Recent Advances in Metal-Based NanoEnhancers for Particle Therapy

Abstract

Radiotherapy is one of the most common therapeutic regimens for cancer treatment. Over the past decade, proton therapy (PT) has emerged as an advanced type of radiotherapy (RT) that uses proton beams instead of conventional photon RT. Both PT and carbon-ion beam therapy (CIBT) exhibit excellent therapeutic results because of the physical characteristics of the resulting Bragg peaks, which has been exploited for cancer treatment in medical centers worldwide. Although particle therapies show significant advantages to photon RT by minimizing the radiation damage to normal tissue after the tumors, they still cause damage to normal tissue before the tumor. Since the physical mechanisms are different from particle therapy and photon RT, efforts have been made to ameliorate these effects by combining nanomaterials and particle therapies to improve tumor targeting by concentrating the radiation effects. Metallic nanoparticles (MNPs) exhibit many unique properties, such as strong X-ray absorption cross-sections and catalytic activity, and they are considered nano-radioenhancers (NREs) for RT. In this review, we systematically summarize the putative mechanisms involved in NRE-induced radioenhancement in particle therapy and the experimental results in in vitro and in vivo models. We also discuss the potential of translating preclinical metal-based NP-enhanced particle therapy studies into clinical practice using examples of several metal-based NREs, such as SPION, Abraxane, AGuIX, and NBTXR3. Furthermore, the future challenges and development of NREs for PT are presented for clinical translation. Finally, we propose a roadmap to pursue future studies to strengthen the interplay of particle therapy and nanomedicine.

Understanding the Role of Radio-Sensitizing Nanoparticles in Enhancing Pathologic Response in Soft Tissue Sarcomas

“…The physical primary mode of action of high-Z nanoparticles in enhancing the antitumor effect of RT does not rely on biological pathways. Therefore, these nanoparticles can be applied in all solid tumors where RT is used as the primary treatment modality or as a neoadjuvant treatment, limited only by the feasibility of introducing nanoparticles into the tumor volume, especially for tumors of increased dimensions [25][26][27]52]. Hoffmann et al [53] conducted a phase I dose-escalation study to evaluate the safety profile of NBTXR3 activated by IMRT in elderly patients with locally advanced squamous cell carcinoma of the oral cavity or oropharynx.…”

Nanomedicine Strategies for Targeting Tumor Stroma

“…Beyond the field of cancer therapies, the use of nanomedicine in other disease areas, including lung disease [56], cardiovascular disease [57], and bone and cartilage disorders [58], has resulted in improved effectiveness as well. Currently, the FDA and European Medicines Agency (EMA) have authorized over 80 nanomedicine therapeutics [59], and more than 60 clinical studies are ongoing (clinicaltrials.gov, accessed May 2023).…”