Stimuli-Responsive Nanocomposite: Potential Injectable Embolization Agent

Hepatocellular carcinoma (HCC) is the sixth most common form of cancer. [ 1 ] Transcatheter arterial embolization (TAE) is a treatment referring to “starving” the cells in liver tumors through arterial occlusion. [ 2 ] In TAE, the embolic materials must display properties of both low viscosity in the delivery process and high strength in the embolic process. [ 3 ] Lipiodol can reach the peripheral arteries rapidly, but it is easily eliminated by blood scouring. On the other hand, many synthetic materials [e.g., Gelfoam, Ivalon, poly(vinyl alcohol) (PVA) microparticles] and natural materials (blood clots) have been used for occlusion, but there are also some disadvantages in their clinical application. [ 3–5 ] Some polymer microspheres like PVA particles have a good permanent embolic effect in TAE therapy, but they have diffi culty moving into the peripheral arteries because of their relatively large size. [ 6 ] Nanostructured materials, having a low viscosity in the delivery process, a high occlusion strength, and excellent biocompatibility are effective for this purpose. Zhao et al. reported that a temperature-sensitive poly( N -isopropylacrylamideco -butyl methacrylate) nanosized gel could be used as embolic material. However, the strength and the biocompatibility of these materials still need improvement to be used as embolic agents. [ 3 ] Previously, our group reported on thermoresponsive BC whisker/poly(NIPAMco -BMA) nanogel complexes as novel blood vessel embolic materials in the interventional therapy of liver tumors. [ 7 ]