title: Formulation and characterization of poly (beta amino ester) microparticles for genetic vaccine delivery.
abstract: Microparticulate delivery systems are a promising and versatile enhancement to DNA vaccines because they can target large payloads of plasmid and immunomodulating materials to antigen presenting cells (APC). A pH sensitive poly-beta amino ester (PBAE) has been recently described which substantially increases adjuvancy and delivery efficiency of such microparticle formulations. This work describes the characterization and formulation considerations specific to these PBAE containing microparticles. PBAE increases the supercoiled content and overall effective loading of plasmid DNA. This polymer also significantly buffers the pH microenvironment created by ester bond degradation, rendering encapsulated plasmid more suitable for transfection. Release of plasmid from microparticles is controllable based on the amount of PBAE in the composition. Transfection is dependant upon phagocytosis, and is optimal for 15% and 25% PBAE microparticle formulations. However, larger quantities of PBAE may be toxic to cells indicating that the 15% PBAE formulation is a suitable candidate for delivery in future studies with disease specific, DNA vaccines.
authors.affiliation: Department of Chemical Engineering and Center for Cancer Research, Massachusetts Institute of Technology Cambridge, Massachusetts 02139, USA.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Little
authors.forename: David M
authors.initials: DM
authors.lastname: Lynn
authors.forename: Sidharth V
authors.initials: SV
authors.lastname: Puram
authors.forename: Robert
authors.initials: R
authors.lastname: Langer
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D055598:Chemical Phenomena; D002626:Chemistry, Pharmaceutical; D002627:Chemistry, Physical; D003713:Dendritic Cells / Q000187:drug effects; D004339:Drug Compounding; D016503:Drug Delivery Systems; D004952:Esters; D017930:Genes, Reporter / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D049329:Nanostructures; D009994:Osmolar Concentration; D010957:Plasmids / Q000008:administration & dosage; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry*; D012995:Solubility; D014162:Transfection; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000633:toxicity
chemical_list: D004952:Esters; D011108:Polymers; D019444:Vaccines, DNA; C507253:poly(beta-amino ester); D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid