Objective:To prepare liposomes of paeonol modified with vascular endothelial growth factor(VEGF) antibody for preventing and treating hypertrophic scars

and establish its quality evaluation method

as well as study on its dermal retention effect. Method:The liposomes of paeonol modified with VEGF antibody were prepared by thin-film dispersion-ultrasonic method.Taking encapsulation efficiency as index

Box-Behnken response surface methodology was used to optimize the preparation process.The morphology of the liposomes was observed by transmission electron microscopy

particle size and Zeta potential were measured by particle size analyzer

dermal retention effect of the liposomes was determined by Franz diffusion cell method. Result:The optimal preparation conditions were as follows:phospholipid concentration of 7.36 g·L-1

lecithin-cholesterol-paeonol-(pNP-PEG3000-DOPE)-(BVE-PEG3000-DOPE)(14:5:4:0.28:0.05)

film forming temperature of 41℃

stripping with pH 7.5 sodium dihydrogen phosphate buffer solution

ultrasonic time of 3 min(ultrasonic time of 2 s

the interval of 3 s

power of 300 W);under these conditions

encapsulation efficiency of the liposomes was (73.61±2.36)%

particle size was (235.7±4.67) nm and Zeta potential was -(5.13±0.25) mV.Transdermal rate of liposomes of paeonol modified with VEGF antibody was slow and its dermal retention effect was remarkable. Conclusion:This optimized preparation process is reasonable and feasible with high encapsulation efficiency

good in vitro transdermal properties and sustained release effect.Liposomes of paeonol modified with VEGF antibody has obvious retention effect in the dermis layer

which is significantly higher than paeonol liposomes and paeonol raw material.