The key role of the drug self-aggregation ability to obtain optimal nanocarriers based on aromatic-aromatic drug-polymer interactions

Concentration Dependent Single Chain Properties of Poly(sodium 4-styrenesulfonate) Subjected to Aromatic Interactions with Chlorpheniramine Maleate Studied by Diafiltration and Synchrotron-SAXS

“…Both complementary charged species bearing aromatic groups undergo secondary aromatic-aromatic interactions, additional to primary long-range electrostatic interactions, thus producing a reinforcement of the overall interaction. Contrary to the picture given by Manning’s counterion condensation theory [ 17 , 18 , 19 , 20 , 21 ], in which the territorial binding of counterions to polyelectrolyte chains occurs, aromatic counterions and polymeric aromatic groups produce site-specific binding, losing water molecules from their respective hydration spheres, as deduced by 1D and 2D 1 H-NMR spectroscopies [ 3 , 4 , 5 , 6 , 8 , 13 , 16 ]. Verification of the nuclear Overhauser effect allowed for the demonstration that the interacting species approach each other by less than 5 Å.…”

“…During the last decades, we have studied the interactions between aromatic polyelectrolytes, such as poly(sodium 4-styrenesulfonate) (PSS), and low molecular-weight aromatic species (LMWS) acting as counterions, among which we can find xanthene dyes [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ], redox-active tetrazolium salts [ 8 , 9 , 10 , 11 ], and different drugs [ 12 , 13 , 14 , 15 , 16 ]. Both complementary charged species bearing aromatic groups undergo secondary aromatic-aromatic interactions, additional to primary long-range electrostatic interactions, thus producing a reinforcement of the overall interaction.…”

“…Drug vehiculization and controlled release in matrices and nanoparticles based on aromatic-aromatic interactions have also been developed [ 15 , 16 , 23 ]. Importantly, outstanding drug loading of around 50% has been achieved, since the drug acts both as a bioactive molecule carried by the nanoparticle and as a main constituent of the carrier [ 15 , 16 ].…”

“…Drug vehiculization and controlled release in matrices and nanoparticles based on aromatic-aromatic interactions have also been developed [ 15 , 16 , 23 ]. Importantly, outstanding drug loading of around 50% has been achieved, since the drug acts both as a bioactive molecule carried by the nanoparticle and as a main constituent of the carrier [ 15 , 16 ]. The mechanism for nanocarrier formation involving the dual function of the drug has been rationalized as the consequence of ion pair formation between the charged aromatic drug and the complementary charged polymeric aromatic residues through short-range aromatic-aromatic interactions.…”

“…The mechanism for nanocarrier formation involving the dual function of the drug has been rationalized as the consequence of ion pair formation between the charged aromatic drug and the complementary charged polymeric aromatic residues through short-range aromatic-aromatic interactions. The occurrence of aromatic-aromatic interactions between the drug chlorpheniramine maleate (CPM) and the polyelectrolyte PSS has been reported in this context [ 12 , 13 , 14 , 16 ]. It was found that the extent of binding and the aggregation state of the complexes depend on the absolute and the relative concentration of the reactants.…”