Nano-encapsulated tanshinone IIA in PLGA-PEG-COOH inhibits apoptosis and inflammation in cerebral ischemia/reperfusion injury

Tanshinone IIA has a potential therapeutic effect on cerebral ischemia/reperfusion injury (CIRI). In this study, tanshinone IIA was encapsulated in poly(lactic- co -glycolic acid)-block-poly (ethylene glycol)-carboxylic acid (PLGA-PEG-COOH) nanoparticles, and its therapeutic efficacy on CIRI was investigated. Morphology and dynamic light scattering analyses were performed to identify and optimize nano-formulations. A drug release test was conducted using the dialysis method. The cytotoxic effect of tanshinone IIA on human neuroblastoma cells (SH-SY5Y) and brain endothelial capillary cells (hCMEC/D3) was measured using the MTT assay. The protective effect of PLGA-PEG-COOH-encapsulated tanshinone IIA against CIRI was evaluated in oxygen and glucose deprivation/reoxygenation-induced SH-SY5Y/IR cells and middle cerebral artery occlusion (MCAO) rats. Results showed that PLGA-PEG-COOH-encapsulated tanshinone IIA promoted viability and inhibited apoptosis of SH-SY5Y/IR cells ( P < 0.01). Moreover, PLGA-PEG-COOH-encapsulated tanshinone IIA facilitated the invasion of SH-SY5Y/IR cells and repressed inflammation in MCAO rats ( P < 0.01). Noteworthy, PLGA-PEG-COOH-encapsulated tanshinone IIA combined with angiopep-2 peptide presented a better inhibitory effect on CIRI than tanshinone IIA alone ( P < 0.01). Angiopep-2 peptide contributes to traversing blood–brain barrier by recognizing lipoprotein-related protein expressed in the brain capillary endothelial cells. In conclusion, PLGA-PEG-COOH-encapsulated tanshinone IIA plus angiopep-2 peptide holds promising therapeutic potential toward CIRI.