ABSTRACT
In this study, a fluorescent nanoprobe based on liposome was synthesized by the hydrophobic interaction of phosphatidyl ethanolamine and indocyanine green (ICG). The nanoprobe was called LipoICG. In order to enhance the stability of liposome, we made a new LipoICG by coating it with human serum albumin (HSA). The new fluorescent nanoprobe, H-LipoICG, was produced for tumor imaging. The LipoICG and H-LipoICG were observed as spherical shape with uniform size distribution. The particle size of LipoICG was 94.47 nm, zeta potential was -43.5 mV and encapsulation efficiency (EE) was 81.5%. The particle size of H-LipoICG was 121.5 nm, zeta potential was -32.3 mV and EE was 98.2%. The coating of HSA could enhance the stability of liposome and increase the EE of ICG. Studies on drug release demonstrated that the release of ICG in H-LipoICG was slower than LipoICG, which suggests that HSA may reduce the ICG leakage from liposome, the fluorescence intensity could be enhanced in the nanoprobe. The Cell Counting Kit-8 assay demonstrated that LipoICG and H-LipoICG was not toxic for MCF-7 cells with good biocompatibility. In the study of biodistribution in mice, our experiments demonstrated that H-LipoICG had better tumor targeting ability and exhibited an enhanced fluorescence intensity than LipoICG. An optimize tumor contrast was observed after 8 h intravenous administration, the tumor margins could be clearly detected for up to 24 h after injection. So, H-LipoICG was an effective fluorescent probe for tumor imaging.