Achieving Effective Multimodal Imaging with Rare-Earth Ion-Doped CaF2 Nanoparticles

Dual-Mode Nanoprobes Based on Lanthanide Doped Fluoride Nanoparticles Functionalized by Aryl Diazonium Salts for Fluorescence and SERS Bioimaging

The design of dual-mode fluorescence and Raman tags stimulates a growing interest in biomedical imaging and sensing applications as they offer the possibility to synergistically combine the versatility and velocity of fluorescence imaging with the specificity of Raman spectroscopy. Although lanthanide-doped fluoride nanoparticles (NPs) are among the most studied fluorescent nanoprobes, their use for the development of bimodal fluorescent-Raman probes has never been reported yet, to the best of the authors knowledge, probably due to the difficulty to functionalize them with Raman reporter groups. This gap is filled herein by proposing a fast and straightforward approach based on aryl diazonium salt chemistry to functionalize Eu3+ or Tb3+ doped CaF2 and LaF3 NPs by Raman scatters. The resulting surface-enhanced Raman spectroscopy (SERS)-encoded lanthanide-doped fluoride NPs retain their fluorescence labeling capacity and display efficient SERS activity for cell bioimaging. The potential of this new generation of bimodal nanoprobes is assessed through cell viability assays and intracellular fluorescence and Raman imaging, opening up unprecedented opportunities for biomedical applications.

Preparation of rare earth-doped nano-fluorescent materials in the second near-infrared region and their application in biological imaging

Second near-infrared (NIR-II) fluorescence imaging (FLI) has gained widespread interest in the biomedical field because of its advantages of high sensitivity and high penetration depth. In particular, rare earth-doped nanoprobes (RENPs) have shown completely different physical and chemical properties from macroscopic substances owing to their unique size and structure. This paper reviews the synthesis methods and types of RENPs for NIR-II imaging, focusing on new methods to enhance the luminous intensity of RENPs and multi-band imaging and multi-mode imaging of RENPs in biological applications. This review also presents an overview of the challenges and future development prospects based on RENPs in NIR-II regional bioimaging.

Correction: Yu et al. Achieving Effective Multimodal Imaging with Rare-Earth Ion-Doped CaF2 Nanoparticles. Pharmaceutics 2022, 14, 840

There was an error in the original publication [...].

Metal ions as effectual tools for cancer with traditional Chinese medicine

Malignant tumor has become a major threat affecting human health, and is one of the main causes of human death. Recent studies have shown that many traditional Chinese medicines (TCM) have good anti-tumor activity, which may improve the therapeutic effect of routine treatment and quality of life with lower toxicity. However, the efficacy of TCM alone for the treatment of tumors is limited. Metal ions are essential substances for maintaining normal physiological activities. This article summarized the multiple mechanisms in which metal ions are involved in the prevention and treatment of tumors in TCM.

Recent Metal Nanotheranostics for Cancer Diagnosis and Therapy: A Review

In recent years, there has been an increasing interest in using nanoparticles in the medical sciences. Today, metal nanoparticles have many applications in medicine for tumor visualization, drug delivery, and early diagnosis, with different modalities such as X-ray imaging, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), etc., and treatment with radiation. This paper reviews recent findings of recent metal nanotheranostics in medical imaging and therapy. The study offers some critical insights into using different types of metal nanoparticles in medicine for cancer detection and treatment purposes. The data of this review study were gathered from multiple scientific citation websites such as Google Scholar, PubMed, Scopus, and Web of Science up through the end of January 2023. In the literature, many metal nanoparticles are used for medical applications. However, due to their high abundance, low price, and high performance for visualization and treatment, nanoparticles such as gold, bismuth, tungsten, tantalum, ytterbium, gadolinium, silver, iron, platinum, and lead have been investigated in this review study. This paper has highlighted the importance of gold, gadolinium, and iron-based metal nanoparticles in different forms for tumor visualization and treatment in medical applications due to their ease of functionalization, low toxicity, and superior biocompatibility.

Novel Nanoparticle-Based Treatment and Imaging Modalities

Over the last twenty years, nanomaterials have been widely used in cancer research [...].

Rare-Earth-Metal (Nd3+, Ce3+ and Gd3+)-Doped CaF2: Nanoparticles for Multimodal Imaging in Biomedical Applications

Here, we describe the synthesis of a novel type of rare-earth-doped nanoparticles (NPs) for multimodal imaging, by combining the rare-earth elements Ce, Gd and Nd in a crystalline host lattice consisting of CaF2 (CaF2: Ce, Gd, Nd). CaF2: Ce, Gd, Nd NPs are small (15-20 nm), of uniform shape and size distribution, and show good biocompatibility and low immunogenicity in vitro. In addition, CaF2: Ce, Gd, Nd NPs possess excellent optical properties. CaF2: Ce, Gd, Nd NPs produce downconversion emissions in the second near-infrared window (NIR-II, 1000-1700 nm) under 808 nm excitation, with a strong emission peak at 1056 nm. Excitation in the first near- infrared window (NIR-I, 700-900 nm) has the advantage of deeper tissue penetration power and reduced autofluorescence, compared to visible light. Thus, CaF2: Ce, Gd, Nd NPs are ideally suited for in vivo fluorescence imaging. In addition, the presence of Gd3+ makes the NPs intrinsically monitorable by magnetic resonance imaging (MRI). Moreover, next to fluorescence and MR imaging, our results show that CaF2: Ce, Gd, Nd NPs can be used as imaging probes for photoacoustic imaging (PAI) in vitro. Therefore, due to their biocompatibility and suitability as multimodal imaging probes, CaF2: Ce, Gd, Nd NPs exhibit great potential as a traceable imaging agent in biomedical applications.

Recent Progresses in NIR-II Luminescent Bio/Chemo Sensors Based on Lanthanide Nanocrystals

Fluorescent bio/chemosensors are widely used in the field of biological research and medical diagnosis, with the advantages of non-invasiveness, high sensitivity, and good selectivity. In particular, luminescent bio/chemosensors, based on lanthanide nanocrystals (LnNCs) with a second near-infrared (NIR-II) emission, have attracted much attention, owing to greater penetration depth, aside from the merits of narrow emission band, abundant emission lines, and long lifetimes. In this review, NIR-II LnNCs-based bio/chemo sensors are summarized from the perspectives of the mechanisms of NIR-II luminescence, synthesis method of LnNCs, strategy of luminescence enhancement, sensing mechanism, and targeted bio/chemo category. Finally, the problems that exist in present LnNCs-based bio/chemosensors are discussed, and the future development trend is prospected.