ABSTRACT
Objective To evaluate effects of 4-hydroxyphenyl retinamide (4-HPR) in different vehicles on the proliferation and apoptosis of human keloid fibroblasts (HKFs).Methods A film-ultrasonic dispersion method was used to prepare 4-HPR liposome solution and 4-HPR microbubbles.Primary HKFs were in vitro treated with the 4-HPR liposome solution at different concentrations of 0-80 mg/L for 6-48 hours,and the proliferative activity of HKFs was evaluated by methyl thiazolyl tetrazolium (MTT) assay.Some other HKFs were divided into 3 experimental groups to be treated with 15 mg/L 4-HPR solution (4-HPR solution group),15 mg/L 4-HPR liposome solution (4-HPR liposome solution group) and 15 mg/L 4-HPR microbubbles (4-HPR microbubble group),respectively,and each group was divided into ultrasonic-treated and-untreated subgroups.HKFs without treatment served as control group.After 24-hour treatment,MTT assay was conducted to evaluate the proliferative activity of HKFs in the above groups,flow cytometry to detect apoptosis of HKFs in all groups except the 4-HPR solution group.Results The 4-HPR liposome solution and 4-HPR microbubbles were successfully prepared.MTT assay showed inhibitory effects of 4-HPR liposome solution at concentrations of 1-80 mg/L on the proliferation of HKFs,and the proliferation inhibition rate was positively associated with the drug concentrations (r =0.633,P ＜ 0.01).After the ultrasonic treatment,inhibitory effects on the proliferation of HKFs significantly differed among the 4-HPR microbubble group,4-HPR solution group and 4-HPR liposome solution group (P ＜ 0.01).The 4-HPR liposome solution group and the 4-HPR microbubble group both showed significantly increased apoptosis rates (21.81％ ± 3.73％,39.79％ ± 1.61％,respectively) compared with the control group (6.18％ ± 0.61％,both P ＜ 0.01).Conclusion The 4-HPR microbubbles are successfully prepared,and 4-HPR in different vehicles all can promote HKF apoptosis and suppress HKF proliferation,among which,4-HPR microbubbles in combination with ultrasonic treatment have stronger inhibitory effects than the 4-HPR liposome solution.