Cylindrical Polymer Brushes with Elastin-Like Polypeptide Side Chains

Abstract

Monodisperse high molar mass elastin-like polypeptide macromonomers comprising 20 pentasequences (M = 8332 g/mol) were radically polymerized to high degrees of polymerization P w = 590. Polymerization was conducted in water well above the lower phase transition temperature, i.e., in the phase separated regime. The resulting polymers adopt a cylindrical shape as demonstrated by AFM pictures of solutions spin-cast on mica. The directional persistence of the cylindrical brushes was determined by static light scattering to Kuhn statistical segments lengths l k = 120 nm at 5 mM aqueous NaCl solution which decreased to l k = 54 nm at 0.65 M NaCl. Upon polymerization the phase transition temperature drops significantly and the transition interval becomes sharper. The change of the hydrodynamic radius of the cylindrical brushes was monitored by dynamic light scattering as a function of temperature and revealed a continuous decrease from 20 to 36 °C, above of which aggregates of several hundred nm in size start to form prior to phase separation.

Chemoenzymatic synthesis of polypeptides consisting of periodic di- and tri-peptide motifs similar to elastin

“…This behavior was also observed for artificial elastin analogues. [32][33][34] When the sample was cooled from 80 to 10°C, the unordered content increased with reversible decrease in the helical content. This clearly shows that poly(ValProGly-co-ValGly) undergoes a structural transition similar to natural elastin at elevated temperatures.…”

Peptide-Based Polymer Therapeutics

“…Brush-like polymers can be designed to contain flexible side-chain polymers, such as poly(methyl methacrylate), poly(styrene), elastin-like polypeptides, and PEG [204][205][206].…”

Controlled release from recombinant polymers

“…In one case, cylindrical micelles were formed by radical polymerization of ELPs which may be advantageous in drug delivery due to the large number of potential sites for functionalization. [55] Combining the monodispersity and functional strengths of recombinant polymers with chemical polymerization can yield the design and development of a wide array of organized structures. Similar to ELP hybrids, the synthesis of multi-armed ELP constructs has been achieved that consists of an ELP domain fused to a fold-on domain that links three individual polymer strands.…”