An approach for the design of functionalized cyclic peptides is established for use in 3D cell culture and in cell targeting. Sequential orthogonal click reactions, specifically a photoinitiated ...thiol-ene and strain promoted azide-alkyne cycloaddition, were utilized for peptide cyclization and conjugation relevant for biomaterial and biomedical applications, respectively.
An approach for the design of functionalized cyclic peptides is established for use in 3D cell culture and in cell targeting.
Healable polymer systems Hayes, Wayne; Greenland, Barnaby W
2013., 2013, 2013-03-13, Letnik:
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eBook
Written by leading experts, the book provides polymer scientists with a compact and readily accessible source of reference for healable polymer systems.
This chapter outlines several critical aspects of the design of polymer networks containing reversible covalent cross-links for material healing applications. Polymer network architecture and ...reversible cross-link type are identified as the principle considerations in covalent adaptable network design, as they ultimately dictate how efficiently the material will heal or relax on a macroscopic length-scale. Additionally, several reversible addition- and exchange-type covalent chemistries suitable as cross-links in covalent adaptable networks, as well as strategies to trigger healing reactions, are highlighted. Finally, the dynamic properties of these materials is briefly discussed, highlighting the distinguishing characteristics in comparison with traditional thermoplastics and thermosets.
The objective of the dissertation is to investigate the structural and dynamical behavior of aqueous poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock surfactant dispersions, ...commercially known as Pluronics™, by studying the Brownian or thermal motion of embedded tracer probe particles. Recent advances in the understanding of diffusive light transport in highly scattering media seeded a novel dynamic light scattering technique in the multiple scattering limit known as diffusing wave spectroscopy (DWS). This technique allows for the determination of probe motion at frequencies greater than 1 MHz and at a spatial resolution of several angstroms. Thus, DWS provides unique access to early thermal relaxation modes in complex fluids that are the proposed origin of viscoelastic behavior observed on a macroscopic level. In general, Pluronic-type macromolecular surfactants associate into spherical micelles when dispersed in aqueous solution, leading to complex structures and rich dynamic behavior. In the first part of the dissertation, we demonstrate the utility of DWS microrheology by investigating the short-time dynamics of aqueous Pluronic L64 (EO)13(PO)30(EO)13 solutions, revealing a temperature independent high frequency viscosity above the micellization temperature. The dynamics at high temperatures are dominated by an apparent attractive inter-micellar potential, consistent with our inverse osmotic pressure measurements. We directly confirm the presence of a short-lived elastic gel at high temperatures, which previously could only be inferred by extrapolating traditional mechanical rheometry measurements. We attribute the existence of this short-lived elastic gel to sample spanning clusters indicating the crossing of a dynamic percolation threshold. In the second part of this dissertation, we utilize a high-pressure scattering cell to examine the pressure-temperature phase space of aqueous Pluronic P85 (EO)25(PO)40(EO)25 solutions. We demonstrate that subtle changes in water by densification via increased hydrostatic pressure, by increasing thermal energy, or even by isotopic substitution, lead to discernable large-scale effects in aqueous P85 Pluronic samples. More generally, we demonstrate the utility of DWS colloidal sphere thermal motion studies to explore complex fluids in high pressure and temperature environments, allowing for the construction of phase diagrams based on dynamical pathways.
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