Advanced nanomaterials targeting hypoxia to enhance radiotherapy

Abstract

Hypoxia within solid tumors is often responsible for the failure of radiotherapy. The development of hypoxia-targeting nanomaterials – aimed at enhancing the effect of radiotherapy by electrical or heat effects and at modulating hypoxia in the tumor microenvironment – is a promising strategy to address this issue. We provide an overview of recently developed advanced materials that potentiate radiotherapy. First, we summarize novel materials for oxygen delivery or production to modify the tumor microenvironment, thus improving the effects of ionizing radiation. Second, we present new approaches for the design of high-Z element–based multifunctional nanoplatforms to enhance radiotherapy. Third, novel drug delivery systems for hypoxic regions and hypoxia-inducible factor-1–targeted therapies are discussed. Fourth, we establish the effectiveness of X-ray- or near-infrared–responsive nanoparticles for selectively triggering therapeutic effects under hypoxic conditions. Finally, this review emphasizes the importance of research in the field of nanomedicine focused on tumor hypoxia to improve clinical outcomes.

<p>Gold Nanoparticles as Radiosensitizers in Cancer Radiotherapy</p>

“…Recently, bacteria have been widely applied to cancer therapy because of the selective targeting of hypoxic or anoxic regions which activates the immune response. 142 , 160 , 161 …”

“…Recently, bacteria have been widely applied to cancer therapy because of the selective targeting of hypoxic or anoxic regions which activates the immune response. 142,160,161 Inspired by these intrinsic advantages, Kefayat et al 162 utilized attenuated strains of Salmonella Typhi Ty21a (a motile facultative anaerobic organism) as radiosensitizers and smart carriers to deliver GNPs to hypoxic tumor regions. In this study, flow cytometry and ICP-OES were used to investigate the uptake of 7 different modified GNPs (Citrate-GNPs, Gelatin-GNPs, BSA-GNPs, FA-GNPs, Glutamine-citrate-GNPs, Glut-BSA-GNPs, Glu-BSA-GNPs) by Salmonella typhimurium Ty21a.…”

The Combination of Liposomes and Metallic Nanoparticles as Multifunctional Nanostructures in the Therapy and Medical Imaging—A Review

“…Moreover, hypoxia promotes the genetic transformation of cells into a more invasive phenotype, which further increases the predisposition to metastasis and disease recurrence [42]. In order to overcome those inconveniences, it has been proposed to use perfluorocarbons as O 2 carriers [43]. These types of compounds are characterized by high incorporation and easier penetration abilities through abnormal vascular structures in the tumor microenvironment.…”

The Rational Design and Biological Mechanisms of Nanoradiosensitizers

“…In this review, we summarize the recent progress made in NPs-induced radiosensitization by modulating multiple biological mechanisms. Hypoxia-related radiosensitive effects have been systematically reviewed by Li and Zhang et al [18,19] and, therefore, are not addressed in this review. The regulation of crucial cellular processes by the physicochemical properties of NPs in cancer cells is reviewed, which may guide the design of nanoradiosensitizers in the future.…”