Los liposomas como modelo de nanopartículas en aplicaciones biomédicas

Abstract

Nanotechnology is an emerging scientific field, gaining more and more relevance each year and its interaction with other fields is leading to the formation and development of new disciplines, such as nanomedicine and nanobiotechnology, which involve the use of nanoparticles. There are many different types of nanoparticles of notable significance, currently in use, in both medicine and nanotechnology but also in the fields of electronics, construction, and environmental sciences, to name but a few. Some of the most important nanoparticles are quantum dots, magnetic nanoparticles, gold nanoparticles, dendrimers, carbon nanotubes and liposomes. Due to their biomedical applications, liposomes have a key role to play and will therefore be discussed in more detail. Various techniques can be used in the production of liposomes, which will determine the final properties of the nanoparticle, and whether it is best suited for one purpose or another. In addition, many different techniques are used in the characterization of liposomes, including the study of the size, lamerallity or electric potential of each. The emphasis of this work regarding the medical applications of liposomes will focus on their role as nanocarriers for drugs, genes, and contrast agents, in both therapy and diagnosis. Liposomes will help to increase the bioavailability of their cargo and pinpoint it to a certain location in the body, through passive or active targeting. Liposomes can also be modified to enable a selective release of their cargo, in response to certain external or internal stimuli. It should be noted that nanoparticles have certain limitations regarding the possible toxic effect they may have on the body, especially through the formation of reactive oxygen species. One particular application of liposomes, explored experimentally, is their functionalization with mannose to allow its intake by brain macrophages while they encapsulate a siRNA, which will regulate the expression of a certain enzyme, related with inflammation.