Self-assembled quaternary ammonium surfactants for pharmaceuticals and biotechnology

Abstract Self-assembled quaternary ammonium surfactants (QAS), produced from supramolecular amphiphilic compounds, are being tailored for bioengineering applications. In comparison to their neutral counterparts, quaternary ammonium compounds (QACs) demonstrate enhanced capacity for drug solubilization, which is particularly useful for the loading of lipophilic compounds. This approach may result in improved drug loading capacity and encapsulation efficiency. Several factors (e.g., structure of surfactants and solute, aggregation number, morphology of aggregates, ionic force, and temperature) influence the capacity of QACs to be used as new drug delivery systems. Particular emphasis will be given to the Gemini QAS, evidencing their properties, comparing to monomer counterparts, and highlighting their particular characteristics (e.g., low critical micellar concentration, antimicrobial activity) that make them surfactants of choice for target-drug delivery. This review discusses the properties and applications of self-assembled QAS for the delivery of peptides and proteins, genes and antimicrobials.