Effect of Polymer Coated Needles on Infusate Backflow During Convection-Enhanced Delivery

Abstract

Currently, many central nervous system disorders cannot be treated effectively using conventional drug delivery methods such as oral and intravenous drug administration. Therapeutic agents for such disorders often contain polar proteins with high molecular weight compounds (i.e. enzymes, antibodies and gene vectors) that are too large to diffuse through the tight junctions of the blood brain barrier (BBB) [1]. Moreover, it has been shown that low molecular weight compounds, though highly diffusive within brain tissue and tumors, have a limited distribution of just a few millimeters from the site of delivery due to loss via capillaries [1]. Direct infusion into the brain using convection-enhanced delivery (CED) as a supplement to diffusion is a technique that can circumvent these limitations by allowing one to utilize bulk flow to achieve much greater drug concentrations throughout the targeted area [1].