DNA-mediated coordinative assembly of upconversion hetero-nanostructures for targeted dual-modality imaging of cancer cells

Synthesis of near-infrared-responsive hexagonal-phase upconversion nanoparticles with controllable shape and luminescence efficiency for theranostic applications

Over the past few decades, photodynamic therapy has been studied as a therapeutic method by generating singlet oxygen through activation of a photosensitizer (PS) to kill cancer cells. However, the light within the activating wavelength range of commercial photosensitizers has a low penetration depth. In this study, we designed multifunctional upconversion nanoparticles (UCNs) that can emit high-energy light by absorbing low-energy near-infrared (NIR) light with excellent tissue permeability through a fluorescence resonance energy transfer procedure. This process can produce reactive oxygen species by activating the PS. We aimed to optimize the thermal decomposition synthesis procedure to produce lanthanide-doped UCNs with a uniform size and improve the photoluminescence efficiency for an NIR-regulated theranostic system. It was confirmed that the morphologies of UCNs can be controlled by varying the reaction time, reaction temperature, and feed molar ratio of the solvent and reactant. The crystalline morphology of the synthesized UCNs showed a thermodynamically stable hexagonal phase. The photoluminescence efficiency of the UCNs also was influenced by size, surface area, crystalline property, and stability in aqueous solution. Furthermore, the surface-modified UCNs with a folic acid-conjugated block copolymer and PS exhibited enhanced singlet oxygen generation and significantly improved aqueous solubility and photoluminescence efficiency.

Self-Assembly of Upconversion Nanoparticles Based Materials and Their Emerging Applications

In the past few decades, significant progress of the conventional upconversion nanoparticles (UCNPs) based nanoplatform has been achieved in many fields, and with the development of nanoscience and nanotechnology, more and more complex situations need a UCNPs based nanoplatform having multifunctions for specific multimodal or multiplexed applications. Through self-assembly, different UCNPs or UCNPs with other materials could be combined together within an entity. It is more like an ideal UCNPs nanoplatform, a unique system with the properties defined by its individual components as well as by the morphology of the composite. Various designs can show their different desired properties depending on the application situation. This review provides a complete summary on the optimization of the synthesis method for the recently designed UCNPs assemblies and summarizes various applications, including dual-modality cell imaging, molecular delivery, detection, and programmed control therapy. The challenges and limitations the UCNPs assembly faces and the potential solutions in this field are also presented.

Recent advances in upconversion nanoparticle-based nanocomposites for gas therapy

Gas therapy has attracted wide attention for the treatment of various diseases. However, a controlled gas release is highly important for biomedical applications. Upconversion nanoparticles (UCNPs) can precisely convert the long wavelength of light to ultraviolet/visible (UV/Vis) light in gas therapy for the controlled gas release owing to their unique upconversion luminescence (UCL) ability. In this review, we mainly summarized the recent progress of UCNP-based nanocomposites in gas therapy. The gases NO, O2, H2, H2S, SO2, and CO play an essential role in the physiological and pathological processes. The UCNP-based gas therapy holds great promise in cancer therapy, bacterial therapy, anti-inflammation, neuromodulation, and so on. Furthermore, the limitations and prospects of UCNP-based nanocomposites for gas therapy are also discussed.

Spherical nucleic acids: Organized nucleotide aggregates as versatile nanomedicine

Spherical nucleic acids (SNAs) are composed of a nanoparticle core and a layer of densely arranged oligonucleotide shells. After the first report of SNA by Mirkin and coworkers in 1996, it has created a significant interest by offering new possibilities in the field of gene and drug delivery. The controlled aggregation of oligonucleotides on the surface of organic/inorganic nanoparticles improves the delivery of genes and nucleic acid-based drugs and alters and regulates the biological profiles of the nanoparticle core within living organisms. Here in this review, we present an overview of the recent progress of SNAs that has speeded up their biomedical application and their potential transition to clinical use. We start with introducing the concept and characteristics of SNAs as drug/gene delivery systems and highlight recent efforts of bioengineering SNA by imaging and treatmenting various diseases. Finally, we discuss potential challenges and opportunities of SNAs, their ongoing clinical trials, and future translation, and how they may affect the current landscape of clinical practices. We hope that this review will update our current understanding of SNA, organized oligonucleotide aggregates, for disease diagnosis and treatment.

Imaging cancer cells with nanostructures: Prospects of nanotechnology driven non-invasive cancer diagnosis

The application of nanostructured materials in medicine is a rapidly evolving area of research that includes both the diagnosis and treatment of various diseases. Metals, metal oxides and carbon-based nanomaterials have shown much promise in medical technological advancements due to their tunable physical, chemical and biological properties. The nanoscale properties, especially the size, shape, surface chemistry and stability makes them highly desirable for diagnosing and treating various diseases, including cancers. Major applications of nanomaterials in cancer diagnosis include in vivo bioimaging and molecular marker detection, mainly as image contrast agents using modalities such as radio, magnetic resonance, and ultrasound imaging. When a suitable targeting ligand is attached on the nanomaterial surface, it can help pinpoint the disease site during imaging. The application of nanostructured materials in cancer diagnosis can help in the early detection, treatment and patient follow-up . This review aims to gather and present the information regarding the application of nanotechnology in cancer diagnosis. We also discuss the challenges and prospects regarding the application of nanomaterials as cancer diagnostic tools.

Prodrug-Based Versatile Nanomedicine with Simultaneous Physical and Physiological Tumor Penetration for Enhanced Cancer Chemo-Immunotherapy

Chemo-immunotherapy combination effect remains to be a great challenge due to the poor tumor penetration of therapeutic agents that resulted from condensed extracellular matrix (ECM), T cell-related immune escape, and thus the potential recurrence. Herein, a helix self-assembly camptothecin (CPT) prodrug with simultaneous physical and physiological tumor penetration was constructed to realize effective chemo-immunotherapy. Specifically, CPT was modified with arginine to self-assemble into nanofibers to physically improve tumor penetration. Two plasmids, pshPD-L1 and pSpam1 for expressing small hairpin RNA PD-L1 and hyaluronidase, respectively, were loaded to down-regulate tumor surface PD-L1 expression for converting anergic state of T cells into the tumor-reactive T cells and produce hyaluronidase to physiologically degrade ECM for further enhanced tumor penetration. Moreover, the degraded ECM could also increase immune cells' infiltration into tumor sites, which may exert a synergistic antitumor immunity combined with immune checkpoint inhibition. Such a nanomedicine could cause significant inhibition of primary, distant tumors, and effective prevention of tumor recurrence.