Poly (lactic/glycolic acid) microspheres containing antigen as a novel and potential agent of immunotherapy for allergic disorders.
In order to establish a safer and simpler antigen administration method in immunotherapy, we prepared biodegradable microspheres containing antigen and evaluated its safety and efficacy using guinea pigs. Poly (lactic/glycolic acid); (LGA) microspheres containing ovalbumin (OA) were fabricated by solvent evaporation. Over 70% of the OA was released from the microspheres within 3 days, and release was completed within 14 days in vivo. The local tissue reactions to the OA-LGA microspheres were apparently weaker than those to OA-alum. Repeated injections of high dose OA-LGA microspheres to OA-sensitized guinea pigs (high-LGA group) for 8 weeks at intervals of 2 weeks elicited an excellent therapeutic effect, i.e. a significant increase in the threshold value of antigen inhalation test, with a significant increase in IgG2 blocking antibody. The therapeutic efficacy of the high-LGA group was comparable to the conventional immunotherapy model (conventional group) and was superior to the antigen-alum model (alum group). We concluded that administration of antigen-LGA microspheres could become a new immunotherapeutic method for allergic disorders, being safer and requiring a lower frequency of antigen injections than the conventional method.
Takagi
I
I
Department of Otorhinolaryngology Nagoya City University Medical School.
Nishimura
J
J
Itoh
H
H
Baba
S
S
Kunimatsu
M
M
Sasaki
M
M
D000818:Animals; D000941:Antigens / Q000008:administration & dosage*; D016503:Drug Delivery Systems; D006168:Guinea Pigs; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007074:Immunoglobulin G / Q000032:analysis; D007167:Immunotherapy; D007267:Injections; D007773:Lactates / Q000008:administration & dosage*; D019344:Lactic Acid; D008863:Microspheres; D010047:Ovalbumin / Q000276:immunology; D011091:Polyesters; D011100:Polyglycolic Acid / Q000008:administration & dosage*; D011108:Polymers / Q000008:administration & dosage*
D000941:Antigens; D007074:Immunoglobulin G; D007773:Lactates; D011091:Polyesters; D011108:Polymers; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide); D010047:Ovalbumin