title: Endothelial targeting of semi-permeable polymer nanocarriers for enzyme therapies.
abstract: The medical utility of proteins, e.g. therapeutic enzymes, is greatly restricted by their labile nature and inadequate delivery. Most therapeutic enzymes do not accumulate in their targets and are inactivated by proteases. Targeting of enzymes encapsulated into substrate-permeable polymer nano-carriers (PNC) impermeable for proteases might overcome these limitations. To test this hypothesis, we designed endothelial targeted PNC loaded with catalase, an H(2)O(2)-detoxifying enzyme, and tested if this approach protects against vascular oxidative stress, a pathological process implicated in ischemia-reperfusion and other disease conditions. Encapsulation of catalase (MW 247 kD), peroxidase (MW 42 kD) and xanthine oxidase (XO, MW 300 kD) into approximately 300 nm diameter PNC composed of co-polymers of polyethylene glycol and poly-lactic/poly-glycolic acid (PEG-PLGA) was in the range approximately 10% for all enzymes. PNC/catalase and PNC/peroxidase were protected from external proteolysis and exerted enzymatic activity on their PNC diffusible substrates, H(2)O(2) and ortho-phenylendiamine, whereas activity of encapsulated XO was negligible due to polymer impermeability to the substrate. PNC targeted to platelet-endothelial cell (EC) adhesion molecule-1 delivered active encapsulated catalase to ECs and protected the endothelium against oxidative stress in cell culture and animal studies. Vascular targeting of PNC-loaded detoxifying enzymes may find wide medical applications including management of oxidative stress and other toxicities.
authors.affiliation: Institute for Environmental Medicine, University of Pennsylvania Medical Center, 1 John Morgan Building, 36th Street and Hamilton Walk, Philadelphia, PA 19104-6068, USA. dziubla@engr.uky.edu
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Dziubla
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Shuvaev
authors.forename: Nan Kang
authors.initials: NK
authors.lastname: Hong
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Hawkins
authors.forename: Muniswamy
authors.initials: M
authors.lastname: Madesh
authors.forename: Hajime
authors.initials: H
authors.lastname: Takano
authors.forename: Eric
authors.initials: E
authors.lastname: Simone
authors.forename: Marian T
authors.initials: MT
authors.lastname: Nakada
authors.forename: Aron
authors.initials: A
authors.lastname: Fisher
authors.forename: Steven M
authors.initials: SM
authors.lastname: Albelda
authors.forename: Vladimir R
authors.initials: VR
authors.lastname: Muzykantov
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002374:Catalase / Q000737:chemistry / Q000378:metabolism* / Q000627:therapeutic use; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D016503:Drug Delivery Systems; D042783:Endothelial Cells / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D049329:Nanostructures / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D015815:Cell Adhesion Molecules; D011108:Polymers; D002374:Catalase