Advances in the mechanisms of fibrosis at the electrode interface of invasive brain-computer interfaces and intervention strategies

The invasive brain-computer interface (BCI) is a method that involves implanting microelectrodes into brain tissue to collect neural electrical signals. The signals obtained through this method are often of high precision and relatively stable. However, the chronic fibrotic reaction resulting from long-term implantation can significantly impair the quality of the collected brain electrical signals. Therefore, ensuring the long-term stability of signal acquisition is a major challenge in the development of invasive BCI. This paper systematically reviews the formation mechanisms of fibrosis at the electrode interface, elaborating on the progression from acute inflammatory responses to the development of chronic glial scars and the formation of the extracellular matrix (ECM). It introduces the roles, advantages, and disadvantages of three anti-fibrosis strategies: material and surface optimization, drug and biological factor intervention, and integration of immune regulation and tissue engineering. This paper also evaluates their practical effects and limitations in animal and human clinical applications. Finally, it highlights the importance of establishment of standardized follow-up recording mechanisms in ensuring the long-term reliability and stability of invasive BCIs, providing references and insights for future in-depth interface optimization and clinical translation.