RESUMEN
It is well-known that aqueous dispersions of phospholipids spontaneously assemble into bilayer structures. These structures have numerous applications across chemistry and materials science and form the fundamental structural unit of the biological membrane. The particular environment of the lipid bilayer, with a water-poor low dielectric core surrounded by a more polar and better hydrated interfacial region, gives the membrane particular biophysical and physicochemical properties and presents a unique environment for chemical reactions to occur. Many different types of molecule spanning a range of sizes, from dissolved gases through small organics to proteins, are able to interact with membranes and promote chemical changes to lipids that subsequently affect the physicochemical properties of the bilayer. This Review describes the chemical reactivity exhibited by lipids in their membrane form, with an emphasis on conditions where the lipids are well hydrated in the form of bilayers. Key topics include the following: lytic reactions of glyceryl esters, including hydrolysis, aminolysis, and transesterification; oxidation reactions of alkenes in unsaturated fatty acids and sterols, including autoxidation and oxidation by singlet oxygen; reactivity of headgroups, particularly with reactive carbonyl species; and E/Z isomerization of alkenes. The consequences of reactivity for biological activity and biophysical properties are also discussed.
Asunto(s)
Membrana Dobles de Lípidos , Lípidos de la Membrana , Lípidos de la Membrana/química , Membrana Dobles de Lípidos/química , Membrana Celular/metabolismo , Membranas/metabolismo , Fosfolípidos/metabolismo , Alquenos/metabolismoRESUMEN
In the field of nanomedicine, the development of targeted drug delivery aims to design more effective delivery systems that directly target cancer cells and tumours. The development of transdermal delivery mechanisms is promising. At the same time, these areas of research raise profound social and ethical questions and are tied to significant transformations in the nature of contemporary healthcare and personal subjectivity. Socio- political consideration of these issues is shaped by a wider set of debates concerning the societal dimensions of nanotechnology. In this paper we report findings from an interdisciplinary research project uilising semi-structured interviews with key-informants engaged in cancer research and health-care. We identified narrative constracts that shaped participants' responses to and understandings of novel nanomedicines. This analysis contributes to a growing body of literature on the social and ethical aspects of nanotechnology and nanomedicine, providing evidence for the engagement of publics in the early stage of technological developments.