Estudi sobre el recobriment de nanopartícules de plata amb biocorones com a teràpia alternativa als antibiòtics


Rivero Farré, Albert


In recent years, the number of infectious diseases that do not respond to antibiotic treatments has increased to become a major threat to public health systems worldwide. Several of these diseases are due to multi-resistant bacteria for which there is no effective treatment. As a result of this problem, silver nanoparticles have taken center stage due to their antibacterial properties, which are based on a combination of mechanisms of action other than the targets that antibiotics target. Knowing and controlling the physicochemical parameters of nanoparticles, as well as being able to modulate their surface is crucial to regulate their biological response, toxicity and stability.In this work, a state of the art will be carried out in order to identify which are the mechanisms of action of silver nanoparticles and what key parameters need to be controlled to maximize their bactericidal effect. Experimentally, starting from a formulation of silver nanoparticles based on the Tollens synthesis, it is intended to study by robust techniques whether the synthetic method allows the generation of reproducible silver nanoparticles with the appropriate properties to be able to carry out in vitro studies with bacteria. Finally, it is intended to coat the formulated nanoparticles with an albumin biocrown, which raises questions about how it will affect colloidal stability, what effect it will have on the observed toxicity and, ultimately, how the corona modulates the interaction between the nanoparticle and the bacteria.
After conducting a bibliographic study of the state of the art, it is clear that silver nanoparticles do not act by a single mechanism but that the antibacterial action is the result of a combination of several routes that, in some way that is not fully understood, act together. In addition, in order to optimize the antibacterial effect of silver nanoparticles, it is important to be able to control the physical-chemical parameters of the nanoparticles and their surface, since they play a relevant role in how the nanoparticle can attack the bacteria. Reproducible silver nanoparticles have been successfully synthesized experimentally and subsequently functionalized with a BSA protein crown. The formation of the crown, which has been observed in situ by confocal microscopy, has clearly improved the stability of the silver nanoparticles, which has made it possible to perform in vitro tests on Escherichia coli bacteria efficiently and even to obtain lyophilized samples. Finally, although the silver nanoparticles showed a similar bactericidal effect with or without coating, the stabilization by the albumin biocrown suggests that in real environments these nanoparticles would present a better behavior.



Texidó Bartés, Robert 


IQS SE - Undergraduate Program in Chemistry