Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, PR China.
Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.
Biomaterials. 2016 Oct;104:352-60. doi: 10.1016/j.biomaterials.2016.07.030. Epub 2016 Jul 26.
The bacterial magnetic nanoparticles (BMPs) are biomineralized by the magnetotactic bacteria and naturally covered with a layer of biomembrane. Herein, BMPs were isolated and firstly used for the photothermal therapy (PTT) of cancer under the guidance of magnetic resonance imaging (MRI) in vitro and in vivo. The results showed that BMPs could rapidly convert the energy of 808 nm near-infrared (NIR) light into heat. After internalization by the HepG2 tumor cells, BMPs with good biocompatibility could induce an efficient killing effect after NIR light irradiation, along with a change of mitochondrial membrane potential (ΔΨm) and level of intracellular reactive oxygen species (ROS). The in vivo therapy also confirms that PTT with BMPs could effectively and completely ablate the tumor in mice without inducing observable toxicity. T2-weighted MRI showed a clear tumor boundary and a 25% enhancement of negative contrast enhancement at the tumor site, suggesting that BMPs can act as an effective MRI contrast agent for guiding the PTT. Our results indicate that BMPs could be a potential theranostic agent for simultaneous MRI and PTT of cancer.
细菌磁性纳米颗粒 (BMPs) 由趋磁细菌生物矿化，并自然覆盖一层生物膜。在此，BMPs 被分离出来，并首次在体外和体内磁共振成像 (MRI) 的指导下用于癌症的光热治疗 (PTT)。结果表明，BMPs 可以将 808nm 近红外 (NIR) 光的能量迅速转化为热量。在被 HepG2 肿瘤细胞内化后，具有良好生物相容性的 BMPs 在近红外光照射后可以诱导有效的杀伤作用，同时伴随着线粒体膜电位 (ΔΨm) 和细胞内活性氧 (ROS) 水平的变化。体内治疗也证实，BMPs 的 PTT 可以有效地完全消融小鼠的肿瘤，而不会引起可观察到的毒性。T2 加权 MRI 显示肿瘤边界清晰，肿瘤部位的负对比增强增强了 25%，表明 BMPs 可以作为一种有效的 MRI 造影剂，用于指导 PTT。我们的结果表明，BMPs 可能是一种用于癌症的同时 MRI 和 PTT 的潜在治疗剂。
