Soft, precision engineered porous, hydrogel scaffolds mechanically tailored toward applications in the central nervous system

Diseases and traumatic injuries to the central nervous system (CNS) demand the development of new biomaterials to improve healing and treatment options. Matching material mechanical properties to specific tissues and optimizing material porous structures are central goals for improving biomaterials. However, biomaterials with both precision-controlled porous structures and brain-matched mechanical properties (low modulus) are still lacking. In this study, we developed soft hydrogel scaffolds with mechanical properties similar to that of CNS tissues, and a uniform 40 µm porous structure—40 µm pores have been shown to be optimal for healing in many tissues. The two characteristics were achieved by a new fabrication process combining phase separation and sphere templating. The resulting scaffolds are non-cytotoxic according to the ISO 10993-5 standard. In addition, the three-dimensional culture of microglial cells within the scaffolds demonstrates cell attachment and maintenance of a rounded, quiescent morphology, potentially due to spatial confinement. These results justify further in vivo studies and suggest broad potential in CNS applications, such as brain-computer interfaces, neural regeneration, and basic neurobiology. Subject classification codes: Neural Interfaces, soft hydrogel, synthetic biomaterials