Universal concept for the implementation of a single cleavable unit at tunable position in functional poly(ethylene glycol)s.

Poly(ethylene glycol) (PEG) with acid-sensitive moieties gained attention particularly for various biomedical applications, such as the covalent attachment of PEG (PEGylation) to protein therapeutics, the synthesis of stealth liposomes, and polymeric carriers for low-molecular-weight drugs. Cleavable PEGs are favored over their inert analogues because of superior pharmacodynamic and/or pharmacokinetic properties of their formulations. However, synthetic routes to acetal-containing PEGs published up to date either require enormous efforts or result in ill-defined materials with a lack of control over the molecular weight.

Catechol-initiated polyethers: multifunctional hydrophilic ligands for PEGylation and functionalization of metal oxide nanoparticles.

Bifunctional CA-PEG (catechol-poly(ethylene glycol)) and multifunctional CA-PEG-PGA/PEVGE (poly(glycidyl amine)/poly(ethylene glycol vinyl glycidyl ether)) ligands for the functionalization and solubilization of nanoparticles are introduced. Tunable polymers with polydispersities <1.25 and molecular weights in the range 500-7700 g mol(-1) containing a catechol moiety for conjugation to metal oxide nanoparticles were prepared.

Branched Acid-Degradable, Biocompatible Polyether Copolymers via Anionic Ring-Opening Polymerization Using an Epoxide Inimer.

The introduction of acid-degradable acetal moieties into a hyperbranched polyether backbone has been achieved by the design of a novel epoxide-based degradable inimer. This new monomer, namely, 1-(glycidyloxy)ethyl ethylene glycol ether (GEGE), has been copolymerized in the anionic ring-opening polymerization (AROP) with ethylene oxide (EO) or glycidol (G), respectively, yielding branched polyethers, that is, P(EO--GEGE) and P(G--GEGE), that possess an adjustable amount of acid-cleavable acetal units. In addition, a novel class of multiarm star copolymers P(G--GEGE--EO) with acid-labile polyether core and PEG side chains was synthesized by using the P(G--GEGE) copolymers as multifunctional macroinitiators for AROP of EO.