Development of Janus-shaped gold nanoparticles for cancer treatment using highly biopermeable near-infrared light

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K19908
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 90:Biomedical engineering and related fields
• Research Institution: Hokkaido University
• Principal Investigator: Ijiro Kuniharu 北海道大学, 電子科学研究所, 教授 (90221762)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: 金ナノ粒子 / ヤヌス型ナノ粒子 / 自己集合 / 光免疫療法 / 近赤外 / 光熱変換

Outline of Final Research Achievements

In this research, we aimed to develop a photothermal therapeutic system to disrupt cancer cell membranes with gold nanoparticles (AuNPs) that absorb near-infrared (NIR) light. The AuNPs were modified with temperature-responsive ligands to express surfactant effect that destroys cell membranes via photothermal conversion. Firstly, a disc (AuND) was modified with a weakly hydrophobic ligand to provide temperature responsivity. As a result, it showed assembly/disassembly according to heating/cooling with good dispersibility. Next, a rod (AuNR) was mixed with cancer cells in a culture medium and irradiated with NIR light to demonstrate cell membrane disruption. As a result, cell viability was significantly reduced with NIR light irradiation. These results revealed that the photothermal conversion of AuNPs enables to induce the death of cancer cells with NIR light efficiently.

Free Research Field

コロイド化学、高分子化学、ナノマテリアル

Academic Significance and Societal Importance of the Research Achievements

近年、「第5のガン治療」として注目されている光免疫療法は、皮膚を透過する近赤外（NIR）光で色素を反応させ、ガン細胞を特異的に死滅させることができるが、細胞膜の破壊効率、色素分子の吸収波長、内在的な毒性の点で改善の余地がある。一方で、本研究により、金ナノ粒子の形状を制御することで、より生体透過性が高いNIR領域にプラズモン吸収波長を設定できることが明らかとなった。さらに、金ナノ粒子の光熱変換能により、NIR光でガン細胞の死滅を誘起できることが分かった。本研究で得られた成果により、標的細胞の破壊効率が高く、毒性を低減した新たな光免疫療法への応用展開が期待できる。