Objective: In this study

sterically stabilized liposomes (SSL) containing DiR-iodide fluorescent dye (DiR-SSL) was prepared

this liposome was performed on SD rats and BALB/c nude mice for in vivo targeting studies.HGRFG-5-FAM-SSL (HFL) was preparing by SSL loading Trionycis Carapax peptide containing 5-carboxylfluorescein(5-FAM) (HGRFG-5-FAM

HF)

and to investigate pharmacokinetics of administration by HF and HFL in rats

respectively. Method: DiR-SSL and HFL were prepared by thin-film dispersion method.HF and HFL were injected into the tail vein of two groups of SD rats

respectively;the concentration and dose of HF were the same.Plasma samples were collected at different time points and analyzed by multi-function microplate detector

and pharmacokinetic parameters were calculated.DiR-SSL was injected intravenously in BALB/c nude mice

the mice were in vivo imaged respectively at 1

2

5

7

24 h

and fluorescence values were read.The normal SD rats were injected DiR-SSL intravenously

after 24 h

the heart

liver

spleen

lung and kidney were imaged in fluorescence imaging system and fluorescence values were read

frozen sections of liver tissue were taken for confocal laser scanning. Result: After HF being injected into rats

its T1/2 was only 0.826 h;at the same dose

T1/2 and AUC0-∞ of HFL were 16.253 times and 11.899 times that of HF

respectively.In vivo fluorescence imaging of BALB/c nude mice showed fluorescence was mainly in the liver position and weakened gradually over time.The fluorescence of DiR-SSL in the liver of SD rats among different organs was strongest

DiR-SSL remained in the liver tissue at 24 h after injection. Conclusion: SSL drug delivery system can significantly extend T1/2 of HF in SD rats

and this system has a liver targeting effect

suggesting that this system can be used as drug carriers to realize liver targeted drug delivery.