Serum ELISA assay revealed significantly lower levels of markers of myocardial injury (MYO and c-TnI) at 4–5 h post-infarction in the PtNP-shell group compared to the control group (all p < 0.05, Fig. 5j, k), indicating an improvement in myocardial injury28. Here, TNNI3 is linked to infarction.