Embolisation devices from biomedical polymers for intra-arterial occlusion and drug delivery in the treatment of cancer

Therapeutic embolisation of blood vessels is a procedure commonly performed to treat a variety of conditions including bleeding problems, arterio-venous malformations (AVM), and benign and malignant hypervascular tumours. A range of degradable and permanent embolisation devices composed of natural and synthetic polymers may be used for such applications. Beads composed of a sulfonate-modified poly(vinyl alcohol) (PVA) hydrogel (DC Bead®) are finding wide-spread use for the occlusion and subsequent local, controlled and sustained delivery of chemotherapeutic agents directly within the vasculature of liver tumours. These so-called drug-eluting beads (DEB) are available in a series of calibrated size ranges for matching vessel size; have appropriate physico-mechanical properties to enable them to be delivered with ease through narrow gauge microcatheters; and have the ability to actively sequester and release positively charged anticancer drugs by an ion-exchange mechanism. This product has become one of the standards of care in the Western World for the treatment of intermediate primary liver cancer.