title: Enhancement of immune response of HBsAg loaded poly (L-lactic acid) microspheres against hepatitis B through incorporation of alum and chitosan.
abstract: OBJECTIVE
  Poly (L-lactic acid) (PLA) microparticles encapsulating Hepatitis B surface antigen (HBsAg) with alum and chitosan were investigated for their potential as a vaccine delivery system.
  
  
  METHODS
  The microparticles, prepared using a water-in-oil-in-water (w/o/w) double emulsion solvent evaporation method with polyvinyl alcohol (PVA) or chitosan as the external phase stabilising agent showed a significant increase in the encapsulation efficiency of the antigen.
  
  
  RESULTS
  PLA-Alum and PLA-chitosan microparticles induced HBsAg serum specific IgG antibody responses significantly higher than PLA only microparticles and free antigen following subcutaneous administration. Chitosan not only imparted a positive charge to the surface of the microparticles but was also able to increase the serum specific IgG antibody responses significantly.
  
  
  CONCLUSIONS
  The cytokine assays showed that the serum IgG antibody response induced is different according to the formulation, indicated by the differential levels of interleukin 4 (IL-4), interleukin 6 (IL-6) and interferon gamma (IFN-gamma). The microparticles eliciting the highest IgG antibody response did not necessarily elicit the highest levels of the cytokines IL-4, IL-6 and IFN-gamma.
authors.affiliation: Centre for Drug Delivery Research, School of Pharmacy, University of London, London, UK.
authors.forename: Sreenivas
authors.initials: S
authors.lastname: Pandit
authors.forename: Erdal
authors.initials: E
authors.lastname: Cevher
authors.forename: Mohammed Gulrez
authors.initials: MG
authors.lastname: Zariwala
authors.forename: Satyanarayana
authors.initials: S
authors.lastname: Somavarapu
authors.forename: H Oya
authors.initials: HO
authors.lastname: Alpar
mesh_terms: D000536:Aluminum Hydroxide / Q000737:chemistry*; D000818:Animals; D002214:Capsules; D002478:Cells, Cultured; D048271:Chitosan / Q000737:chemistry*; D016207:Cytokines / Q000096:biosynthesis; D004337:Drug Carriers / Q000737:chemistry*; D006509:Hepatitis B / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D019344:Lactic Acid / Q000737:chemistry*; D008564:Membrane Potentials; D051379:Mice; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D012995:Solubility; D013154:Spleen / Q000276:immunology / Q000378:metabolism
chemical_list: D002214:Capsules; D016207:Cytokines; D004337:Drug Carriers; D006514:Hepatitis B Surface Antigens; D007074:Immunoglobulin G; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D000536:Aluminum Hydroxide; D048271:Chitosan