Hydration of diblock copolymer micelles: Effects of hydrophobicity and co-solvent.

Diblock polymer micelles dispersed in an aqueous environment are being actively investigated for various applications, but there is only a qualitative understanding of the effect of the chemical structure on the micelle hydration and water dynamics as these properties are difficult to assess experimentally. Using all-atom molecular dynamics simulations, we investigate aqueous solutions of three comparable in size diblock copolymer micelles with core-forming blocks of different hydrophobicity: polybutadiene (PB), polycaprolactone (PCL), and polytetrahydrofuran (pTHF) with the same hydrophilic block, polyethylene oxide (PEO). We found that core-block hydrophobicity and ability to form hydrogen bonds with water strongly affect the water dynamics near the core: water molecules spend considerably less time in contact with the PB block than with PCL and pTHF blocks.

Effect of Peptide Sequence on the LCST-Like Transition of Elastin-Like Peptides and Elastin-Like Peptide-Collagen-Like Peptide Conjugates: Simulations and Experiments.

Elastin-like polypeptides (ELPs) are thermoresponsive biopolymers that undergo an LCST-like phase transition in aqueous solutions. The temperature of this LCST-like transition, T , can be tuned by varying the number of repeat units in the ELP, sequence and composition of the repeat units, the solution conditions, and via conjugation to other biomacromolecules. In this study, we show how and why the choice of guest (X) residue in the VPGXG pentad repeat tunes the T of short ELPs, (VPGXG), in the free state and when conjugated to collagen-like peptides (CLPs).

Co-micellization behavior of triblock copolymers in the presence of hydrophobic drug molecules: A simulation study.

Dissipative particle dynamics simulation of bead-spring chains is applied to study co-micellization, micellar and drug loading properties of binary triblock copolymer systems to seek a better understanding on selection and utilization of polymer mixtures to improve the drug encapsulation efficiency and loading capacity. Co-micellization is found to still occur in the presence of drug; pure and mixed micelles coexist with some devoid of any drug due to their significantly lower aggregation numbers. The drug encapsulation enlarges the micelle cores, and may induce a morphology transition from spherical to ellipsoidal or rod-like micelles.

Co-micellization behavior in poloxamers: dissipative particle dynamics study.

Dissipative particle dynamics simulations are applied to investigate co-micellization behavior for binary mixtures of Poloxamers in dilute aqueous solution. In view of block length similarity/dissimilarity, four representative mixture cases are considered: F127/P123, F127/P105, P123/P84, and F127/L64. With appropriate interaction parameters, the simulations enable us to examine the formation of micelles, their types, size, shape, and composition.