title: Immune responses to orally administered PLGA microparticles: influence of oil vehicles and surfactive agents.
abstract: Lipid vehicles and surfactive agents have been successfully used to increase oral absorption and availability of free and encapsulated proteins. In order to investigate if these vehicles could also enhance the serum IgG responses elicited after the oral administration of protein antigens, free bovine serum albumin (BSA) was orally administered to Balb/c mice in different vehicles: a 0.3% sodium bicarbonate aqueous solution, and ethyl oleate/0.3% sodium bicarbonate o/w emulsion (1:9 v/v containing 0.01 microM sodium deoxycholate and 1% poloxamer 188) or ethyl oleate containing the previously described surfactive agents. The immune response elicited by the free antigen was enhanced by the use of these substances, especially when the free protein was administered as an oil suspension containing the surfactive agents. However, when protein loaded 1 microm PLGA particles were orally administered, the use of these enhancers did not result in an improvement of the serum IgG responses, and only the suspension of the spheres in ethyl oleate containing the poloxamer and the bile salt elicited a similar immune response to that achieved with their suspension into an aqueous solution without any enhancer, which suggests that these enhancers are not capable of increasing the absorption of particulated antigens.
authors.affiliation: Laboratory of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of the Basque Country (UPV-EHU), Paseo de la Universidad no 7, 001006 Vitoria-Gasteiz, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Gutierro
authors.forename: R M
authors.initials: RM
authors.lastname: Hernández
authors.forename: M
authors.initials: M
authors.lastname: Igartua
authors.forename: A R
authors.initials: AR
authors.lastname: Gascón
authors.forename: J L
authors.initials: JL
authors.lastname: Pedraz
mesh_terms: D000284:Administration, Oral; D000818:Animals; D003840:Deoxycholic Acid / Q000276:immunology; D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems; D005079:Excipients / Q000494:pharmacology; D005260:Female; D007074:Immunoglobulin G / Q000096:biosynthesis; D019344:Lactic Acid / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008863:Microspheres; D009829:Oleic Acids / Q000276:immunology; D020442:Poloxamer / Q000494:pharmacology; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D012710:Serum Albumin, Bovine / Q000276:immunology; D013501:Surface-Active Agents / Q000494:pharmacology
chemical_list: D004337:Drug Carriers; D005079:Excipients; D007074:Immunoglobulin G; D009829:Oleic Acids; D011108:Polymers; D013501:Surface-Active Agents; D003840:Deoxycholic Acid; D020442:Poloxamer; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D012710:Serum Albumin, Bovine; D019344:Lactic Acid; C033180:ethyl oleate