Toward a New Generation of Bio-Scaffolds for Neural Tissue Engineering: Challenges and Perspectives

Abstract

Neural tissue engineering presents a compelling technological breakthrough in restoring brain function, holding immense promise. However, the quest to develop implantable scaffolds for neural culture that fulfill all necessary criteria poses a remarkable challenge for material science. These materials must possess a host of desirable characteristics, including support for cellular survival, proliferation, and neuronal migration and the minimization of inflammatory responses. Moreover, they should facilitate electrochemical cell communication, display mechanical properties akin to the brain, emulate the intricate architecture of the extracellular matrix, and ideally allow the controlled release of substances. This comprehensive review delves into the primary requisites, limitations, and prospective avenues for scaffold design in brain tissue engineering. By offering a panoramic overview, our work aims to serve as an essential resource, guiding the creation of materials endowed with bio-mimetic properties, ultimately revolutionizing the treatment of neurological disorders by developing brain-implantable scaffolds.

Injectable Hydrogels for Nervous Tissue Repair—A Brief Review

“…The mechanical properties of scaffolds are essential for neural tissue engineering, as the brain is the softest organ in the body. Scaffolds must mimic the mechanical properties of the brain with adequate stiffness to allow for cell attachment [ 18 ]. For example, the mechanical stress experienced by the neuronal membrane along the scaffold surface interface dictates axonal growth and directionality [ 19 ].…”

“…Topography is crucial in favoring neurite attachment. For example, nanostructured surfaces that mimic the architecture of the extracellular matrix can favor cell propagation, proliferation, adhesion, neurite extension and branching, migration, and electrical signal transmission, while topography influences neural stem cell differentiation [ 18 ]. Previous studies have shown that neural cells can align and elongate in the direction of aligned nanofibers more clearly than those grown on random nanofibers [ 17 ].…”

“…The polymeric structure of a scaffold must immobilize molecules within the core of the material, such as antibiotics, anti-inflammatory drugs, growth factors, and neurotrophic factors [ 18 ]. In addition, the scaffold must have an adequate topography, porosity, and pore size for cell adhesion and for the diffusion of residues, nutrients, and growth factors into the polymeric porous structure [ 20 ] ( Figure 1 ).…”

“…Therefore, biodegradable scaffolds aid nerve cell proliferation before being dissolved by the body while healing occurs [ 20 ]. Ideally, these scaffolds must possess electrical conductivity, facilitating interneuronal communication [ 18 ].…”

“…Therefore, biodegradable scaffolds aid nerve cell proliferation before being dissolved by the body while healing occurs [20]. Ideally, these scaffolds must possess electrical conductivity, facilitating interneuronal communication [18]. Hydrogels are a promising class of biomaterials produced by natural and synthetic polymers with high water content, high porosity, and mechanical properties like those of native tissue [22][23][24].…”