Synthesis of poly(ethylene glycol)-block-poly(ethylenimine) possessing an acetal group at the PEG end

Citation
Y. Akiyama et al., Synthesis of poly(ethylene glycol)-block-poly(ethylenimine) possessing an acetal group at the PEG end, MACROMOLEC, 33(16), 2000, pp. 5841-5845
Citations number
40
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
MACROMOLECULES
ISSN journal
0024-9297 → ACNP
Volume
33
Issue
16
Year of publication
2000
Pages
5841 - 5845
Database
ISI
SICI code
0024-9297(20000808)33:16<5841:SOPGPA>2.0.ZU;2-B
Abstract
A new linear block copolymer of poly(ethylene glycol) (PEG) and poly(ethyle nimine) (PEI) possessing an acetal group at the PEG chain end was prepared by a heterotelechelic PEG macroinitiator technique. Heterotelechelic PEG wi th an acetal group at one end and a methanesulfonic group at the other end (acetal-PEG-SO2CH3) was synthesized by the anionic ring-opening polymerizat ion of ethylene oxide (EO) initiated with potassium 3,3-diethoxypropanolate (PDP), followed by end-capping with methanesulfonyl chloride. Acetal-PEG-S O2CH3 was then used as a macroinitiator for the cationic ring-opening polym erization of 2-methyl-2-oxazoline (Oz) to form the block copolymer, acetal- PEG-POz. The block efficiency attained almost 100%, allowing to control the molecular weight of the POz segment by the initial monomer/initiator ratio . Alkaline hydrolysis of the repeating acetyl groups in the POz segment gav e the completely deacylated block copolymer retaining the acetal group at t he PEG chain end. The acetal-PEG-poly(ethylenimine) block copolymer thus ob tained may have a potential utility as targetable DNA carrier in the field of gene delivery.