title: Encapsulation of GFP in Complex Coacervate Core Micelles.
abstract: Protein encapsulation with polymers has a high potential for drug delivery, enzyme protection and stabilization. Formation of such structures can be achieved by the use of polyelectrolytes to generate so-called complex coacervate core micelles (C3Ms). Here, encapsulation of enhanced green fluorescent protein (EGFP) was investigated using a cationic-neutral diblock copolymer of two different sizes: poly(2-methyl-vinyl-pyridinium)41-b-poly(ethylene-oxide)205 and poly(2-methyl-vinyl-pyridinium)128-b-poly(ethylene-oxide)477. Dynamic light scattering and fluorescence correlation spectroscopy (FCS) revealed a preferred micellar composition (PMC) with a positive charge composition of 0.65 for both diblock copolymers and micellar hydrodynamic radii of approximately 34 nm. FCS data show that at the PMC, C3Ms are formed above 100 nM EGFP, independent of polymer length. Mixtures of EGFP and nonfluorescent GFP were used to quantify the amount of GFP molecules per C3M, resulting in approximately 450 GFPs encapsulated per micelle. This study shows that FCS can be successfully applied for the characterization of protein-containing C3Ms.
authors: †Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter, and §MicroSpectroscopy Centre Wageningen, Wageningen University, Wageningen, The Netherlands.
authors: Antsje
authors: A
authors: Nolles
authors: †Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter, and §MicroSpectroscopy Centre Wageningen, Wageningen University, Wageningen, The Netherlands.
authors: Adrie H
authors: AH
authors: Westphal
authors: †Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter, and §MicroSpectroscopy Centre Wageningen, Wageningen University, Wageningen, The Netherlands.
authors: Jacob A
authors: JA
authors: de Hoop
authors: †Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter, and §MicroSpectroscopy Centre Wageningen, Wageningen University, Wageningen, The Netherlands.
authors: Remco G
authors: RG
authors: Fokkink
authors: †Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter, and §MicroSpectroscopy Centre Wageningen, Wageningen University, Wageningen, The Netherlands.
authors: J Mieke
authors: JM
authors: Kleijn
authors: †Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter, and §MicroSpectroscopy Centre Wageningen, Wageningen University, Wageningen, The Netherlands.
authors: Willem J H
authors: WJ
authors: van Berkel
authors: †Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter, and §MicroSpectroscopy Centre Wageningen, Wageningen University, Wageningen, The Netherlands.
authors: Jan Willem
authors: JW
authors: Borst
mesh_terms: D016503:Drug Delivery Systems; D049452:Green Fluorescent Proteins / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*
chemical_list: D008823:Micelles; D011108:Polymers; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D011092:Polyethylene Glycols