The dependence of radio-sensitization efficiency on mitochondrial targeting with NaGdF4:Yb,Er nanoparticles

Dye-sensitized lanthanide-doped upconversion nanoprobes for homocysteine sensing in human serum and living cells via a spatial optimization strategy

Homocysteine (Hcy) is an established risk factor for cardiovascular and neurodegenerative diseases, making its real-time detection critical for maintaining physiological balance and monitoring disease progression. However, developing probes that specifically recognize Hcy with a high signal-to-background ratio remains a significant challenge. In this study, we present a novel upconversion nanoprobe for Hcy detection, which integrates NIR cyanine dyes (CyPd) with β-NaGdF4:Yb20%,Er2%@NaGdF4:Yb10%,Nd10% upconversion nanoparticles (UNs). CyPd, featuring α,β-unsaturated ketone and pyridine functional groups, serves as both an efficient energy donor and a recognition antenna for the UNs. Benefiting from a hydrogen bonding-assisted two-site strategy of CyPd, coupled with highly efficient energy transfer from CyPd to UNs, the nanoprobe demonstrates high selectivity and sensitivity for Hcy in aqueous solutions, achieving a low detection limit of 0.19 μM. Importantly, the nanoprobe exhibits excellent performance in human serum, with recovery rates ranging from 97.9% to 103.2% and a low relative standard deviation of less than 3.51%. Furthermore, it was successfully applied for both exogenous and endogenous Hcy bioimaging. This innovative nanoprobe offers a promising tool for the accurate and efficient detection of Hcy, with potential applications in disease diagnosis and monitoring.

Radiosensitization of Rare-Earth Nanoparticles Based on the Consistency Between Its K-Edge and the X-Ray Bremsstrahlung Peak

Nanoparticle-based X-ray radiosensitization strategies have garnered significant attention in recent years. However, the underlying mechanisms of radiosensitization remain incompletely understood. In this work, we explore the influence of the K-edge effect in the X-ray absorption of nanomaterials on sensitization. Due to the alignment of the K-edge of thulium (Tm) with the Bremsstrahlung peak in the energy spectrum of medical X-ray accelerators, the following four different rare-earth nanomaterials with varying Tm percentages were designed: NaTmF4, NaTm0.6Lu0.4F4, NaTm0.4Lu0.6F4, and NaLuF4. We evaluated the X-ray absorption and the ability to generate secondary electrons and reactive oxygen species (ROS) of these nanoparticles. The radiosensitizing effect was evaluated through clonogenic assays. Our results showed that the K-edge effect affected secondary electron generation but did not significantly change ROS production. Nonetheless, NaTmF4 induced marginally more DNA damage in the U87 cells than the other cell types. NaTmF4 also exhibited superior radiosensitization efficacy against the U87 tumor cells. This shows that secondary electrons and ROS play pivotal roles in radiosensitization, which might be crucial to improving cancer treatment efficacy through enhanced radiation therapy outcomes.

Nanomedicine embraces cancer radio-immunotherapy: mechanism, design, recent advances, and clinical translation

Cancer radio-immunotherapy, integrating external/internal radiation therapy with immuno-oncology treatments, emerges in the current management of cancer. A growing number of pre-clinical studies and clinical trials have recently validated the synergistic antitumor effect of radio-immunotherapy, far beyond the "abscopal effect", but it suffers from a low response rate and toxicity issues. To this end, nanomedicines with an optimized design have been introduced to improve cancer radio-immunotherapy. Specifically, these nanomedicines are elegantly prepared by incorporating tumor antigens, immuno- or radio-regulators, or biomarker-specific imaging agents into the corresponding optimized nanoformulations. Moreover, they contribute to inducing various biological effects, such as generating in situ vaccination, promoting immunogenic cell death, overcoming radiation resistance, reversing immunosuppression, as well as pre-stratifying patients and assessing therapeutic response or therapy-induced toxicity. Overall, this review aims to provide a comprehensive landscape of nanomedicine-assisted radio-immunotherapy. The underlying working principles and the corresponding design strategies for these nanomedicines are elaborated by following the concept of "from bench to clinic". Their state-of-the-art applications, concerns over their clinical translation, along with perspectives are covered.

Multifunctional high-Z nanoradiosensitizers for multimodal synergistic cancer therapy

Radiotherapy (RT) is one of the most common and effective clinical therapies for malignant tumors. However, there are several limitations that undermine the clinical efficacy of cancer RT, including the low X-ray attenuation coefficient of organs, serious damage to normal tissues, and radioresistance in hypoxic tumors. With the rapid development of nanotechnology and nanomedicine, high-Z nanoradiosensitizers provide novel opportunities to overcome radioresistance and improve the efficacy of RT by deposition of radiation energy through photoelectric effects. To date, several types of nanoradiosensitizers have entered clinical trials. Nevertheless, the limitation of the single treatment mode and the unclear mechanism of nanoparticle radiosensitization have hindered the further development of nanoradiosensitizers. In this review, we systematically describe the interaction mechanisms between X-rays and nanomaterials and summarize recent advances in multifunctional high-Z nanomaterials for radiotherapeutic-based multimodal synergistic cancer therapy. Finally, the challenges and prospects are discussed to stimulate the development of nanomedicine-based cancer RT.

Emerging Bismuth Chalcogenides Based Nanodrugs for Cancer Radiotherapy

Radiotherapy (RT), as one of the main methods of clinical tumor treatment, has been applied to the treatment of most solid tumors. However, the effect of RT is compromised by the radiation resistance of tumor hypoxic environment and non-specific damage caused by high-dose radiation. Bismuth chalcogenides (Bi2X3, X = S, Se) based nanodrugs have attracted widespread attention as highly efficient radiosensitizers due to their high photoelectric effect and excellent biocompatibility. More importantly, specially designed nanocomposites can effectively alleviate the radiation resistance of tumor tissues. Here, for the first time, we systematically summarize the latest progresses of Bi2X3 nanodrugs to enhance RT by alleviating the hypoxic tumor microenvironment. These emerging Bi2X3 nanodrugs mainly include three aspects, which are Bi2X3 nanocomposites with high-efficient O2 supply, non-O2-dependent Bi2X3 nanocomposites RT enhancers, and Bi2X3 nanocomposites-based photothermal-enhanced radiosensitizers. These Bi2X3 nanodrugs can effectively overcome the RT resistance of tumor hypoxic microenvironment, and have extremely high therapeutic effects and clinical application prospects. Finally, we put forward the challenges and prospects of Bi2X3 nanomaterials in the field of RT.