Until recently, self-assembling peptides showed unquestionable promising biomimetic properties and high biocompatibility. However, most of their potential applications in tissue engineering were precluded because of their poor biomechanics, intrinsically inherited from their self-assembling nature. Indeed, self-assembling usually involves weak transient non-covalent interactions that hardly allow for SAPs to feature stiffness and viscosity suited for cartilage/bone tissue engineering and electrospinning respectively. Gelain’s group successfully introduced branched molecules of SAPs and chemical cross-linkings as two possible new strategies to fill this gap. Branched SAPs were demonstrated to integrate within the self-assembled molecular structures when mixed with their linear counterparts, acting as “glues” for fragile SAP nanostructures. On the other hand, various cross-linkers (both synthetic and natural ones) work like molecular fasteners, increasing the packing order of pre-assembled SAPs, not to mention the chance of having SAPs subjected to different degrees of cross-linking so as to match the desired mechanics (topping increments of two orders of magnitude) and bioabsorption time. This opens up a plethora of new potential applications for SAPs, providing the missing point to fully exploit the self-assembling technology of peptides in tissue engineering, nanomedicine and likely other fields. One of these is electro-spinning, providing nano- and microfibrous scaffolds with the desired spatial orientation. By joining electro-spinning with cross-linked self-assembling technology it is now possible to produce biomimetic, flexible and 3D-defined scaffolds.