Radiosensitizing effects of different size bovine serum albumin-templated gold nanoparticles on H22 hepatoma-bearing mice

Niosomes loaded with gold nanoparticles for enhanced radiation therapy in lung cancer

Aim: The present investigation aimed to develop niosomes containing gold nanoparticles (Nio-AuNPs) and to evaluate the combinational effect of Nio-AuNPs and x-ray radiation therapy (XRT) on growth inhibition potential and induction of apoptosis in the A549 cell line.Materials & methods: Gold nanoparticles (AuNPs) were synthesized, and niosomes were prepared using the thin-film hydration method. Various techniques were employed to determine their physiochemical characteristics. MTT assay, cell apoptosis analysis and combination index analysis were conducted to evaluate the therapeutic feasibility of Nio-AuNPs combined with XRT.Results: The combination of Nio-AuNPs and XRT resulted in greater cytotoxicity compared with XRT alone or with AuNPs.Conclusion: The AuNPs-loaded niosomal formulation enhances the efficacy of XRT on lung cancer cells in vitro, presenting a promising and effective therapeutic strategy.

Application of High-Z Nanoparticles to Enhance Current Radiotherapy Treatment

Radiotherapy is an essential component of the treatment regimens for many cancer patients. Despite recent technological advancements to improve dose delivery techniques, the dose escalation required to enhance tumor control is limited due to the inevitable toxicity to the surrounding healthy tissue. Therefore, the local enhancement of dosing in tumor sites can provide the necessary means to improve the treatment modality. In recent years, the emergence of nanotechnology has facilitated a unique opportunity to increase the efficacy of radiotherapy treatment. The application of high-atomic-number (Z) nanoparticles (NPs) can augment the effects of radiotherapy by increasing the sensitivity of cells to radiation. High-Z NPs can inherently act as radiosensitizers as well as serve as targeted delivery vehicles for radiosensitizing agents. In this work, the therapeutic benefits of high-Z NPs as radiosensitizers, such as their tumor-targeting capabilities and their mechanisms of sensitization, are discussed. Preclinical data supporting their application in radiotherapy treatment as well as the status of their clinical translation will be presented.

Hybridized quantum dot, silica, and gold nanoparticles for targeted chemo-radiotherapy in colorectal cancer theranostics

Multimodal nanoparticles, utilizing quantum dots (QDs), mesoporous silica nanoparticles (MSNs), and gold nanoparticles (Au NPs), offer substantial potential as a smart and targeted drug delivery system for simultaneous cancer therapy and imaging. This method entails coating magnetic GZCIS/ZnS QDs with mesoporous silica, loading epirubicin into the pores, capping with Au NPs, PEGylation, and conjugating with epithelial cell adhesion molecule (EpCAM) aptamers to actively target colorectal cancer (CRC) cells. This study showcases the hybrid QD@MSN-EPI-Au-PEG-Apt nanocarriers (size ~65 nm) with comprehensive characterizations post-synthesis. In vitro studies demonstrate the selective cytotoxicity of these targeted nanocarriers towards HT-29 cells compared to CHO cells, leading to a significant reduction in HT-29 cell survival when combined with irradiation. Targeted delivery of nanocarriers in vivo is validated by enhanced anti-tumor effects with reduced side effects following chemo-radiotherapy, along with imaging in a CRC mouse model. This approach holds promise for improved CRC theranostics.

The Refined Application and Evolution of Nanotechnology in Enhancing Radiosensitivity During Radiotherapy: Transitioning from Gold Nanoparticles to Multifunctional Nanomaterials

Radiotherapy is a pivotal method for treating malignant tumors, and enhancing the therapeutic gain ratio of radiotherapy through physical techniques is the direction of modern precision radiotherapy. Due to the inherent physical properties of high-energy radiation, enhancing the therapeutic gain ratio of radiotherapy through radiophysical techniques inevitably encounters challenges. The combination of hyperthermia and radiotherapy can enhance the radiosensitivity of tumor cells, reduce their radioresistance, and holds significant clinical utility in radiotherapy. Multifunctional nanomaterials with excellent biocompatibility and safety have garnered widespread attention in tumor hyperthermia research, demonstrating promising potential. Utilizing nanotechnology as a sensitizing carrier in conjunction with radiotherapy, and high atomic number nanomaterials can also serve independently as radiosensitizing carriers. This synergy between tumor hyperthermia and radiotherapy may overcome many challenges currently limiting tumor radiotherapy, offering new opportunities for its further advancement. In recent years, the continuous progress in the synthesis and design of novel nanomaterials will propel the future development of medical imaging and cancer treatment. This article summarizes the radiosensitizing mechanisms and effects based on gold nanotechnology and provides an overview of the advancements of other nanoparticles (such as bismuth-based nanomaterials, magnetic nanomaterials, selenium nanomaterials, etc.) in the process of radiation therapy.

