RÉSUMÉ
Objective To prepare multi-modality melanin-based lipid nanobubbles (MNBs) contrast agents,and to investigate their manifestations of ultrasound (US),photoacoustic (PA) and MRI in vitro.Methods MNBs and lipid nanobubbles (NBs) were prepared with the method of CHCl3-injection,freeze-drying and C3F8-inflation.The characteristics (shape,grain diameter,loading capacity of melanin and stability) of MNBs were obseved.US,PA and MRI were detected in vitro and the images were quantitatively analyzed.Results MNBs presented with homogenized size distribution,and transmission electron microscope (TEM) images demonstrated that the melanin particles were successfully entrapped into nanobubbles.Meanwhile,the loading capacity of melanin was 90.53 μg/mg.US signal increased in vitro with the rise of MNBs and NBs concentration.The ultrasonic manifestations of MNBs and NBs were the same,and the relative signal enhancement had no significant difference (P＞0.05).With the increased concentration of MNBs,the PA and MRI signals were stronger,but NBs showed no evident enhancement.Conclusion Multi-modality MNBs contrast agents are prepared successfully,which can enhance US,PA and MR imaging.
RÉSUMÉ
Objective To prepare multi-modality melanin-based lipid nanobubbles (MNBs) contrast agents,and to investigate their manifestations of ultrasound (US),photoacoustic (PA) and MRI in vitro.Methods MNBs and lipid nanobubbles (NBs) were prepared with the method of CHCl3-injection,freeze-drying and C3F8-inflation.The characteristics (shape,grain diameter,loading capacity of melanin and stability) of MNBs were obseved.US,PA and MRI were detected in vitro and the images were quantitatively analyzed.Results MNBs presented with homogenized size distribution,and transmission electron microscope (TEM) images demonstrated that the melanin particles were successfully entrapped into nanobubbles.Meanwhile,the loading capacity of melanin was 90.53 μg/mg.US signal increased in vitro with the rise of MNBs and NBs concentration.The ultrasonic manifestations of MNBs and NBs were the same,and the relative signal enhancement had no significant difference (P＞0.05).With the increased concentration of MNBs,the PA and MRI signals were stronger,but NBs showed no evident enhancement.Conclusion Multi-modality MNBs contrast agents are prepared successfully,which can enhance US,PA and MR imaging.