(a) A549 cells were transfected with biotinylated eYFP carried by GNVs or Lipofectamine 2000. A representative image of transfected cells is shown (left panel). YFP-positive cells were quantitatively analysed by FACS (right panel). (b) PKH26–GNVs loaded with biotin-labelled anti-CD4 or anti-CD8 antibodies were incubated in vitro with splenocytes and the PKH26-positive cells were qualitatively analysed by FACS. Data (a,b) are representative of at least three independent experiments. (c) GNVs-encapsulating psiCHECK2 were loaded with biotin-labelled anti-CD4 or CD8 antibodies, and then incubated with mouse spleen CD4+ or CD8+ cells. After 24 h, the expression of luciferase in CD4 and CD8 cells was detected. The results indicate the activity of luciferase expressed in the transfected T cells (n=5). (d) The biological effect of luciferase-specific siRNA carried by GNVs or Lipofectamine 2000 on inhibition of luciferase activity of transfected GL26-luc and A549-luc cells was evaluated using a luciferase assay (n=3). *P<0.05, **P<0.01 and ***P<0.001 (one-way analysis of variance, ANOVA). Data are the mean±s.e.m. of at least three independent experiments.