Sonochemical preparation of folic acid-decorated reductive-responsive ε-poly-L-lysine-based microcapsules for targeted drug delivery and reductive-triggered release.

In this work, a versatile folic acid (FA) decorated reductive-responsive ε-poly-l-Lysine (ε-PL)-based microcapsules (FA-ε-PLMCs) were designed and facilely assembled by using sonochemical technique. Cellular uptake experiment of FA-ε-PLMCs loaded with Coumarin 6 (C6) as a model of hydrophobic drugs implied that hydrophobic drugs encapsulated inside FA-ε-PLMCs could be delivered selectively into Hela cells via folate-receptor (FR)-mediated endocytosis due to FA decorated on microcapsules. Furthermore, the shells of FA-ε-PLMCs cross-linked by disulfide bonds were derived from sulfhydryl groups (-SH) under ultrasonication. Under reductive environment, the hydrophobic drugs loaded in FA-ε-PLMCs would be easily released due to the cleavage of disulfide bonds. Benefiting from their suitable particle size, good loading capacity for hydrophobic drugs, remarkable targetability and reductive-triggered release, the obtained FA-ε-PLMCs could be a promising hydrophobic drugs carrier for the cancer treatment.