1	A New Thermo-reversible liquid embolic agent 1.Department of Neurosurgery, The Jikei University School of Medicine, Tokyo Japan 2.Advanced Research Center for Science and Engineering, Waseda University , Tokyo Japan 3.Division of interventional Neuroradiology, University of California, Los Angeles, CA
2	OBJECTIVE We developed a new embolic agent, Thermo-reversible Gelation Polymer (TGP). This polymer own unique characteristics that can be solidified by body temperature. This polymer can be used as tissue engineering scaffold and drug delivery vehicle. We evaluated angiographic and histopathological findings of this new liquid embolic agent.
3	MATERIALS TGP has a sol-gel transition temperature (TT). It becomes a liquid state at a temperature lower than the sol-gel transition temperature and becomes gel state above TT. It can also slowly deliver biologically active substance such as growth factor or engineered cells. The polymer was mixed with radiopaque material without solvent.
4	Example of cell growth in TGP
5	Embolization like coils TGP delivery in the kidney
6	Thermo-reversible
7	Thermo-reversible
8	METHODS
9	aneurysm
10	Experiment A TGP was used in combination with balloon protection across the neck of aneurysms.
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13	TGP injection with Balloon Protection
14	TGP injection with Balloon Protection Follow up Angiography
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16	Experiment B Prior to TGP injection, the microstent was placed at the neck of the aneurysm.
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18	STENT
19	TGP embplization
20	Post embolization
21	After day 14 Follow up Angiography
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23	Macroscopic View
24	Pathology
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26	Table
27	Microscopic View
28	Discussion Non toxic, no solvent Thermo-reversible　polymer Solidify without polymerzation and precipitation Design for tissue engineering Drug delivery
29	Embolic material
30	Discussion We design to develop a new cooling microcatheter. We try to mix TGP and drug. (include FGF). We will use embolization without protection devices. (STENT or GDC etc…)
31	TGP increasing adhesiveness Adhesiveness We can use embolization without protection device
32	CONCLUSIONS We developed a new embolic agent thermo-reversible gelation polymer. (TGP) This new thermo-reversible liquid embolic agent can be used effectively for embolization of aneurysms in swine. Optimal drug delivery system and microcatheter design are currently under development. Further modifications such as mechanical stability would be mandatory prior to clinical application.
33	Thermo-reversible gelation polymer (TGP) This TGP can be safely embolized experimental aneurysm with protection devices. Further modifications such as mechanical stability or drug delivery system will be necessary prior to clinical application.