In situ growth of a thermoresponsive polymer from a genetically engineered elastin-like polypeptide

TitleIn situ growth of a thermoresponsive polymer from a genetically engineered elastin-like polypeptide
Publication TypeJournal Article
Year of Publication2011
AuthorsGao, W, Xu, D, Lim, DW, Craig, SL, Chilkoti, A
JournalPolymer Chemistry
Volume2
Issue7
Pagination1561
Date Published2011
ISSN1759-9962
Abstract

We report the in situ growth of a thermoresponsive dumbbell-like polymer conjugate of a genetically engineered triblock elastin-like polypeptide (tELP). Atom transfer radical polymerization (ATRP) was used to directly grow a PEG-like polymer selectively from the first and third blocks of the tELP to form a poly(oligo(ethylene glycol) methyl ether methacrylate) (poly(OEGMA)) brush conjugate with quantitative yield. We found that in situ growth of poly(OEGMA) from tELP significantly changed the inverse phase transition and rheological behaviors of tELP. Dynamic light scattering (DLS) and turbidity measurements as a function of temperature showed that the inverse phase transition behavior of the conjugate was not determined by the tELP but by poly(OEGMA). Oscillatory rheological measurements indicated that the conjugate started to form a physical hydrogel at a temperature of 55 °C. In vitro enzymatic degradation studies showed that the conjugate could be degraded by collagenase. These results suggest that this class of conjugates may be potentially useful as an injectable, thermoresponsive drug carrier for local drug delivery and as a scaffold for tissue engineering.

DOI10.1039/c1py00074h
Short TitlePolym. Chem.