Fibrous PU scaffolds

For fibrous PU scaffolds, the mechanical environment is much more complex than 2D polyacrylamide since the scaffolds are porous, fibers are distributed within the constructs, and cells are attached to single fibers. As a result, the stiffness characteristics for both single fibers and scaffolds may have an impact on stan cell differentiation. We recently studied the effects of PU scaffold stiffness at small and large strains (before and after aUgmnent of fibers, respectively) and single fiber stiffness on cardiac differentiation of cardiosphere-derived cells (CDCs). The single fiber stiffness was... 

For tissue engineering applications, the fibrous PU scaffolds can also serve as a delivery vehicle of various biomolecules and drugs. The biomolecules and drugs can be incorporated into the scaffold during the electrospinning process. This method... 

The surface of the microporous PU scaffolds can be modified to control cell fate. Similar approaches as those used for fibrous PU scaffolds can be employed." " For example, to induce endothelial cell migration into scaffolds for accelerated vascularization, heparin was bound to the scaffold surface. An aminolysis step was first used to introduce amine groups on the surface, and then the cross-finking of heparin... 

Figure 21.13 PUCL-ra -PEG nerve scaffolds prior to and after the implantation (a) the sciatic nerve was transected and bridged by a PU nerve-guided scaffold (b) PUCL-ran-PEG implanted in rat after 9 weeks was surrounded with abundant capillaries (c) PUCL-ran-PEG degraded almost completely at 20 weeks implantation (d) autologous nerve-guided defected nerve in rat after 9 weeks (e) PCL implant in rat after 9 weeks was surrounded by a layer of fibrous connective tissue (f) sibcone tube implant in rat after 9 weeks.

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