Polyurethane nanoparticles as drug delivery systems

CBO-Pll, a specific inhibitor of vascular endothelial growth factor and other angiogenic pathways, was efficiently incorporated in multifunctional anti-VC AM-1 and anti-ICAM-1 polyurethane-urea nanoparticles. These systems showed a significant and selective blockade of the proliferation only in inflamed endothelial cells and no cytotoxic effect was observed in healthy cells. Moreover, in vivo studies in CDl mice demonstrated that these nanoparticles reach the target site after intravenous administration. 

Nanotechnology-based therapeutics have exhibited clear benefits when compaied with unmodified drags, including improved half-lives, retention, targeting efficiency, and lower patient side effects. However, the problans to overcome are difficult This field has led to the identification of several important pitfalls in tirmor-targeted drag delivery  

Oveiestimation of the enhanced permeahUity and retention effect by which particles with a very small size (typically hposomes, nanoparticles, and macromolecular drags) should be accumulated into the tumor microenvironment due to the unique anatomy of tumor vessels. This postulate must be tested for every polymeric composition because it is dependent not only on size but also on chemical and surface properties. 

Misinterpretation of the potential usefulness of active drag targeting. 

Confusing formulation design, based on materials that are too complex and not broadly applicable in biomedicine. 

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