Hydrogel-coils

Recently, new polymer-based bioactive coils have been investigated. Polymer coated platinum coils have been developed to swell on contact with blood. The hybrid-hydrogel coil can swell up to nine times its original volume, consequently maximizing coil volume while reducing the number of coils needed and surgical time [53]. Polyurethane coils have been shown to induce occlusion faster than metal coils in animal studies [54]. Furthermore, an SMP coil system has been developed from polyurethanes and tested in vitro [55]. 

Fig. 5.44a-d. A 39-year-old male, SAH 2 years previously, second recurrent aneurysm after embolization with bare coils (a) after hydrogel-coil-embolization (b), and 6 month FU with a stable result (c). d ToF-MRA after 2 years showed stable aneurysm occlusion... 

Hydrogels Based on a-Helical Coiled-Coil Structures... 

WangC, Stewart RJ, Kopecek J (1999) Hybrid hydrogels assembled from synthetic polymers and coiled-coil protein domains. Nature 397 417-420... 

Shen W (2005) Structure, dynamics, and properties of artificial protein hydrogels assembled through coiled-coil domains. California Institute of Technology, Pasadena... 

Liu B, Lewis AK, Shen W (2009) Physical hydrogels photo-cross-linked from self- assembled macromers for potential use in tissue engineering. Biomacromolecules 10 3182-3187 Vandermeulen GWM, Tziatzios C, Duncan R et al (2005) Peg-based hybrid block copolymers containing alpha-helical coiled coil peptide sequences control of self- assembly and preliminary biological evaluation. Macromolecules 38 761-769... 

Yang JY, Xu CY, Wang C et al (2006) Refolding hydrogels self-assembled from n- (2-hydroxypropyl)methacrylamide graft copolymers by antiparallel coiled- coil formation. Biomacromolecules 7 1187-1195... 

Hydrogels as Biomaterials Genetically Engineered Biomaterials Coiled Coils... 

Figure 3 Schematic illustration of a hybrid hydrogel system—genetically engineered coiled-coil protein domains used to crosslink synthetic water-soluble polymers. Divalent transition metal ions are shown to form complexes with nitrogen-oxygen-donor ligands on the synthetic polymer side chains and the terminal histidine residues in the coiled coils.

Figure 6 Swelling of hybrid hydrogels in response to temperature. The hydrogels were prepared from HPMA-DAMA copolymers, Ni(II), and KS590 coiled coil. The gels were equilibrated in PBS (pH 7.4) at 25°C prior to an increase in temperature. Rate of heating l°C/min plus 2 min equilibration time. Arrows indicate elevated temperatures of 25°C, 35°C, and 45°C, respectively. Modihed from Reference [35].

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