Critical parameters to translate gold nanoparticles as radiosensitizing agents into the clinic

Radiotherapy is an inevitable choice for cancer treatment that is applied as combinatorial therapy along with surgery and chemotherapy. Nevertheless, radiotherapy at high doses kills normal and tumor cells at the same time. In addition, some tumor cells are resistant to radiotherapy. Recently, many researchers have focused on high-Z nanomaterials as radiosensitizers for radiotherapy. Among them, gold nanoparticles (GNPs) have shown remarkable potential due to their promising physical, chemical, and biological properties. Although few clinical trial studies have been performed on drug delivery and photosensitization with lasers, GNPs have not yet received Food and Drug Administration approval for use in radiotherapy. The sensitization effects of GNPs are dependent on their concentration in cells and x-ray energy deposition during radiotherapy. Notably, some limitations related to the properties of the GNPs, including their size, shape, surface charge, and ligands, and the radiation source energy should be resolved. At the first, this review focuses on some of the challenges of using GNPs as radiosensitizers and some biases among in vitro/in vivo, Monte Carlo, and clinical studies. Then, we discuss the challenges in the clinical translation of GNPs as radiosensitizers for radiotherapy and proposes feasible solutions. And finally, we suggest that certain areas be considered in future research. This article is categorized under: Therapeutic Approaches and Drug Discovery > NA.

Albumin-Modified Gold Nanoparticles as Novel Radiosensitizers for Enhancing Lung Cancer Radiotherapy

Background

Considering the strong attenuation of photons and the potential to increase the deposition of radiation, high-atomic number nanomaterials are often used as radiosensitizers in cancer radiotherapy, of which gold nanoparticles (GNPs) are widely used.

Materials and Methods

We prepared albumin-modified GNPs (Alb-GNPs) and observed their radiosensitizing effects and biotoxicity in human non-small-cell lung carcinoma tumor-bearing mice models.

Results

The prepared nanoparticles (Alb-GNPs) demonstrated excellent colloidal stability and biocompatibility at the mean size of 205.06 ± 1.03 nm. Furthermore, clone formation experiments revealed that Alb-GNPs exerted excellent radiosensitization, with a sensitization enhancement ratio (SER) of 1.432, which is higher than X-ray alone. Our in vitro and in vivo data suggested that Alb-GNPs enabled favorable accumulation in tumors, and the combination of Alb-GNPs and radiotherapy exhibited a relatively greater radiosensitizing effect and anti-tumor activity. In addition, no toxicity or abnormal irritating response resulted from the application of Alb-GNPs.

Conclusion

Alb-GNPs can be used as an effective radiosensitizer to improve the efficacy of radiotherapy with minimal damage to healthy tissues.

Radiosensitizing Fe-Au nanocapsules (hybridosomes®) increase survival of GL261 brain tumor-bearing mice treated by radiotherapy

Glioblastoma remains a cancer for which the effectiveness of treatments has shown little improvement over the last decades. For this pathology, multiple therapies combining resection, chemotherapy and radiotherapy remain the norm. In this context, the use of high-Z nanoparticles such as gold or hafnium to potentiate radiotherapy is attracting more and more attention. Here, we evaluate the potentiating effect of hollow shells made of gold and iron oxide nanoparticles (hybridosomes®) on the radiotherapy of glioblastoma, using murine GL261-Luc⁺ brain tumor model. While iron oxide seems to have no beneficial effect for radiotherapy, we observe a real effect of gold nanoparticles-despite their low amount-with a median survival increase of almost 20% compared to radiotherapy only and even 33% compared to the control group. Cellular and in vivo studies show that a molecule of interest nano-precipitated in the core of the hybridosomes® is released and internalized by the surrounding brain cells. Finally, in vivo studies show that hybridosomes® injected intra-tumorally are still present in the vicinity of the brain tumor more than 5 days after injection (duration of the Stupp protocol's radiation treatment). Interestingly, one mouse treated with radiotherapy in the presence of gold-containing hybridosomes® survived 78 days. Monitoring of the tumoral growth of this long-term survivor using both MRI and bioluminescence revealed a decrease of the tumor size after treatment. These very encouraging results are a proof-of-concept that hybridosomes® are really effective tools for the development of combined therapies (chemo-radiotherapy).

Gold Nanoparticles as Radiosensitizers in Cancer Radiotherapy

The rapid development of nanotechnology offers a variety of potential therapeutic strategies for cancer treatment. High atomic element nanomaterials are often utilized as radiosensitizers due to their unique photoelectric decay characteristics. Among them, gold nanoparticles (GNPs) are one of the most widely investigated and are considered to be an ideal radiosensitizers for radiotherapy due to their high X-ray absorption and unique physicochemical properties. Over the last few decades, multi-disciplinary studies have focused on the design and optimization of GNPs to achieve greater dosing capability and higher therapeutic effects and highlight potential mechanisms for radiosensitization of GNPs. Although the radiosensitizing potential of GNPs has been widely recognized, its clinical translation still faces many challenges. This review analyses the different roles of GNPs as radiosensitizers in cancer radiotherapy and summarizes recent advances. In addition, the underlying mechanisms of GNP radiosensitization, including physical, chemical and biological mechanisms are discussed, which may provide new directions for the optimization and clinical transformation of next-generation GNPs.

