Lipid nanoparticles as vehicles for macromolecules: nucleic acids and peptides

Traditional drug delivery systems are not efficient for peptide, protein and nucleic acid (plasmid DNA, oligonucleotides or short interfering RNA) delivery, thereby LNP have been exploited as potential delivery and targeting systems of these molecules. Since their discovery in the early 90's several research groups have focused their efforts on the improvement of this kind of nanocarriers in terms of effectiveness and safety. This review features the recent and most relevant patents related to these topics, with particular attention to targeting and protection from environmental agents. Moreover, in the case of nucleic acids strategies to improve transfection mediated by lipid nanoparticles (entrance to the cells, intracellular distribution or going through nuclear envelope) will be assessed. Regarding peptides and proteins, enhancement of encapsulation efficiency and absorption through mucoses are the main studied drawbacks. Finally, this work also includes a summary of the existing patents about the use of LNP as immune response adjuvants by using either plasmid DNA or proteins.