Water-Soluble Fullerene (C60) Derivatives as Nonviral Gene-Delivery Vectors

A new class of water-soluble C60 transfecting agents has been prepared using Hirsch-Bingel chemistry and assessed for their ability to act as gene-delivery vectors in vitro. In an effort to elucidate the relationship between the hydrophobicity of the fullerene core, the hydrophilicity of the water-solubilizing groups, and the overall charge state of the C60 vectors in gene delivery and expression, several different C60 derivatives were synthesized to yield either positively charged, negatively charged, or neutral chemical functionalities under physiological conditions. These fullerene derivatives were then tested for their ability to transfect cells grown in culture with DNA carrying the green fluorescent protein (GFP) reporter gene. Statistically significant expression of GFP was observed for all forms of the C60 derivatives when used as DNA vectors and compared to the ability of naked DNA alone to transfect cells. However, efficient in vitro transfection was only achieved with the two positively charged C60 derivatives, namely, an octa-amino derivatized C60 and a dodeca-amino derivatized C60 vector. All C60 vectors showed an increase in toxicity in a dose-dependent manner. Increased levels of cellular toxicity were observed for positively charged C60 vectors relative to the negatively charged and neutral vectors. Structural analyses using dynamic light scattering and optical microscopy offered further insights into possible correlations between the various derivatized C60 compounds, the C60 vector/DNA complexes, their physical attributes (aggregation, charge) and their transfection efficiencies. Recently, similar Gd@C60-based compounds have demonstrated potential as advanced contrast agents for magnetic resonance imaging (MRI). Thus, the successful demonstration of intracellular DNA uptake, intracellular transport, and gene expression from DNA using C60 vectors suggests the possibility of developing analogous Gd@C60-based vectors to serve simultaneously as both therapeutic and diagnostic agents

Servant Leadership as a Factor of Social Entrepreneurship

Subject. The article focuses on two perspective directions of research in theoretical managerial thought. One of the directions is social entrepreneurship that exists in the field of entrepreneurship. The other one is servant leadership that describes an emerging concept in the field of leadership.Purpose. The purpose of the study is to formulate the tasks developing the management theory that is based on the symbiotic relationship between social entrepreneurship and servant leadership.Methodology. The scholars introduce new methodological approach to research and contribute to the conceptual development of management. The authors analyze and consolidate the interconnection and interpenetration of social entrepreneurship and servant leadership.Results. The article provides an overview of the main essence of social entrepreneurship and its general features. They distinguish social entrepreneurship from “traditional” one as well as from other cognate activities like “social activism”. Moreover, the work considers external and internal antecedents influencing the social entrepreneurship development. The following part of the article is devoted to the development of a new avenue in the leadership area. The authors describe fundamental changes in the management paradigm, in particular transformations in the leadership views. The article also addresses the major specifics of the servant leadership ideology and indicates the significance of servant leaders. Finally, the authors focus on the role of servant leadership in social entrepreneurship. They highlight the basic attributes that show the similar value orientations both for servant leader and social entrepreneur.Conclusions. In conclusion, the attempt to find interrelationships of certain directions from the classic management theory would be one of the contemporary trends in management theory development