Lipoic acid nanoforms based on phosphatidylcholine: production and characteristics.

We describe the dynamics of lipoic acid (LA) alone, incorporated in liposomes and as a part of nanoemulsions. Mass spectrometry shows that LA in water forms aggregates of two or three molecules in the form of a negatively charged ion and a neutral molecule. Phosphatidylcholine (PC)-based nanoforms of LA as liposomes and nanoemulsions with a particle size equal to 145 nm are characterized by a high degree of incorporation of LA into the nanoparticles and long-term stability during storage at room temperature. Dynamic light scattering (DLS) gives the polydispersity index of the nanoforms (> 0.3), characterizing the homogeneity of the obtained nanodispersions. We found that such emulsions can significantly (5 ×) increase the concentration of LA in the aqueous phase (5-7 mg/mL) when compared with an aqueous solution of LA (1 mg/mL) and by 40% when compared with PC liposomes (4 mg/mL). Moreover, the inclusion of LA in liposomes and nanoemulsions from PC did not change the neutral ζ-potential characteristic of PC nanoforms. CryoTEM established that the structural organization of the liposomes practically did not differ from nanoemulsions and both nanoforms contained both multilayer and single-layer vesicles. When studying the release kinetics of LA from phosphatidylcholine nanoforms, we found that at 22 h, 45-55% of LA was released from nanoparticles, but that at the initial stage of the process LA was slowly released from the nanoemulsions and rapidly from the liposomes. Conductance measurements indicate that LA delivered in all the three forms increase membrane permeability, though this result is most marked with the LA in PC liposomes.

[Non-esterified fatty acids of blood serum in type 1 diabetic women during late pregnancy].

Using gas chromatography a comparative study of the range and content of individual non-esterified fatty acids in serum of patients with diabetes mellitus type 1 in the third trimester of pregnancy, and healthy pregnant and non-pregnant women has been carried out. In groups of pregnant women there was activation of lipid metabolism, confirmed by corresponding changes in serum biochemical parameters, as well as in the content of non-esterified fatty acids. Intergroup differences in the non-esterified fatty acids were not found. However, there were significant differences between the examined groups in the quantitative content of non-esterified fatty acids.