Enabling Prussian Blue with Tunable Localized Surface Plasmon Resonances: Simultaneously Enhanced Dual-Mode Imaging and Tumor Photothermal Therapy

Abstract

Prussian blue (PB) has been used as a photothermal conversion agent to generate heat to induce localized damage to tumor. However, its therapeutic efficiency is far from satisfactory. One of the major obstacles is that the maximum NIR absorption peak of PB within 690-720 nm cannot be optimized near the wavelength of the laser to enhance its therapeutic efficiency. Herein, we report that the integration of Gd into PB nanocrystals (GPB NCs) enables PB with tunable localized surface plasmon resonances (LSPRs) from 710 to 910 nm, achieving the maximum NIR peak near the wavelength of the laser. Concurrently, the efficiency of dual-mode imaging including photoacoustic imaging and magnetic resonance imaging has been greatly improved. These enhancements in dual-mode imaging and photothermal therapy enable PB with low nanomaterial dose and laser flux. Additionally, it is found that GPB NCs show the capability of not only acting as a chemical probe with tunable sensitivity but also scavenging reactive oxygen species. The integration of functional ions into a photothermal conversion agent is an efficient strategy to improve the synergy of nanoagent, enchancing tumor theranostic efficiency.

Strategies to Improve Cancer Photothermal Therapy Mediated by Nanomaterials

“…The photothermal capacity of PB nanostructures has been improved by doping these materials with Mn 2+ and Gd 3+ . PEGylated PB nanocubes doped with 15% Mn 2+ displayed an almost 2‐fold increased NIR absorption that lead to an improved temperature variation (ΔT ≈ 10 °C), upon material irradiation …”

Plasmonic doped semiconductor nanocrystals: Properties, fabrication, applications and perspectives

“…Additionally, NCs of other materials were found to show NIR plasmonic response, such as colloidal GeTe NCs, [18] LaB 6 NCs, [19,20] and Gd doped Prussian Blue. [21] Degenerately doped semiconductor NCs form an exceptional case, as high levels of doping can be reached, leading to degeneracy of the doping levels. Carrier densities around 10 21 cm -3 place their LSPRs in the NIR, [2][3][4][5][6][7][8][9][10][11][12][13] and the high number of defect states leads to a widening of the bandgap in terms of the Moss-Burstein effect for heavily doped semiconductors.…”

NIR Light‐Triggered Degradable MoTe2Nanosheets for Combined Photothermal and Chemotherapy of Cancer

“…Photothermal therapy (PTT) is an emerging therapeutic modality based on the generation of a far‐infrared wave by an optically excited material . With the development of photothermic (PT) agents, such as conjugated organic groups, carbon nanotubes, and metal‐based nanocrystals, PTT has been widely used for tumor imaging and treatment . The specificity and selectivity of PT agents play a key role in the process of diagnosis and treatment .…”