title: Effect of cationic grafted copolymer structure on the encapsulation of bovine serum albumin.
abstract: The aim of the present study was to evaluate a library of poly-L-lysine (PLL)-graft (g)-polyethylene glycol (PEG) copolymers for the ability to encapsulate effectively a model protein, bovine serum albumin (BSA), and to characterize the stability and protein function of the resulting nanoparticle. A library of nine grafted copolymers was produced by varying PLL molecular weight and PEG grafting ratio. Electrostatic self-assembly of the protein and the grafted copolymer drove encapsulation. The formation of protein/polymer nanoparticles with a core/shell structure was confirmed using PAGE, dynamic light scattering, and electron microscopy. Encapsulation of the BSA into nanoparticles was strongly dependent on the copolymer-to-protein mass ratio, PEG grafting ratio, and PLL molecular weight. A copolymer-to-protein mass ratio of 7:1 and higher was generally required for high levels of encapsulation, and under these conditions, no loss of protein activity was observed. Copolymer characteristics also influenced nanoparticle resistance to polyanions and protease degradation. The results indicate that a copolymer of 15-30 kDa PLL, with a PEG grafting ratio of 10:1, is most promising for protein delivery.
authors.affiliation: School of Chemical Engineering, Oklahoma State University, Stillwater, OK 74078, United States.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Flynn
authors.affiliation: School of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078, United States.
authors.forename: Ç Özge
authors.initials: ÇÖ
authors.lastname: Topal
authors.affiliation: School of Chemical Engineering, Oklahoma State University, Stillwater, OK 74078, United States.
authors.forename: Rangika S
authors.initials: RS
authors.lastname: Hikkaduwa Koralege
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, United States.
authors.forename: Steve
authors.initials: S
authors.lastname: Hartson
authors.affiliation: Department of Physiological Sciences, Oklahoma State University, Stillwater, OK 74078, United States.
authors.forename: Ashish
authors.initials: A
authors.lastname: Ranjan
authors.affiliation: Department of Physiological Sciences, Oklahoma State University, Stillwater, OK 74078, United States.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Physiological Sciences, Oklahoma State University, Stillwater, OK 74078, United States.
authors.forename: Carey
authors.initials: C
authors.lastname: Pope
authors.affiliation: School of Chemical Engineering, Oklahoma State University, Stillwater, OK 74078, United States. Electronic address: josh.ramsey@okstate.edu.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Ramsey
mesh_terms: D000818:Animals; D002412:Cations / Q000737:chemistry; D002417:Cattle; D002626:Chemistry, Pharmaceutical; D000067493:Dynamic Light Scattering; D004591:Electrophoresis, Polyacrylamide Gel; D008854:Microscopy, Electron; D008970:Molecular Weight; D053758:Nanoparticles / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011107:Polylysine / Q000031:analogs & derivatives* / Q000737:chemistry; D059748:Proteolysis; D012710:Serum Albumin, Bovine / Q000737:chemistry*
chemical_list: D002412:Cations; C443714:polylysine-graft-(poly(ethylene glycol)); D011107:Polylysine; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols
keywords: Nanoparticle; Polyion Complex; Protein Delivery