Synthesis and pharmacological activity of a novel water-soluble hepatocyte-specific polymeric prodrug of prostaglandin E 1 using lactosylated poly( l -glutamic hydrazide) as a carrier 1 1Abbreviations: PGE1, prostaglandin E1; PLGA-HZ, poly(l-glutamic hydrazide); Lac-NH-PLGA, lactosylated poly(l-glutamic hydrazide); PGE1 conjugate, prostaglandin E1 prodrug using Lac-NH-PLGA as a carrier; DTPA anhydride, diethylenetriamine-N,N,N′,N″,N″-pentaacetic dianhydride; GPT, glutamic pyruvic transaminase; AUC, area under the plasma concentration-time curve; ROS, reactive oxygen species; and EP receptor, receptor for prostaglandins expressed on a plasma membrane.