| 内容提要: |
In this work, as the proof-of-concept, we designed a folic acid (FA)-grafted DiR loaded lipid-PANI nanoparticle (denoted as DLPNP), which exhibited FRET effect between DiR and PANI (Scheme 1a and b). In this nanosystem, lipid-PANI nanoparticle (LPNP) with π-π electronic conjugated system and broad NIR absorbance was selected as a model receptor owing to its effective photothermal conversion efficiency, targeting ability and high drug loading capacity. In order to obtain a multifunctional nanoplatform applied simultaneously for PTT, chemotherapy and imaging, rapamycin (RAPA) which could inhibit primary and metastatic tumor growth by antiangiogenesis was encapsulated into DLPNPs to form the RAPA/DiR loaded lipid-PANI nanoparticles (RDLPNPs). RDLPNP is hypothesized to accumulate in the tumor in a time dependent manner and provides PA imaging of biological tissues in the tumor site. Additionally, although RDLPNPs exhibited FRET effect upon irradiation, there were still some residual NIRF signals providing complementary information on PA from the whole body. Both fluorescent and enhanced PA imaging modalities are able to provide obvious tumor contrast in this study. At 6 h intravenous injection (i.v.), fluorescent and enhanced PA signals reached peak intensity in the tumor, indicating a high tumor uptake of RDLPNPs. Next, PTT was conducted on Hela tumor bearing mouse model, more RAPA would release from the RDLPNPs, and therapeutic response was monitored for 48 days. Compared with control groups, effective ablation of Hela tumors was achieved in vivo. Our results greatly motivate the application of RDLPNPs as a contrast agent for PA imaging and optical imaging to guide the enhanced photothermal effect and simultaneously as antiangiogenesis-photothermal therapeutic agents against tumors in vivo. |