目前，NIR-II触发的光热生物医学应用受到复杂的合成反应、平庸的光热转换效率和难以降解的限制。在此，我们用简单的方法制备了可生物降解的双氧磷脂修饰的铋纳米花（BNFs），其在NIR-II下具有较高的光热转换效率（约为33.52%），并将其改性为红细胞膜和40号右旋糖基（DRBCM）以改善其体外稳定性、避免巨噬细胞清除并增强肿瘤积累。颗粒表面的右旋糖基覆层把无机颗粒稳定在化学上，通过维持表面电荷并在相邻聚合物链的压缩时产生立体互斥。体外和体内实验证明，DRBCM-BNFs的联合热辐射疗法比单一疗法表现出明显的肿瘤抑制效果，并具有良好的生物相容性和低毒性，因为它具有生物可降解性。此外，机理研究表明，DRBCM-BNFs可以作为纳米敏化剂，在NIR-II照明和X线辐射下促进热辐射疗法，通过下调热休克蛋白70（HSP70）和磷酸化-p65（p-p65）来减少肿瘤细胞的热阻力和放射阻力，并增加凋亡相关蛋白裂解的半胱氨酸天冬酶-3的表达。总之，DRBCM-BNFs可能是一个有前途的绿色传递平台，用于促进协同热辐射治疗的敏化作用。版权所有 © 2023 Elsevier Ltd。

At present, NIR-II-triggered photothermal biomedical applications are limited by complex synthesis reactions, mediocre photothermal conversion efficiency, and difficult degradation. Herein, we prepared biodegradable Bi flower-like nanoparticles (phospholipid-modified Bi nanoflowers, BNFs) with high photothermal conversion efficiency (∼33.52 %) in NIR-II by a simple method and then modified them with the red blood cell membrane and dextran 40 (DRBCM) to improve their in vitro stability, to escape macrophages clearance and to enhance tumor accumulation. Dextran coating onto the surface of particles as a dispersant shell stabilizes inorganic particles by maintaining the surface charges and creating steric repulsions upon compression of neighboring polymer chains. In vitro and in vivo experiments proved that combined thermoradiotherapy of DRBCM-BNFs exhibited significantly enhanced tumor inhibition efficacy than monotherapy with good biocompatibility and low toxicity due to its biodegradability. Furthermore, the mechanism studies demonstrated that DRBCM-BNFs could serve as a nano sensitizer to promote the thermoradiotherapy under NIR-II illumination and X-ray irradiation, by downregulating heat shock protein 70 (HSP70) and phosphorylated-p65 (p-p65) to reduce the thermal resistance and radioresistance of tumor cells and increasing the expression of apoptosis-related protein cleaved caspase-3. In conclusion, DRBCM-BNFs could be a promising green delivery platform for the sensitization of synergistic thermoradiotherapy.Copyright © 2023. Published by Elsevier Ltd.