Usefulness of the Behavior of Fibroblast Attachment to Coils in Thermoreversible Gelation Polymer for Aneurysmal Coil Treatment

Background: Post embolization aneurysm reccurence is still a drawback in endovascular coiling for cerebral aneuryms. That stimulated reaearch into new promising embolic materials, as the Thermoreversible Gelation Polymer (TGP) when used as cell culture medium with its temperature related properties. We evaluated proliferative properties of fibroblast cell cultures in association with metalic coils.Methods: Intial assessment of cell viability was done for 3T3 (mouse fibroblast) and A172 (glioma cell) lines for 6 and 16 days in TGP solid phase and media. After that TGP was liquified and cell attachment confirmed. Next, fibroblasts were cultivated under the same conditions adding Guglielmi detachable coils for 24 h and 3 days with TGP, evaluating cell attachment and proliferation on coils. Last, the time course of cell proliferation was evaluated, comparing cell numbers on equal coil surface areas for 1,3,5,7,10,14 and 21 days in TGP. Electron microscopy was used for cell assessment on the coils.Results: Fibroblasts survive and show satisfactory viability in TGP. In liquefied TGP after 6 days and 16days, both cell types temporally extended processes and attached on flask`s bottom. Next after 24 h and 3 days fibroblast cultivation with coils in TGP, cells extended processes and attached to coils, indicating some proliferation and clustering. Last, the day 1 attached cell numbers on coils cultivated in TGP gradually decreased until day 10 and later increased again to just below day 1 level. However, both fibroblast and glioma cells in TGP did not extend processes, move or proliferate, and had spherical shape while in solid TGP.Conclusion: Fibroblasts attachment and long survival on coils in TGP may facilitate aneurysm treatment to achieve better volume embolization rate and improve intra-aneurysmal thrombus organization.