Nanomaterial Applications in Photothermal Therapy for Cancer

Abstract

As a result of their unique compositions and properties, nanomaterials have recently seen a tremendous increase in use for novel cancer therapies. By taking advantage of the optical absorption of near-infrared light, researchers have utilized nanostructures such as carbon nanotubes, gold nanorods, and graphene oxide sheets to enhance photothermal therapies and target the effect on the tumor tissue. However, new uses for nanomaterials in targeted cancer therapy are coming to light, and the efficacy of photothermal therapy has increased dramatically. In this work, we review some of the current applications of nanomaterials to enhance photothermal therapy, specifically as photothermal absorbers, drug delivery vehicles, photoimmunological agents, and theranostic tools.

Keywords: ablation; cancer; combination therapy; metastatic; nanomaterials; photothermal therapy.

Figure 1

The use of supramolecular chemistry to engineer new nanomaterials in vivo. By assembling phototherapeutic nanoparticles in vivo as an aggregate of smaller nanoparticles, Cheng et al. are able to shorten the biological half-life of the nanomaterial and increase the biocompatibility. Reproduced with permission from [29], copyright © 2016, John Wiley and Sons.

Figure 2

Crystalline zeolitic imidazolate framework-8 encapsulates doxorubicin hydrochloride and gold nanorods for synergistic chemo-photothermal therapy. The efficacy of chemo-photothermal therapy was demonstrated both in vitro and in vivo. Reproduced with permission from [48]. Copyright © 2017, Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature.

Figure 3

Depiction of laser immunotherapy. Tumors treated with Laser Immunotherapy release damage-associated molecular patterns (DAMPs), which, alongside glycated chitosan (GC), stimulate dendritic cell maturation and antigen presentation. This leads to activation and proliferation of CD8⁺ killer T-cells and a systemic antitumor immune response.

Figure 4

Proposed mechanism of nanomaterial-enhanced photoimmunological therapy. Tumors treated with SWCNT PTT can instigate a systemic immune response to treat metastatic cancers that can be potentiated through anti-CTLA-4 checkpoint inhibitor therapy. Reproduced with permission from [57]. Copyright © 2014 John Wiley and Sons.

Figure 5

Iron oxide nanocrystal-modified graphene oxide nanoparticle (GO-IONP) synthesis and application as theranostic agent. The graphene oxide acted as an effective photothermal absorber while the iron oxide nanocrystals could simultaneously act as a contrast agent in MRI imaging. Reproduced with permission from [45]; Copyright © 2012 Springer Nature.