Figure 2.

LPPC protected BP against the loss of its antitumor activity in protein-rich, oxygenic, and acid/alkaline solutions.

Notes: (A) IC₅₀ of BP and BP/LPPC in DBTRG-05MG and RG2 cells. BP and BP/LPPC were preincubated in (B) H₂O or (C) 10% FBS solution at 37°C, after which both GBM cell lines were treated with the preincubated BP or BP/LPPC. As the preincubation time increased, the IC₅₀ values for BP and BP/LPPC were determined. *P<0.05, compared with DBTRG-BP in H₂O; ^#P<0.05, compared with RG2-BP in H₂O. BP and BP/LPPC were also preincubated in (D) H₂O or (E) 10% FBS solutions ranging from pH 6 to 8 at 37°C, after which both GBM cell lines were treated with the preincubated BP or BP/LPPC. The IC₅₀ values of BP and BP/LPPC were measured by MTT. BP and BP/LPPC were preincubated in (F) H₂O with oxygen or (G) 10% FBS solution with oxygen for 24 hours, and their IC₅₀ values in DBTRG-05MG cells were determined. *P<0.05, compared with nonencapsulated BP. (H) The cytotoxic activity of BP/LPPC in storage.

Abbreviations: BP, n-butylidenephthalide; FBS, fetal bovine serum; GBM, glioblastoma multiforme; IC₅₀, 50% inhibitory concentration; LPPC, lipo-PEG-PEI complex.