Fig. 1

Illustration of the Bio-nFeR biochemical structure and fluorescence microscopic image of drug-containing micelles. a Schematic representation of micelles composed of phospholipids in the outer layer and fenretinide in the core. b Aqueous dispersions of Bio-nFeR and NCI-FeR formulations. (Left) Optical microscopy image of Bio-nFeR micelles in water. (Middle) Confocal image of Bio-nFeR (the same as in the left) showing the presence of autofluorescent fenretinide within micelles. (Right) Confocal image of NCI-FeR in water forming large aggregates of insoluble material (Images magnification is 60× and 10 μm scale bar is reported). c Confocal laser scanning images of Bio-nFeR micelles obtained by fenretinide ionization (left) and micelles obtained by the same procedure but without fenretinide ionization (Images magnification is 60× and 0.1 μm scale bar is reported). d Physico-chemical features of Bio-nFeR micelles. e Solubilization ability of Bio-nFeR towards fenretinide f) In vitro release of fenretinide from Bio-nFeR micelles in HCl solution (pH 1.2), phosphate buffer solution (pH 6.8) and phosphate buffer solution (pH 6.8) containing sodium taurocholate (3.0 mM)