title: Influence of surface charge of PLGA particles of recombinant hepatitis B surface antigen in enhancing systemic and mucosal immune responses.
abstract: This study investigates the efficacy of surface-modified microspheres of hepatitis B surface antigen (HBsAg) in eliciting systemic and mucosal immune responses. Positively charged poly(D,L-lactic-co-glycolic acid) microspheres were prepared by a double-emulsion solvent-evaporation method with cationic agents--stearylamine and polyethylenimine--in the external aqueous phase. Formulations were characterized for morphology, size, density, aerodynamic diameter, entrapment efficiency and in vitro drug-release profile. Immunization was performed after pulmonary administration of the formulations to female Sprague-Dawley rats and the immune response was monitored by measuring IgG levels in serum and secretory (sIgA) levels in salivary, vaginal and bronchoalveolar lavage fluids. The cell-mediated immune response was studied by measuring cytokine levels in spleen homogenates, and a cytotoxicity study was performed with Calu-3 cell line. The aerodynamic diameter of the particles was within the respirable range, with the exception of stearylamine-modified particles. Zeta potential values moved from negative (-6.76 mV) for unmodified formulations to positive (+0.515 mV) for polyethylenimine-modified particles. Compared to unmodified formulations, polyethylenimine-based formulations showed continuous release of antigen over a period of 28-42 days and increased levels of IgG in serum and sIgA in salivary, vaginal and bronchoalveolar lavage. Further, cytokine levels-interferon gamma and interleukin-2-were increased in spleen homogenates. The viability of Calu-3 cells was not adversely affected by the microparticles. In summation, this study establishes that positive surface charges on poly(D,L-lactic-co-glycolic acid) particles containing HBsAg enhances both the systemic and mucosal immune response upon immunization via the respiratory route.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, 1300 Coulter, Amarillo, TX 79106, United States.
authors.forename: Chandan
authors.initials: C
authors.lastname: Thomas
authors.forename: Vivek
authors.initials: V
authors.lastname: Gupta
authors.forename: Fakhrul
authors.initials: F
authors.lastname: Ahsan
mesh_terms: D000280:Administration, Inhalation; D000588:Amines / Q000737:chemistry; D000818:Animals; D001980:Bronchi / Q000166:cytology / Q000276:immunology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000378:metabolism; D003692:Delayed-Action Preparations; D004847:Epithelial Cells / Q000276:immunology; D005260:Female; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage* / Q000276:immunology; D018928:Immunity, Mucosal; D007071:Immunoglobulin A, Secretory / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D019344:Lactic Acid / Q000737:chemistry*; D008863:Microspheres; D010316:Particle Size; D011094:Polyethyleneimine / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000588:Amines; D016207:Cytokines; D003692:Delayed-Action Preparations; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011094:Polyethyleneimine; C009317:stearylamine