Polymer nanocarriers protecting active enzyme cargo against proteolysis

Polymer nanocarriers protecting active enzyme cargo against proteolysis
February 2005
Thomas D. Dziubla, a, Adnan Karim, a and Vladimir R. Muzykantova, b
a Institute for Environmental Medicine, University of Pennsylvania School of Medicine, 1 John Morgan/6068, 3620 Hamilton Walk, Philadelphia, PA 19104, United States
b Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, United States
Journal of Controlled Release Volume 102, Issue 2 , 2 February 2005, Pages 427-439
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Abstract
Polymeric nanocarriers (PNCs), proposed as an attractive vehicle for vascular drug delivery, remain an orphan technology for enzyme therapies due to poor loading and inactivation of protein cargoes. To unite enzyme delivery by PNC with a clinically relevant goal of containment of vascular oxidative stress, a novel freeze?thaw encapsulation strategy was designed and provides not, vert, similar20% efficiency loading of an active large antioxidant enzyme, catalase, into PNC (200?300 nm) composed of biodegradable block copolymers poly(ethylene glycol)-b-poly(lactic-glycolic acid). Catalase's substrate, H2O2, was freely diffusible in the PNC polymer. Furthermore, PNC-loaded catalase stably retained 25?30% of H2O2-degrading activity for at least 18 h in a proteolytic environment, while free catalase lost activity within 1 h. Delivery and protection of catalase from lysosomal degradation afforded by PNC nanotechnology may advance effectiveness and duration of treatment of diverse disease conditions associated with vascular oxidative stress.