Preparation of aFGF liposomes and their release behavior in vitro

Acidic fibroblast growth factors(aFGF) liposomes were prepared by pH-gradient loading.The formulation and preparation were optimized by the single-factor design regarding the encapsulation efficiency of aFGF.It consisted of stearylamine(0.02 g)，citric acid buffer(0.03 mol/L)，aFGF(0.04 mg/mL)，ΔpH(3.5)，incubation temperature(35 ℃)，and incubation time(15 min).Under this condition，the encapsulation efficiency ，Zeta potential and mean diameter of aFGF liposomes were (78.82±2.56)%，9.68 mV and 124.03 nm，respectively.Dialysis found that the release of aFGF liposomes were significantly delayed compared to aFGF solution.The stability of aFGF liposomes was greatly improved compared with that of aFGF solution，and the most appropriate storage temperature was 4 ℃. aFGF liposomes show high entrapment efficiency，good stability and significant sustained-release feature.