title: A theoretical formalism for aggregation of peroxidized lipids and plasma membrane stability during photolysis.
abstract: The objective of this investigation was to examine, from a theoretical perspective, the mechanism underlying the lysis of plasma membranes by photoinduced, chemically mediated damage such as is found in photolysis. Toward this end, a model is presented which relates the membrane lifetime to the thermodynamic parameters of the membrane components based upon the kinetic theory of aggregate formation. The formalism includes a standard birth/death process for the formation of damaged membrane components (i.e., peroxidized lipids) as well as a terminating condensation process for the formation of aggregates of peroxidized plasma membrane lipids. Our theory predicts that 1) the membrane lifetime is inversely correlated with predicted rate of membrane damage; 2) an upper limit on the duration of membrane damage exists, above which the mean and variance of the membrane lifetime is independent of further membrane damage; and 3) both the mean and variance of the time of membrane lifetime distribution are correlated with the number of sites that may be damaged to form a single membrane defect. The model provides a framework to optimize the lysis of cell membranes by photodynamic therapy.
authors.affiliation: Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital, Harvard Medical School, and Shriners Burns Hospital, Boston, Massachusetts 02139 USA.
authors.forename: N A
authors.initials: NA
authors.lastname: Busch
authors.forename: M L
authors.initials: ML
authors.lastname: Yarmush
authors.forename: M
authors.initials: M
authors.lastname: Toner
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects*; D006801:Humans; D066298:In Vitro Techniques; D008054:Lipid Peroxides / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects*; D046911:Macromolecular Substances; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism; D010782:Photolysis; D026082:Singlet Oxygen
chemical_list: D008054:Lipid Peroxides; D046911:Macromolecular Substances; D008563:Membrane Lipids; D026082:Singlet Oxygen; D010100:Oxygen