Multi-faced study for the development of enhanced transfection systems


Balcells García, Laura 


The current transfer of knowledge from a research laboratory scale to pharmaceutical products and human therapies is limited, among other reasons, due to the perception of cells as black boxes, where there are inputs and outputs but little attention is devoted to the inner cell processes governing the overall results. This doctoral thesis proposes a method to study the cellular mechanisms involved in cell uptake and transfection that often remain unnoticed. That is, through the development of a new class of multicomponent nanoparticles derived from a well-performing polymeric type gene delivery system, it is here projected an inspection from inside the cells that will allow not only a better understanding of cell experiment results, but also setting the basis for an innovative and improved cell therapy platform. First, the intracellular mechanisms of autophagy and exosomes production will be studied using OM-pBAE polyplexes in combination with metallic nanoparticles. The role of both the polymeric and the metallic component of the system will be investigated in these two cell mechanisms that are induced upon cell transfection. Also, the intracellular location assessment of the complexes will be monitored. Then, the interactions of these gene delivery systems with the proteins present in any given biological medium will be analyzed, since they have a great impact in cellular internalization. And finally, with the knowledge on both the cellular mechanisms behind cell transfection and the effect of protein corona on the cell uptake profiles of different nanoparticles, it will be proposed the application of our gene delivery systems to a more challenging purpose: the modification of mesenchymal stem cells for further use as cell therapy strategies. In conclusion, in this thesis, multicomponent nanoparticles have been employed to perform a thorough study of the cellular mechanisms induced upon cell transfection. Gene delivery systems composed of polyplexes made of OM-pBAEs and pDNA and a metallic component being either gold nanoparticles or SPIONs have been used to unbox cells and analyze the intra and intercellular processes that dictate the fate of internalized vectors – namely autophagy and exosomes production –, study their interaction with proteins and demonstrate that this phenomenon is key for their cellular uptake, and finally apply the knowledge of their properties and abilities to genetically modify reluctant to transfection cells that are used for cell therapy strategies.




Borrós Gómez, Salvador 
Cascante Cirera, Anna  


IQS SE - Bioenginyeria

Date of defense