Lipid-based drug carriers, such as liposomes or drug/lipid complexes, have been extensively investigated in a large number of therapeutic protocols such as gene therapy, drug delivery, drug targeting and antibacterial treatments, in preclinical and clinical trials. Many formulations composed of natural and/or synthetic amphiphiles have been studied. Many synthetic lipids and surfactants have been designed and tested in order to improve liposomes and lipid complexes performances, such as fusion with cellular membrane, cellular uptake, target selectivity, transfection efficiency, low toxicity. Among these, gemini surfactants have been shown to be highly effective in delivering genetic material to cells, and also have been shown promising as synthetic additives in liposome formulations for drug delivery. The encouraging results obtained in gene therapy have given impulse to chemist creativity: an extensive selection of pH sensitive, sugar-, aminoacid- , and peptide-based gemini surfactants have been developed, many of which have shown good biological features. This review focuses on recent progress in gemini surfactant based formulations and their applications in different therapeutic protocols.

Scavengers of hypochlorite (XOCI) could have beneficial effects in diseases in which this oxidant plays a pathogenic role. It has been reported that ferulic acid and chlorogenic acid, the quinic ester of caffeic acid, are good hypochlorite scavengers, but a systematic evaluation of the naturally occurring hydroxycinnamic acids (HCAs), which these substances belong to, has not been performed yet. Thus, in this work we studied, by two different in-vitro methods, the antioxidant activity of five HCAs: p-coumaric acid, ferulic acid, sinapinic acid, caffeic acid and chlorogenic acid. The methods applied in this study were based on the oxidation of human serum albumin (HSA) by XOCI, a new microplate method based on the measurement of chloramines and a previously described carbonyl assay. Firstly, lysine-derived chloramines, in the presence or absence of the HCAs, were detected using 5-thio-2-nitrobenzoic acid (TNB), measuring the absorbance at 415nm by a microplate reader. To remove excess XOCI, Trolox, a known XOCI scavenger, was added before TNB. Secondly, lysine-derived carbonyls, in the presence or absence of the HCAs, were detected by using 2,4-dinitro-phenylhydrazine. Hydroxycinnamic acids appeared active (caffeic≥sinapinic>chlorogenic≅ferulic>p-coumaric acid) by both methods, suggesting possible pharmacological applications for these compounds, which are present at high concentrations in the plant kingdom.