nanoprobe for Mild Temperature-Driven Highly Efficient Tumor Ablation.

Multifunctional nanomaterials for dual-mode imaging guided cancer therapy are highly desirable in clinical applications. Herein, a flowerlike NiS2-coated NaLuF4:Nd (Lu:Nd@NiS2) nanoparticle was synthesized as a novel therapeutic agent for short-wave infrared light imaging and magnetic resonance imaging to guide photothermal therapy (PTT). The material was then loaded with phenolic epigallocatechin 3-gallate (EGCG), which is a natural heat-shock protein 90 (HSP90) inhibitor. Upon near infrared irradiation, EGCG was released from the Lu:Nd@NiS2-EGCG, which bound HSP90 and reduced cell tolerance to heat, resulting in a better therapeutic effect at the same elevated temperature. Therefore, with minimal side effects and remarkable antitumor efficacy in vivo, Lu:Nd@NiS2-EGCG appeared to be a promising photothermal agent for enhanced PTT.

Green synthesis of ultra-small VOx nanodots for acidic-activated HSP60 inhibition and therapeutic enhancement.

Using metal oxide semiconductor nanomaterials for synergistic cancer treatment has recently attracted the attention of numerous researchers. Herein, oxygen-defective vanadium oxide nanodots (VOx NDs) with ultra-small size and great dispersibility were synthesized via a novel user-friendly method, and then doxorubicin was loaded onto the VOx NDs surfaces. The VOx NDs had great photothermal conversion efficiency and stability. Doxorubicin-loaded VOx NDs can simultaneously serve as therapeutic agent and tumor microenvironment-activable HSP60 inhibitor, resulting in improved efficacy of photothermal therapy and released active doxorubicin for chemotherapy. Finally, we show that synergistic treatment achieved significant therapeutic effects in mice. These results provided a promising strategy for developing novel methods of synthesizing metal oxide semiconductors for enhanced synergistic cancer treatment.

Rationally designed upconversion nanoprobe for simultaneous highly sensitive ratiometric detection of fluoride ions and fluorosis theranostics.

For many years, fluorosis has been known as a worldwide disease which seriously diminishes quality of life through skeletal embrittlement and hepatic damage. Aiming to develop novel drugs for simultaneous fluorosis diagnosis and therapy, in this work we explore the feasibility of a novel pyrogallic acid-titanium(iv) complex-modified upconversion nanoprobe (UCNP-PA-Ti) for F- capture and real-time quantification. Utilizing the strong interaction between Ti4+ and F-, the modified PA-Ti decomposes in F--containing solution, which not only weakens the FRET but results in upconversion luminescence (UCL) recovery. Both in vitro and in vivo experiments demonstrate a highly sensitive F- UCL response and therapeutic efficiency, which was promising for successful UCL image monitoring and the therapeutic process. Long blood circulation time and low toxicity ensured their safe application for fluorosis theranostics. Our work provides a new possibility for F- concentration detection within fluorosis therapeutic periods and encourages the development of novel drugs for fluorosis theranostics.