Preparation and Photocytotoxicity in vitro of Oridonin-porphyrin-chitosan Microspheres

A emulsion crosslinking method to prepare oridonin-porphyrin-chitosan microspheres with oridonin and 5-p-(6-bromohexylaminophenyl)- 10,15,20-triphenylporphyrin-chitosan (BHP-CS) is reported, which in turn was synthesized from 5-p-(6-bromo-hexylaminophenyl)-10,15,20-triphenylporphyrin (BHP) and chitosan. The porphyrin grafting rate of BHP-CS reached 30.80% on average, the drug loading rate and entrapment rate of the prepared microspheres reached 12.41% and 8.72% measured by HPLC, and the accumulated release rate was 81.74% in 48 h in vitro. The thiazolyl blue tetrazolium bromide (MTT) method was used to evaluate the photocytotoxicities of these derivatives against MCF-7 cells. The results revealed that oridonin-porphyrin-chitosan microspheres showed high photocytotoxicity in concentrations of 25, 50 and 100 mu mol/mL against MCF-7 cells, and the inhibit ratio of MCF-7 cells under light irradiation for 30 min were (31.55 +/- 1.70)%, (71.03 +/- 0.76)% and (82.74 +/- 0.38)%, respectively.