• Home
  • Search Results
  • Aggregation of poly(acrylic acid)-containing elastin-mimetic copolymers.

Aggregation of poly(acrylic acid)-containing elastin-mimetic copolymers.

Soft matter (2015-01-23)
Bradford A Paik, Marco A Blanco, Xinqiao Jia, Christopher J Roberts, Kristi L Kiick
ABSTRACT

Polymer-peptide conjugates were produced via the copper-catalyzed azide-alkyne cycloaddition of poly(tert-butyl acrylate) (PtBA) and elastin-like peptides. An azide-functionalized polymer was produced via atom transfer radical polymerization (ATRP) followed by conversion of bromine end groups to azide groups. Subsequent reaction of the polymer with a bis-alkyne-functionalized, elastin-like peptide proceeded with high efficiency, yielding di- and tri-block conjugates, which after deprotection, yielded poly(acrylic acid) (PAA)-based diblock and triblock copolymers. These conjugates were solubilized in dimethyl formamide, and addition of phosphate buffered saline (PBS) induced aggregation. The presence of polydisperse spherical aggregates was confirmed by dynamic light scattering and transmission electron microscopy. Additionally, a coarse-grained molecular model was designed to reasonably capture inter- and intramolecular interactions for the conjugates and its precursors. This model was used to assess the effect of the different interacting molecular forces on the conformational thermodynamic stability of the copolymers. Our results indicated that the PAA's ability to hydrogen-bond with both itself and the peptide is the main interaction for stabilizing the diblocks and triblocks and driving their self-assembly, while interactions between peptides are suggested to play only a minor role on the conformational and thermodynamic stability of the conjugates.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
N,N-Dimethylformamide, suitable for HPLC, ≥99.9%
Sigma-Aldrich
Methanol, HPLC Plus, ≥99.9%, poly-coated bottles
Supelco
Methanol, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Tetrahydrofuran, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Dimethylformamide, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Residual Solvent - Toluene, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Sodium azide, BioXtra
Sigma-Aldrich
Sodium azide, ReagentPlus®, ≥99.5%
Sigma-Aldrich
N,N-Dimethylformamide, for molecular biology, ≥99%
Sigma-Aldrich
Dimethyl sulfoxide-d6, "Special HOH", ≥99.9 atom % D
Sigma-Aldrich
Chloroform-d, 99.8 atom % D
Sigma-Aldrich
Chloroform-d, 99.8 atom % D, contains 1 % (v/v) TMS
Sigma-Aldrich
Chloroform-d, 99.8 atom % D, contains 0.1 % (v/v) TMS
Sigma-Aldrich
Chloroform-d, ≥99.8 atom % D, contains 0.5 wt. % silver foil as stabilizer, 0.03 % (v/v) TMS
Sigma-Aldrich
Dimethyl sulfoxide-d6, "100%", 99.96 atom % D, contains 0.03 % (v/v) TMS
Sigma-Aldrich
Methanol, anhydrous, 99.8%
Sigma-Aldrich
Chloroform-d, ≥99.8 atom % D, contains 0.5 wt. % silver foil as stabilizer
Sigma-Aldrich
Chloroform-d, 99.8 atom % D, contains 0.03 % (v/v) TMS
Sigma-Aldrich
Tetrahydrofuran, anhydrous, ≥99.9%, inhibitor-free
Sigma-Aldrich
Sodium azide, BioUltra, ≥99.5% (T)
Sigma-Aldrich
Dimethyl sulfoxide-d6, 99.9 atom % D, contains 1 % (v/v) TMS
Sigma-Aldrich
Chloroform-d, ≥99.8 atom % D, anhydrous
Sigma-Aldrich
Chloroform-d, 99.8 atom % D, contains 0.05 % (v/v) TMS
Sigma-Aldrich
Chloroform-d, "100%", 99.96 atom % D
Sigma-Aldrich
Dimethyl sulfoxide-d6, "100%", 99.96 atom % D
Sigma-Aldrich
Dimethyl sulfoxide-d6, anhydrous, 99.9 atom % D
Sigma-Aldrich
Tetrahydrofuran, suitable for HPLC, ≥99.9%, inhibitor-free
Sigma-Aldrich
Chloroform-d, "100%", 99.96 atom % D, contains 0.5 wt. % silver wire as stabilizer
Sigma-Aldrich
Methanol, suitable for HPLC, gradient grade, 99.93%
Sigma-Aldrich
Chloroform-d, "100%", 99.96 atom % D, contains 0.03 % (v/v) TMS