Plasmídeos formulados com nanopartículas catiônicas: análise da estabilidade físico química e biológica

Abstract

The plasmids (pDNAs) have been standing out regarding to its application at biotechnology, mostly in DNA vaccination and genic therapy. pDNAs are DNA molecules with extra chromosomal double bands, presenting circular shape and have different isoforms. The Food and Drug Administration recommends that during pDNAs utilization on immunization protocols, they must be at least 80% on its super-curled isoform, once the studies assign that super-curled isoforms have a larger access to the interior of cells. Super curled isoform may be altered by chemical, physical and biological factors. Owing to its importance at pDNAs structure stability at biological function, this study aims to evaluate the pDNAs stability used at biotechnology, ands tests a nanoformulation with polyethyleneimine (PEI) associated to pDNAs, in order to promote a stability and bioavailability increasing of pDNAs. We evaluate the temperature effect at incubation, plasmid size and nucleases concentrations under super-curled isoform conservation. Also, it was evaluated pDNAs stability using functionalized nanoparticles with PEI through time variables, nucleases concentration and comparing to non functionalized nanoparticles formulated pDNAs. On 37°C and 42°C temperatures, there was higher degradation on plasmids, as well as higher serum concentration, presenting super-curly isoforms only at 1:64 dilution. The smaller sized plasmid presented lower degradation in all the tests. The preparation of functionalized nanoparticles with PEI associated to pDNA showed to be a promising alternative of protection against enzymatic degradation, with 100% efficiency of plasmid association. However, it requires more in vitro and in vivo studies to verify security factors and genic transference rate.