title: Thermodynamic and kinetic stability of DSPE-PEG(2000) micelles in the presence of bovine serum albumin.
abstract: This work investigated the stability of DSPE-PEG(2000) micelles in the presence of bovine serum albumin (BSA). DSPE-PEG(2000) was found to exist in equilibrium among monomeric, micellar, and BSA-bound states, and this equilibrium shifted toward the BSA-bound state when the temperature increased from 20 to 37 °C. The micellar state is thermodynamically unstable at both temperatures when the concentration of BSA approaches that of DSPE-PEG(2000), and micelle breakup occurs with a first-order time constant of 130 ± 9 min at 20 °C and 7.8 ± 1.6 min at 37 °C. Thus, previous targeting experiments that demonstrate synergistic effects in multiply functionalized DSPE-PEG(2000) micelles are likely due to targeting that occurs on a timescale faster than that of micelle breakup. Micelle breakup was limited by diffusion at 20 °C whereas at 37 °C monomer desorption from the micelle was the rate-limiting step. These findings give clear guidance concerning the lifetimes of micelles that may be used as diagnostic and therapeutic nanoparticles.
authors.affiliation: Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Kastantin
authors.forename: Dimitris
authors.initials: D
authors.lastname: Missirlis
authors.forename: Matthew
authors.initials: M
authors.lastname: Black
authors.forename: Badriprasad
authors.initials: B
authors.lastname: Ananthanarayanan
authors.forename: David
authors.initials: D
authors.lastname: Peters
authors.forename: Matthew
authors.initials: M
authors.lastname: Tirrell
mesh_terms: D000818:Animals; D002417:Cattle; D007700:Kinetics; D008823:Micelles; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D008823:Micelles; D010714:Phosphatidylethanolamines; C038089:1,2-distearoylphosphatidylethanolamine; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols