Biodegradable alginate microspheres as a delivery system for naked DNA

Sodium alginate is a naturally occurring polysaccharide that can easily be polymerized into a solid matrix to form microspheres, These biodegradable m icrospheres were used to encapsulate plasmid DNA containing the bacterial b eta-galactosidase (LacZ) gene under the control of: either the cytomegalovi rus (CMV) immediate-early promoter or the Rous sarcoma virus (RSV) early pr omoter. Mice inoculated orally with microspheres containing plasmid DNA exp ressed LacZ in the intestine, spleen and liver. Inoculation; of mice with m icrospheres containing both the plasmid DNA and bovine adenovirus type 3 (B Ad3) resulted in a significant increase in LacZ expression compared to thos e inoculated with microspheres containing only the plasmid DNA. Our results suggest that adenoviruses are capable of augumenting transgene expression by plasmid DNA both in vitro and in vivo.