1. Int J Pharm. 2010 Oct 15;398(1-2):210-8. Epub 2010 Jul 30.

Bioadhesive nanoparticles of fungal chitosan for oral DNA delivery.

Plapied L, Vandermeulen G, Vroman B, Préat V, des Rieux A.

Université catholique de Louvain, Louvain Drug Research Institute, Unité de
Pharmacie Galénique, 1200 Brussels, Belgium.

Chitosan is an ideal candidate for oral DNA delivery due to its mucoadhesive
properties. Chitosan (CS) produced under GMP conditions from fungal source was
used to encapsulate a plasmid DNA coding for a reporter gene. Nanoparticles made 
by complex coacervation of CS and DNA had a size around 200 nm, a positive zeta
potential, a high association of DNA and protected the plasmid against nuclease
degradation. Their transfection ability was assessed in differentiated intestinal
Caco-2 cells. An N/P ratio of 4 and a DNA concentration of 8 microg/ml were the
optimal conditions leading to a transfection efficiency similar to the one
reached with polyethyleneimine (PEI)-DNA complexes without cytotoxicity. M cells 
in monolayers influenced DNA uptake up to 8 microg of DNA/ml when complexed with 
CS. Fungal trimethylchitosan was also tested but the complexes interactions were 
too strong to induce transfection in vitro. Confocal microscopy studies showed
that CS/DNA and PEI/DNA nanoparticles were found at the apical surface of cell
monolayers and DNA was co-localized within the nucleus. Quantification seemed to 
show that more DNA was associated with the cells when incubated with CS
nanoparticles and that the presence of M cells slightly influenced DNA uptake
when complexed with CS. In conclusion, we developed a new nanocarrier made of
fungal CS promising for oral gene delivery and oral DNA vaccination.


PMID: 20674728 [PubMed - in process]