HPC EVs were more effective to attenuate mice renal I/R injury than normoxic EVs. (a) EV tracing in treated IRI kidney, green boxes indicate the location of representative EVs (Red), magnification 400×. (b) Representative renal sections from different groups (PAS staining, magnification 400×). (c) Renal injury scoring and quantitative analysis for different groups. (d) Serum creatinine levels in different groups. (Groups: sham surgery (SHAM), renal ischaemia reperfusion injected with PBS (IR+PBS), with EVs from HK2 cells cultured under normoxic conditions (IR+NOR EV) or with EVs from HPC HK2 cells (IR+HPC EV); *, #, P<0.05 compared with SHAM, IRI+PBS, respectively).