Chemical materials involved in neural tissue engineering scaffold techniques: a narrative review

Nerve injury often leads to degeneration or necrosis of damaged nerve cells, which can result in regeneration disorders during the repair process. Promoting nerve regeneration is a critical challenge in the treatment of nervous system diseases. With rapid advancements in related research, chemical materials have shown significant promise in facilitating nerve regeneration because of their excellent biocompatibility and degradability. The use of tissue-engineered chemical material scaffolds can provide physical channels for nerve regeneration. These scaffolds can create optimal conditions for cell growth and migration and effectively regulate physiological processes during nerve repair. Therefore, chemical materials have a wide range of applications in the field of nerve regeneration. This review highlights the technological tools available for nerve regeneration and repair involving chemical materials. (1) Conductive hydrogels: Novel conductive hydrogels have been developed by integrating conductive materials such as graphene, carbon nanotubes, and polypyrrole, which can promote the growth and functional recovery of nerve cells through electrical stimulation. (2) Three-dimensional printing: Three-dimensional printing technology contributes to precise control of the shape, porosity and degradation rate of the scaffolds, providing a customized microenvironment for nerve regeneration. (3) Nanomaterials: The unique physicochemical properties of nanoparticles and nanofibers give them great potential to penetrate the blood‒brain barrier, guide nerve growth and provide targeted drug delivery. (4) Local release of bioactive molecules: Through the design of chemical materials, the controlled release of bioactive molecules such as nerve growth factor, brain-derived neurotrophic factor and fibroblast growth factor has been realized, which effectively promotes nerve regeneration. (5) Photothermal and photoacoustic stimulation: The combination of photothermal and photoacoustic technologies has led to the development of nerve regeneration materials capable of responding to photostimulation, providing new avenues for noninvasive neurostimulation. These new technological tools for nerve engineering involving chemical materials are highly effective in promoting nerve regeneration and can significantly improve the efficiency and quality of nerve repair. In clinical practice, these techniques are expected to provide more effective strategies for patients with nerve injuries, improving their function and quality of life. This review also discusses in detail the properties of different chemical materials, such as their biocompatibility, mechanical strength, and degradability, which are critical for nerve regeneration. A variety of chemical materials have been shown to promote nerve cell regeneration through neural tissue engineering scaffold techniques, including the provision of physical support, release of bioactive molecules, and direct interaction with nerve cells. Although these new technological tools show great potential, several challenges, including biocompatibility, long-term stability, individual variation in response, and large-scale production, still need to be addressed before they can be translated into clinical applications. In addition, a comprehensive assessment of the long-term safety and efficacy of these materials is also a focus of future research. Future research will focus on improving the biocompatibility of the materials, optimizing the material design and conducting large-scale clinical trials to validate the safety and efficacy of these chemical materials in neural tissue engineering scaffold techniques.