title: Preparation and in vitro characterisation of Ehrlichia ruminantium plasmid DNA and proteins encapsulated into and DNA adsorbed onto biodegradable microparticles.
abstract: Four E. ruminantium 1H12 open reading frames and their proteins known to protect sheep against heartwater needle challenge were encapsulated into, or adsorbed onto poly(d,l-lactide-co-glycolide) microparticles. Microspheres with smooth surface and smaller than 5 μm diameters were produced, with high adsorption and encapsulation efficiencies. Gel electrophoresis showed that neither encapsulation nor adsorption affected the stability of the DNA or proteins. Cationic microparticles released ∼40% of plasmid DNA on day 1 while PLGA 50:50-COOH microparticles co-encapsulating plasmid DNA and polyvinyl alcohol only started to release from days 12-28. Recombinant proteins were released from PLGA 85:15 and homopolymer R 203 S microparticles in a biphasic manner with a high initial burst release (∼45-80%). In contrast, PLGA 50:50 microparticles had low (15-65%) initial burst release followed by (25-80%) release by days (days 28-42). A cocktail of these microparticles could therefore be used as single-dose auto-booster vaccine.
authors.affiliation: ARC-Onderstepoort Veterinary Institute, Onderstepoort, Pretoria, South Africa. tshikhudon@arc.agric.za
authors.forename: Ndavheleseni
authors.initials: N
authors.lastname: Tshikhudo
authors.forename: Alri
authors.initials: A
authors.lastname: Pretorius
authors.forename: John
authors.initials: J
authors.lastname: Putterill
authors.forename: Mirinda
authors.initials: M
authors.lastname: van Kleef
mesh_terms: D000327:Adsorption; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry; D004339:Drug Compounding; D016995:Ehrlichia ruminantium / Q000235:genetics*; D006357:Heartwater Disease / Q000276:immunology / Q000517:prevention & control*; D007700:Kinetics; D019344:Lactic Acid / Q000737:chemistry; D016366:Open Reading Frames; D010957:Plasmids / Q000302:isolation & purification; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012756:Sheep / Q000276:immunology; D019444:Vaccines, DNA / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D019444:Vaccines, DNA; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid