Fig. 2

a Cell viability of H/R injury H9c2 cell after treatment with different concentration of CsA, CsA@PLGA-PEG and CsA@PLGA-PEG-SS31. ^#p < 0.05 versus CsA group at the same concentration. b LDH release from H/R injury H9c2 cell after treatment with different concentration of CsA, CsA@PLGA-PEG and CsA@PLGA-PEG-SS31. ^##p < 0.01 versus CsA group at the same concentration, ^&&p < 0.01 versus CsA@PLGA-PEG group at the same concentration. c Cellular uptake of CsA, CsA@PLGA-PEG and CsA@PLGA-PEG-SS31 in H/R injured H9c2 cells (determined by HPLC). ^##p < 0.01 versus CsA group at the same time point, **p < 0.01 versus CsA@PLGA-PEG group at the same time point. d Relative uptake efficiency of CsA@PLGA-PEG-SS31 on H/R injured H9c2 cells at the presence of various endocytosis inhibitors, ATP depletion or 4 °C. **p < 0.01, *p < 0.05 versus control group