Transdermal delivery of 10,11-methylenedioxycamptothecin by hyaluronic acid based nanoemulsion for inhibition of keloid fibroblast.

This study designs an alternative transdermal delivery system for 10,11-methylenedioxycamptothecin(MD-CPT) to inhibit keloid. Hyaluronic acid nanoemulsions (HANs) with nano size, negative charge and good stability were prepared as transdermal carriers. The MD-CPT loaded HANs performed desirable skin permeable capacity across human keloid skin and the drug was transferred directly to keloid lesion area. MD-CPT was delivered percutaneously higher than the control group. FITC-HANs could be successfully internalized by keloid fibroblast (KF) and deliver MD-CPT toward nucleus, inhibited the proliferation of KF, while there was no serious toxicity to normal skin fibroblasts. The growth-inhibitory effect was further clarified upon cell cycle regulation, which arrested cells at G1/S and prevented them entry into mitosis. KF gene expression demonstrated plasminogen activator inhibitor-1 (PAI-1) was significantly down-regulated and Smad7 up-regulated, which was beneficial to inhibit keloid. The study demonstrated that as transdermal delivery of MD-CPT by HANs has potential for inhibition of keloid fibroblast.