Spinal cord injury is extremely debilitating, both at physiological and psychological levels, changing completely the patient's lifestyle. The introduction of biomaterials has opened a new window to develop a therapeutic approach to induce regeneration after injury due to similarities with extracellular matrix. Particularly, hydrogels have the ability to support axonal growth and endogenous regeneration. Moreover, they can also act as potential matrixes in which to load and deliver therapeutic agents at injury site. In this review, we highlight some important characteristics to be considered when designing hydrogels as delivery systems (DS), such as rheology, mesh size, swelling, degradation, gelation temperature and surface charge. Additionally, affinity-based release systems, incorporation of nanoparticles, or ion-mediated interactions are also pondered. Overall, hydrogel DS aim to promote a sustained, controlled and prolonged release at injury site, allowing a targeted oriented action of the therapeutic agent that will be used.

脊髓损伤在生理和心理层面都使人极度虚弱，彻底改变了患者的生活方式。由于生物材料与细胞外基质的相似性，生物材料的引入为开发诱导损伤后再生的治疗方法打开了新的窗口。特别是，水凝胶具有支持轴突生长和内源性再生的能力。此外，它们还可以充当潜在的基质，在损伤部位装载和递送治疗剂。在这篇综述中，我们强调了设计水凝胶作为递送系统（DS）时需要考虑的一些重要特征，例如流变学、网格尺寸、膨胀、降解、凝胶化温度和表面电荷。此外，还考虑了基于亲和力的释放系统、纳米颗粒的掺入或离子介导的相互作用。总体而言，水凝胶 DS 旨在促进损伤部位的持续、受控和延长释放，从而使所使用的治疗剂发挥有针对性的作用。