Background: Hepatic ischemia/reperfusion-induced pancreatic islet injury (HI/RIPII) was an important pathophysiological phenomenon in clinics. In the present study, we observed the effects of phycocyanin on HI/RIPII. However, the half-life of phycocyanin was extremely short and limited its use in vivo.
Materials and methods: In order to overcome this shortcoming, poly(ethylene glycol)-b -(poly(L-glutamic acid)-g -polyethylenimine) (PEG-b -(PG-g -PEI)) was synthesized and estimated as a nanocarrier for lengthening delivery of phycocyanin through the abdominal subcutaneous injection in rats. Phycocyanin (isoelectric point=4.3) was encapsulated with PEG-b -(PG-g -PEI) via electrostatic interactions at pH 7.4.
Results: In vitro phycocyanin was fast and efficiently encapsulated and showing efficient loading and sustained release. In vivo the anti-HI/RIPII function of phycocyanin/PEG-b -(PG-g -PEI) complex was surveyed in rats using free phycocyanin as the controls, and the results showed that phycocyanin/PEG-b -(PG-g -PEI) complex reduced HI/RIPII property and enlarged islet functionality. 
Conclusion: These results suggested that PEG-b -(PG-g -PEI) might be treated as a potential phycocyanin nanocarrier.
Keywords: phycocyanin, PEG-b -(PG-g -PEI), HI/RIPII, pancreatic islets