Uncommon Structures of Oppositely Charged Hyaluronan/Surfactant Assemblies under Physiological Conditions.

Uncommon Structures of Oppositely Charged Hyaluronan/Surfactant Assemblies under Physiological Conditions.
Biomacromolecules. 2020 Aug 14;:
Authors: Buchold P, Ram-On M, Talmon Y, Hoffmann I, Schweins R, Gradzielski M
Abstract
Self-assembled aggregates formed by semidilute polyanion hyaluronan (hyaluronic acid, HA) and an oppositely charged surfactant tetradecyltrimethylammonium bromide (TTAB) in an aqueous phosphate-buffered saline (PBS) solution have been studied via light scattering (LS), small-angle neutron scattering (SANS), and cryogenic transmission electron microscopy (cryo-TEM). The addition of 0-20 mM TTAB to a 27.7 mM (monomer, 1 wt %) HA solution (597 kDa) in PBS buffer leads to soluble complexes until phase separation occurs near charge equilibrium (>20 mM TTAB). While the viscosity remains rather constant, already small amounts of added TTAB lead to the formation of large globular superstructures, which are built in a hierarchical fashion from a locally threadlike structural arrangement of TTA micelles along the stiff HA chains, within the little changed HA network. These globular domains have radii of 60-100 nm and contain 500-700 TTA micelles, which means that they are very "fluffy" and composed of about 99% water. They do not grow in size or number upon further TTAB addition, but, instead, the additional TTA micelles form further threadlike complexes outside of the big globular domains. Such a type of polyelectrol...

Source: Biomacromolecules - August 13, 2020 Category: Biochemistry Authors: Buchold P, Ram-On M, Talmon Y, Hoffmann I, Schweins R, Gradzielski M Tags: Biomacromolecules Source Type: research