Silk-fibroin-coated liposomes for long-term and targeted drug delivery

Many barriers to drug delivery into a tumor site require careful consideration when designing a new drug.In this study, the adhesive targeting and drug specificity of modified liposomal vesicles on human-scar-producing cells, keloid fibroblasts, were investigated.Keloids express abundant levels of mucopolysaccharides and receptor tyrosine kinase (RTK).In this report, the structural properties, drug release kinetics, and therapeutic availability of silkfibroin-coated, emodin-loaded liposomes (SF-ELP), compared with uncoated, emodin-loaded liposomes (ELP), were investigated.SF-ELP had a highly organized lamellae structure, which contributed to 55% of the liposomal diameter.This modified liposomal structure decreased emodin release rates by changing the release kinetics from a swelling and diffusional process to a purely diffusional process, probably due to steric hindrance.SF-ELP also increased adhesion targeting to keloid fibroblasts.Increased retention of SF-ELP is most likely due to the interaction of the fibrous protein coating around the ELP with the pericellular molecules around the cell.SF-ELP also decreased survival rate of keloids that expressed high levels of RTK.These results demonstrated that SF-ELP enhanced emodin delivery by improved diffusion kinetics and specific cell targeting.