NIR‐II absorbing organic nanoagents for photoacoustic imaging and photothermal therapy

• Published in: BMEmat (Print) Vol. 1; no. 1
• Main Authors: Shao, Wei, Zhao, Fulai, Xue, Jinhong, Huang, Lingling
• Format: Journal Article
• Language: English
• Published: Jinan John Wiley & Sons, Inc 01.03.2023; Wiley
• Subjects: Dyes; Glioma; Lasers; Ligands; Light; Nanoparticles; Nickel; NIR‐II; organic nanoagents; photoacoustic imaging; phototheranostics; photothermal therapy
• ISSN: 2751-7446; 2751-7438; 2751-7446
• DOI: 10.1002/bmm2.12009

Near‐infrared (NIR) absorbing materials hold great potential in biomedical applications, such as fluorescence imaging (FLI), photoacoustic imaging (PAI), photodynamic therapy (PDT), and photothermal therapy (PTT). Generally, these materials can be classified into two main categories based on their absorbing wavelengths: the first NIR (NIR‐I) (~650–950 nm) absorbing materials and the second NIR (NIR‐II) (~1000–1700 nm) absorbing materials. Due to the reduced absorption and scattering of NIR‐II light in tissue compared to NIR‐I light, NIR‐II absorbing materials enable imaging and therapy with improved contrast and deepened penetration, which is in favor of practical applications. Various inorganic materials have been developed for NIR‐II phototheranostics in recent years. However, the non‐biodegradability and potential toxicity of these materials hinder their further clinical translation. Biocompatible organic materials with potential biodegradability as well as tailored optical property are thus more desired. In this review, we summarize the recent advances of NIR‐II absorbing organic nanoagents (ONAs) based on small molecules (SMs) and conjugated polymers (CPs) for PAI and PTT and show our perspectives on future challenges and development of these materials. Emerging NIR‐II absorbing organic nanoagents (ONAs) are potent phototheranostic agents with improved imaging contrast and deepened tissue penetration. They have shown some superiorities over the inorganic ones, such as the biocompatibility and easily tailored properties. In this review, we summarize the recent advances of NIR‐II absorbing ONAs based on small molecules (SMs) and conjugated polymers (CPs) for diverse phototheranostic applications. Moreover, the challenges and future perspectives of this research area are also discussed.