Hydrogen-Bonded Multilayers for the Release of Polyelectrolyte Nanotubes in Biocompatible Conditions

The growth and disaggregation of hydrogen-bonded layer-by-layer (LbL) multilayers based on poly(methacrylic acid) (PMAA) and poly(N-vinylcaprolactam) (PVCL) are studied depending on pH, NaCl concentration, and PVCL molar mass. Whereas multilayer growth is essentially insensitive to salt and PVCL molar mass, the critical pH for disaggregation strongly depends on salt concentration. The PMAA/PVCL multilayers are then used as sacrificial compartments for the release of LbL nanostructures in biocompatible close-to-neutral 0.15 M NaCl aqueous conditions. We particularly demonstrate the liberation of LbL nanotubes grown inside the nanopores of templating polymer membranes without having to dissolve the membrane template in nonbiocompatible organic solvents and show that the amount of released nanotubes is close to the amount of noncrossing nanopores in the membrane.