Biodegradable π‑Conjugated Oligomer Nanoparticles with High Photothermal Conversion Efficiency for Cancer Theranostics LiXiaozhen LiuLu LiShengliang WanYingpeng ChenJia-Xiong TianShuang HuangZhongming XiaoYa-Fang CuiXiao XiangChengyang TanQinglong ZhangXiao-Hong GuoWeisheng LiangXing-Jie LeeChun-Sing 2019 We developed a biodegradable photothermal therapeutic (PTT) agent, π-conjugated oligomer nanoparticles (F8-PEG NPs), for highly efficient cancer theranostics. By exploiting an oligomer with excellent near-infrared (NIR) absorption, the nanoparticles show a high photothermal conversion efficiency (PCE) up to 82%, surpassing those of reported inorganic and organic PTT agents. In addition, the oligomer nanoparticles show excellent photostability and good biodegradability. The F8-PEG NPs are also demonstrated to have excellent biosafety and PTT efficacy both <i>in vitro</i> and <i>in vivo</i>. This contribution not only proposes a promising oligomer-based PTT agent but also provides insight into developing highly efficient nanomaterials for cancer theranostics.