Synthesis, Self-Assembly and In Vitro Cellular Uptake Kinetics of Nanosized Drug Carriers Based on Aggregates of Amphiphilic Oligomers of N-Vinyl-2-pyrrolidone

Development of nanocarrier-based drug delivery systems is a major breakthrough in pharmacology, promising targeted delivery and reduction in drug toxicity. On the cellular level, encapsulation of a drug substantially affects the endocytic processes due to nanocarrier–membrane interaction. In this study we synthesized and characterized nanocarriers assembled from amphiphilic oligomers of N-vinyl-2-pyrrolidone with a terminal thiooctadecyl group (PVP-OD). It was found that the dissolution free energy of PVP-OD depends linearly on the molecular mass of its hydrophilic part up to [Formula: see text] = 2 × 10(4), leading to an exponential dependence of critical aggregation concentration (CAC) on the molar mass. A model hydrophobic compound (DiI dye) was loaded into the nanocarriers and exhibited slow release into the aqueous phase on a scale of 18 h. Cellular uptake of the loaded nanocarriers and that of free DiI were compared in vitro using glioblastoma (U87) and fibroblast (CRL2429) cells. While the uptake of both DiI/PVP-OD nanocarriers and free DiI was inhibited by dynasore, indicating a dynamin-dependent endocytic pathway as a major mechanism, a decrease in the uptake rate of free DiI was observed in the presence of wortmannin. This suggests that while macropinocytosis plays a role in the uptake of low-molecular components, this pathway might be circumvented by incorporation of DiI into nanocarriers

Economic Ideas and Institutional Change: Evidence from Soviet Economic Discourse 1987-1991

In recent years, institutional and evolutionary economists have become increasingly aware that ideas play an important role in economic development. In the current literature, the problem is usually elaborated upon in purely theoretical terms. In the present paper it is argued that ideas are always also shaped by historical and cultural factors. Due to this historical and cultural specificity theoretical research must be supplemented by historical case studies. The paper analyses the shift in ideas that took place in Soviet economic thought between 1987 and 1991. This case study, it is argued, may contribute to our understanding of the links between ideas and institutions. More specifically, it sheds new light on the issue of whether the evolution of economic ideas is pathdependent, so that they change only incrementally, or whether their development takes place in a discontinuous way that can best be compared with revolutions

Directional Control of the Structural Adsorption Properties of Clays by Magnetite Modification

This article presents the results of the study on the effect of nanomagnetite modification on textural characteristics of clay matrices, adsorption properties, and parameters of the spent sorbents separation. The nitrogen adsorption-desorption method has shown that the obtained magnetic nanocomposite sorbents have large specific surface areas (in 1.2–2 times more) than the initial clays due to the formation of the secondary porous structure on the surface and in macropores of clay matrices. The best adsorption properties with respect to dyes belong to magnetic sorbents with nanomagnetite content of 7 wt.%. The additional modification of the third phase of graphene-like molybdenum disulphide into magnetic sorbents leads to the significant increase in the sorption capacity of both cationic (up to 1100 mg/g) and anionic (up to 1830 mg/g) dyes. The conducted investigations of the total acidity and acid-base sites on the surface of clay, magnetite-modified clay, and molybdenum disulfide-modified magnetic sorbent indicate the significant influence of the Lewis base cites on the adsorption properties of these materials