|| Checking for direct PDF access through Ovid
Microspheres for the controlled release of an antisense oligonucleotide against the Transforming growth factor β1 were designed. Free oligonucleotide or its solid complexes with polyethylenimine (PEI) at different nitrogen/phosphate (N/P) ratios, were encapsulated within poly(lactide-co-glycolide) (PLGA) microspheres prepared by the multiple emulsion–solvent evaporation technique. The encapsulation of the oligonucleotide in form of solid complexes, the N/P ratio, as well as the PLGA type affected microspheres characteristics in term of loading, morphology, oligonucleotide distribution inside matrix and in vitro release profile. The designed microspheres allow the encapsulation and slow release of oligonucleotide/PEI solid complexes that should be effectively internalized inside cells.