Solubilization and catalytic behavior of micellar system based on gemini surfactant with hydroxyalkylated head group

Gemini and Bicephalous Surfactants: A Review on Their Synthesis, Micelle Formation, and Uses

The use of surfactants in polymerization reactions is particularly important, mainly in emulsion polymerizations. Further, micelles from biocompatible surfactants find use in pharmaceutical dosage forms. This paper reviews recent developments in the synthesis of novel gemini and bicephalous surfactants, micelle formation, and their applications in polymer and nanoparticle synthesis, oil recovery, catalysis, corrosion, protein binding, and biomedical area, particularly in drug delivery.

Cationic Surfactants: Self-Assembly, Structure-Activity Correlation and Their Biological Applications

The development of biotechnological protocols based on cationic surfactants is a modern trend focusing on the fabrication of antimicrobial and bioimaging agents, supramolecular catalysts, stabilizers of nanoparticles, and especially drug and gene nanocarriers. The main emphasis given to the design of novel ecologically friendly and biocompatible cationic surfactants makes it possible to avoid the drawbacks of nanoformulations preventing their entry to clinical trials. To solve the problem of toxicity various ways are proposed, including the use of mixed composition with nontoxic nonionic surfactants and/or hydrotropic agents, design of amphiphilic compounds bearing natural or cleavable fragments. Essential advantages of cationic surfactants are the structural diversity of their head groups allowing of chemical modification and introduction of desirable moiety to answer the green chemistry criteria. The latter can be exemplified by the design of novel families of ecological friendly cleavable surfactants, with improved biodegradability, amphiphiles with natural fragments, and geminis with low aggregation threshold. Importantly, the development of amphiphilic nanocarriers for drug delivery allows understanding the correlation between the chemical structure of surfactants, their aggregation behavior, and their functional activity. This review focuses on several aspects related to the synthesis of innovative cationic surfactants and their broad biological applications including antimicrobial activity, solubilization of hydrophobic drugs, complexation with DNA, and catalytic effect toward important biochemical reaction.

Structural, biocomplexation and gene delivery properties of hydroxyethylated gemini surfactants with varied spacer length

Gemini surfactants with hexadecyl tails and hydroxyethylated head groups bridged with tetramethylene (G4), hexamethylene (G6) and dodecamethylene (G12) spacers were shown to self-assemble at the lower critical micelle concentration compared to their conventional m-s-m analogs. The lipoplex formation and the plasmid DNA transfer into different kinds of host cells were studied. In the case of eukaryotic cells, high transfection efficacy has been demonstrated for DNA-gemini complexes, which increased as follows: G6<G4<G12. Different activity series, i.e., G6>G4>G12 has been obtained in the case of transformation of bacterial cells with plasmid DNA-gemini complexes, mediated by electroporation technique. Solely G6 shows transformation efficacy exceeding the control result (uncomplexed DNA), while the inhibitory effect occurs for G4 and G12. Analysis of physico-chemical features of single surfactants and lipoplexes shows that compaction and condensation effects change as follows: G6<G4 ≤ G12, i.e., agree with the order of transfection efficacy, which is supported by membrane tropic properties of G12. On the other hand, gel retardation assay and docking study testify low electrostatic affinity in G12/DNA pair, thereby indicating that hydrophobic effect probably plays important role in the lipoplex formation. Two factors are assumed to be responsible for the inhibition effect of gemini in the case of transformation of bacterial cells. They are (i) an unfavorable influence of cationic surfactants on the electroporation procedure due to depressing the electrophoretic effect; and (ii) antibacterial activity of cationic surfactants that may cause the disruption of integrity of cell membranes.