부산대학교 도서관

pH-sensitive betulinic acid (BA) polymer prodrug nanoparticles, have been proposed. The carboxyl group-terminated poly[2-(3-butenyl)-2-oxazoline] (PBuOx-COOH) is prepared by cationic ring-opening polymerization (CROP) of the 2-(3-butenyl)-2-oxazoline (BuOx) using ethyl 3-bromopropionate as initiator followed by hydrolysis with methanolic KOH. Folic acid (FA) was connected with the PBuOx-COOH through polyethylene glycol (PEG) as spacer forming the FA-PEG-PBuOx. Thiol-modified betulinic acid (BA-SH) is conjugated to the side chains of FA-PEG-PBuOx by thio-ene reaction endowed the FA-PEG-PBuOx/BA with the acid-liable β-thiopropionate linkages. Additionally, the cellular uptake of the prodrug nanoparticles also showed vital potential for folate-receptor-positive HeLa cells. [ABSTRACT FROM AUTHOR]