PEGylated adenoviruses for gene delivery to the intestinal epithelium by the oral route.
OBJECTIVE
Adenoviruses are being developed for diseases of the gastrointestinal tract. Several in vitro assays were used to predict stability of PEGylated adenovirus along the GI tract and determine in vivo gene transfer after oral administration.


METHODS
Recombinant adenovirus was modified with monomethoxypoly(ethylene) glycols activated by cyanuric chloride, succinimidyl succinate, and tresyl chloride. Transduction efficiency was assessed on Caco-2 cells. In vitro stability of viruses in simulated gastric fluid, pancreatic fluid, and bile was assessed by serial dilution on 293 cells. Transduction efficiency in vivo was determined by oral administration of 1 x 10(12) particles of unmodified or PEGylated virus to fasted Sprague-Dawley rats.


RESULTS
Titers of unmodified virus declined to undetectable levels after 40 min in simulated gastric fluid while the infectious titer of the modified vectors did not change for 3 h. Similar results were seen with simulated pancreatic fluid. PEGylation also enhanced adenoviral transduction efficiency in Caco-2 cells by a factor of 20. PEGylation enhanced adenovirus transduction efficiency 10- to 40-fold in vivo in intestinal segments that do not express significant amounts of adenovirus receptors (jejunum, colon) with transgene expression located in the crypt regions.


CONCLUSIONS
PEGylated adenoviruses are suitable gene delivery vehicles for oral administration.
Cheng
Xuan
X
College of Pharmacy, Division of Pharmaceutics, The University of Texas at Austin, Austin, Texas 78712, USA.
Ming
Xin
X
Croyle
Maria A
MA
D000256:Adenoviridae / Q000737:chemistry* / Q000235:genetics; D000284:Administration, Oral; D000818:Animals; D001646:Bile / Q000737:chemistry; D018938:Caco-2 Cells; D004355:Drug Stability; D005744:Gastric Acid / Q000737:chemistry; D015870:Gene Expression; D018014:Gene Transfer Techniques; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D010189:Pancreatic Juice / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D019076:Transgenes; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
D001616:beta-Galactosidase