OBJECTIVETo investigate a new strategy of polylactic acid (PLA) nanoparticles delivery system coating nuclear factor-kappaB (NF-kappaB) decoy oligonucleotides (ODNs) for inhibiting TF expression in cultured brain microvascular endothelial cells(BMECs).

METHODSPLA nanoparticles coating FITC-labeled NF-kappaB decoy ODNs were formulated by nano-deposition method and the characteristics of nanoparticles were detected. BMECs were isolated and cultured in vitro. The cellular uptake and intracellular localization of nanoparticles in BMECs was detected by flow cytometry and confocal microscopy. Changes in the expressions of TF and nuclear protein P65 were examined by RT-PCR and Western blot in NF-kappaB decoy ODNs transfected BMECs by LPS stimulation.

RESULTSThe decoy-nanoparticles obtained were uniform spherical particles with an effective diameter of 162.1 nm and a polydispersity index of 0.118. NF-kappaB decoy ODNs encapsulated in nanoparticles could be released in a controlled manner in phosphate-buffered saline for up to 28 days. It was observed that the cellular uptake of nanoparticles were increased with the time of incubation and the concentration of nanoparticles in the medium. Nanoparticles localized mainly in the BMECs cytoplasm. LPS-induced upregulation of TF transcription was inhibited by NF-kappaB decoy ODNs transfection but not by missense ODNs transfection. Furthermore, changes in the transcription level of TF were paralleled by a reduction of capacity of P65 in nuclear extract of NF-kappaB decoy ODNs transfected cells.

CONCLUSIONSThese findings offer a potential therapeutic strategy in the control of TF expression in BMECs in vitro.