Biocompatible surfactants from renewable hydrophiles

Significant advances made by the authors in the field of cationic surfactants derived from arginine and lysine hydrophilic sources of different structure are reviewed. Linear, gemini and glycerolipid-like structures with polar groups consisting of Arg or Lys amino acids are described. Our multidisciplinary approach includes design, synthesis, adsorption at interfaces and self-assembly behavior, antimicrobial activity, and studies of biocompatibility including ecotoxicity, biodegradability and irritation effects. Considering the green chemistry principles, the synthesis contemplates the preparation of more efficient and safer surfactants using renewable raw materials for the synthesis of surfactants: proteins, peptides, amino acids and triacylglycerols, using biocatalysis as condensating methodology, and designing for biodegradation. Also in order to increase the efficiency of these compounds, a complete characterization including self-assembly, ecotoxicity, biodegradability, and studies of mechanisms of toxicity has been carried out. The structure of the surfactant molecule affects micellization and not the nature of the polar head (Arg or Lys). The critical micelle concentrations of the gemini surfactants are three orders of magnitude lower than the linear ones for the same alkyl chain length. The presence of a cationic charge in the amino acid provides antimicrobial activity to these compounds.