Development and in vitro safety evaluation of pramipexole-loaded hollow mesoporous silica (HMS) particles

Abstract

In this study, spherical hollow mesoporous silica (HMS) particles with average size of 550 nm were loaded with dopamine-receptor agonist pramipexole, as a model drug. High drug loading (55%) was achieved by its incorporation in the reservoir structure of HMS. The newly developed drug-delivery systems were further double-coated with bioadhesive polymers chitosan and sodium alginate to achieve sustained release. The double chitosan/sodium alginate coating diminished the initial burst effect and lowered pramipexole release at two pH values (1.2 and 6.8) as shown by in vitro release studies. The haemolytic assay and MTT-test in human neuroblastoma SH-SY5Y cells showed good safety profile of the novel pramipexole-loaded HMS particles. Moreover, a more pronounced protection of human neuroblastoma SH-SY5Y cells against H2O2-induced oxidative damage was observed upon treatment with pramipexole-loaded (non-coated or chitosan-coated) HMS particles compared to the free drug. In conclusion, we found that HMS particles might be of great interest as a promising drug-delivery system for pramipexole. The coating with biopolymer chitosan modified both the drug-delivery process and the in vitro protection against oxidative stress in neuroblastoma SH-SY5Y cells.