Responsive hydrophobically associating polymers: a review of structure and properties

Effect of Polymer Composition and pH on Membrane Solubilization by Styrene-Maleic Acid Copolymers

“…minimize energetically unfavorable styrene-water contacts. Indeed, in previous studies it was found that at low pH the 1:1 SMA variant collapses into a globular conformation that contains hydrophobic domains while the polymer is still water soluble (23). Such hydrophobic domains may occur within one polymer chain, but they also may be formed as a consequence of intermolecular interactions, when the polymers are present in aggregates containing multiple polymer chains termed ''polymeric micelles'' (24,25), as will be discussed later.…”

The Styrene-Maleic Acid Copolymer: A Versatile Tool in Membrane Research

“…This pH dependence has major consequences for the conformation and solubility of SMA, as has been described for several other amphipathic polymers (Henry et al 2006;Tonge and Tighe 2001). In the case of SMA, at neutral and high pH, electrostatic repulsions between the carboxylate groups dominate the hydrophobic effect and the polymer adopts a random coil conformation that dissolves relatively easily in aqueous solution.…”

“…A decrease of the pH well below the lower pK a of the maleic acid unit will lead to complete protonation of SMA. Charge repulsion is then lost and the hydrophobic effect causes SMA to adopt a globular conformation and eventually to precipitate as aggregates (Sugai and Ebert 1985;Sugai et al 1982;Tonge and Tighe 2001). The exact pH range that mediates this structural transition will depend on the composition of the polymer and also on the ionic strength in the solution.…”

Polymer–lipid interactions: Biomimetic self-assembly behaviour and surface properties of poly(styrene-alt-maleic acid) with diacylphosphatidylcholines

“…The challenge in producing replacements for these fluids in treating lubricity deficiency diseases such as dry eye, respiratory distress syndrome (RDS) and arthritis is not replacing the phospholipid, which is readily available in synthetic form, but in replacing the apoprotein component. In this paper we investigate the self-assembly behaviour and surface properties of the poly(styrene-alt-maleic acid) -diacylphosphatidylcholine system that was initially identified in these laboratories as a potential reactive functional substitute [1,2].…”

“…For that reason, analogues have been developed to mimic its biophysical properties instead of its chemistry. An effective lung surfactant must have at least three fundamental biophysical properties: (1) rapid adsorption to the air-water interface, (2) the ability to reach near-zero surface tension upon film compression, and (3) the ability to respread upon multiple compressions and expansions of surface area with minimal loss of surfactant into the subphase [6]. Non-natural analogues of SP-B such as amphiphilic peptides and peptoids have been previously studied [7,8].…”