[Preparation and evaluation of a novel liposome-based fluorescent probe for tumor imaging].

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 m V and encapsulation efficiency (EE) was 81.5%.The particle size of H-LipoICG was 121.5 nm, zeta potential was-32.3 m V 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.

Preparation and In Vitro Evaluation of a Nano Ultrasound Contrast Agent Targeting Pancreatic Cancer.

To prepare a nano-sized ultrasound contrast agent that specifically targets pancreatic cancer cells and to evaluate its targeting effect In Vitro. PLGA-PEG-NHS was synthesized using PLGA, NHS, and PEG and detected using 1H-NMR. PLGA-PEG-NHS and PFOB were used to prepare PLGA nano contrast agent coated with PFOB by emulsification and volatilization, and then a hedgehog antibody was conjugated. The morphology of the nano contrast agent was observed using a transmission electron microscope, and its particle size and potential were measured using the dynamic light scattering method. The entrapment and drug loading efficiency of the nano contrast agent was measured using gas chromatography-mass spectrometry. The In Vitro release characteristics of the nano contrast agent was measured using the dialysis method. Human pancreatic cancer cell lines SW1990 and CFPAC1 were cultured in medium containing the nano contrast agent. The targeting ability of the nano contrast agent was qualitatively and quantitatively verified using fluorescence microscopy and flow cytometry. The average particle size of the targeted ultrasound contrast agent was 198.9 nm, zeta potential was -31.8 mv, entrapment rate was 63.7±3.9%, drug loading efficiency was 14.3±0.9%, and drug release was 85.3% in 48 h. In Vitro cell experiments showed that the targeted ultrasound contrast agent strongly bound to SW1990 cells with high expression of hedgehog antigen, but no specific binding was detected in CFPAC-1 cells which lack the hedgehog antigen. The nano ultrasound contrast agent prepared by emulsification and volatilization method can be potentially used for the diagnosis of pancreatic cancer.