The aim of this work is to safely transport bioadhesive microspheres loaded with DNA to intestine and to test their bioadhesive properties. Poly(vinyl alcohol) (PVA) microspheres were prepared by dispersion reticulation with glutaraldehyde and further aminated. These microspheres were firstly loaded with plasmid DNA by electrostatic interactions and then entrapped in cellulose acetate butyrate (CAB) microcapsules for gastric protection. The entrapped PVA microspheres do not have enough force by swelling to produce the rupture of CAB shell, therefore the resistance of microcapsules was weakened by incorporating different amount of the pH/thermosensitive polymer (SP) based on poly(N-isopropylacrylamide-co-methyl methacrylate-co-methacrylic acid) (NIPAAm-co-MM-co-MA). This polymer is insoluble in gastric juice at pH 1.2 and 37 °C, but quickly solubilized in intestinal fluids (pH 6.8 and pH 7.4). Therefore, DNA loaded PVA microspheres were not expelled in acidic media but were almost entir...
Cellulose acetate butyrate-pH/thermosensitive polymer microcapsules containing aminated poly(vinyl alcohol) microspheres for oral administration of DNA
BORTOLOTTI, Fabrizio;CORTESI, Rita;MENEGATTI, Enea
2007
Abstract
The aim of this work is to safely transport bioadhesive microspheres loaded with DNA to intestine and to test their bioadhesive properties. Poly(vinyl alcohol) (PVA) microspheres were prepared by dispersion reticulation with glutaraldehyde and further aminated. These microspheres were firstly loaded with plasmid DNA by electrostatic interactions and then entrapped in cellulose acetate butyrate (CAB) microcapsules for gastric protection. The entrapped PVA microspheres do not have enough force by swelling to produce the rupture of CAB shell, therefore the resistance of microcapsules was weakened by incorporating different amount of the pH/thermosensitive polymer (SP) based on poly(N-isopropylacrylamide-co-methyl methacrylate-co-methacrylic acid) (NIPAAm-co-MM-co-MA). This polymer is insoluble in gastric juice at pH 1.2 and 37 °C, but quickly solubilized in intestinal fluids (pH 6.8 and pH 7.4). Therefore, DNA loaded PVA microspheres were not expelled in acidic media but were almost entir...I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