6H2L, a novel synthetic derivative of bifendate, induces apoptosis in hepatoma cells via mitochondrial and MAPK pathway

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. Our previous study indicated that 6H2L, a novel synthetic bifendate derivative, shows multidrug resistance reversal activity, while its antitumor effect has not been revealed. Here, the potent antitumor effects of 6H2L on hepatoma cells both in vitro and in vivo were investigated. 6H2L inhibited cell viability of HepG2 and SMMC-7721 cells with less sensitivity to normal human liver L-02 cells. 6H2L induced apoptosis in hepatoma cells. It upregulated Bax expression, while simultaneously decreasing Bcl-2 expression. Further elucidation of the mechanism revealed that 6H2L induced mitochondrial dysfunction, with transmitochondrial membrane potential collapse and cytochrome c release, which activated caspase-9 and caspase-3 and subsequently cleaved PARP, suggesting that 6H2L induced apoptosis via triggering mitochondrial pathway. Moreover, 6H2L decreased the phosphorylation of ERK1/2, whereas it increased the expression of p-JNK and p-p38. Then, specific inhibitors of the mitogen-activated protein kinase (MAPK) pathway were employed to confirm the roles of the MAPK pathway in the apoptosis-inducing effects of 6H2L. Additionally, 6H2L obviously inhibited the tumor growth in H22-bearing ICR mice. Meanwhile, 6H2L remarkably up-regulated Bax while suppressing Bcl-2 in tumors. Importantly, neither significant weight loss, white blood cell (WBC) count, nor histopathological abnormalities of major organs were observed in the mice receiving 6H2L treatment, indicating that 6H2L exerted strong anticancer activities with low toxicity in vivo. In contrast, fluorouracil inhibited tumor growth with significant decreased body weight and WBC count. Taken together, these results suggested 6H2L is a potential therapeutic candidate for HCC.

The Rational Design and Biological Mechanisms of Nanoradiosensitizers

Radiotherapy (RT) has been widely used for cancer treatment. However, the intrinsic drawbacks of RT, such as radiotoxicity in normal tissues and tumor radioresistance, promoted the development of radiosensitizers. To date, various kinds of nanoparticles have been found to act as radiosensitizers in cancer radiotherapy. This review focuses on the current state of nanoradiosensitizers, especially the related biological mechanisms, and the key design strategies for generating nanoradiosensitizers. The regulation of oxidative stress, DNA damage, the cell cycle, autophagy and apoptosis by nanoradiosensitizers in vitro and in vivo is highlighted, which may guide the rational design of therapeutics for tumor radiosensitization.

Enhanced melanoma cell-killing by combined phototherapy/radiotherapy using a mesoporous platinum nanostructure

BACKGROUND

Metal nanomaterials have a significant potential as photosensitizer and radiosensitizer. The purpose of this study was to evaluate the cytotoxicity of a platinum mesoporous nanostructure (Pt MN) toward a melanoma cancer cell line upon combined laser radiation (808 nm, 1 and 1.5 W cm^-2) and X-ray irradiation (6 MV, 2, 4, and 6 Gy).

METHODS

Pt MN was synthesized by a simple procedure and characterized by field emission scanning and transmission electron microscopy. A mouse malignant melanoma cell line C540 (B16/F10) was treated with Pt MN, laser light and/or X-ray.

RESULTS

Pt MN had a mesoporous structure with a sponge-resemble shape comprised of ensembles of very small adhered particles of <11 nm and about 5-nm pores. While Pt MN represented a low toxicity toward and considerable uptake into the cell line in a concentration range of 10-100 μg mL^-1, laser light radiation alone was also not toxic, and X-ray irradiation alone induced a limited toxicity, Pt MN was toxic against the cells in a dose dependent manner upon laser light radiation, X-ray irradiation, or their combined exposure. The killing efficacy of Pt MN upon X-ray irradiation was more obvious at 72 h post-treatment. The combined exposure (laser radiation followed by X-ray irradiation) led to a deep cell killing and a very low melanoma cell viability (∼1%). Significant melanoma cancer cell killing of Pt MN was due to reactive oxygen species (ROS) production upon combined exposure of laser and X-ray, while cell killing upon laser light radiation was due to heat generation.

CONCLUSION

Pt MN was introduced as a supreme laser/X-ray sensitizer for treatment of cancer with a high ability to produce ROS and a potent impact on decreasing cell viability.