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Endothelial targeting of semi-permeable polymer nanocarriers for enzyme therapies

Paper ID Volume ID Publish Year Pages File Format Full-Text
11350 734 2008 13 PDF Available
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 H2O2-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 ∼300 nm diameter PNC composed of co-polymers of polyethylene glycol and poly-lactic/poly-glycolic acid (PEG–PLGA) was in the range ∼10% for all enzymes. PNC/catalase and PNC/peroxidase were protected from external proteolysis and exerted enzymatic activity on their PNC diffusible substrates, H2O2 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.

Keywords
ALI, acute lung injury; BSA, bovine serum albumin; CAM, cell adhesion molecule; DCC, 2, 2-dicyclocarbodiimide; DCF, 5-(and-6)-chloromethyl-2′, 7′-dichlorodihydrofluorescein diacetate; DCM, dichloromethane; DLS, dynamic light scattering; EC, endothelial ce
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Endothelial targeting of semi-permeable polymer nanocarriers for enzyme therapies
Publisher
Database: Elsevier - ScienceDirect
Journal: Biomaterials - Volume 29, Issue 2, January 2008, Pages 215–227
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering