A Neurospheroid‐Based Microrobot for Targeted Neural Connections in a Hippocampal Slice

• Published in: Advanced materials (Weinheim) 2023-03, Vol.35 (13), p.e2208747-n/a
• Main Authors: Kim, Eunhee, Jeon, Sungwoong, Yang, Yoon‐Sil, Jin, Chaewon, Kim, Jin‐young, Oh, Yong‐Seok, Rah, Jong‐Cheol, Choi, Hongsoo
• Format: Article
• Language: English
• Subjects: Cell- and Tissue-Based Therapy; high‐density multi‐electrode arrays; Hippocampus - physiology; In vivo methods and tests; Magnetic Fields; magnetic manipulation; Magnetite Nanoparticles - chemistry; Materials science; Microrobots; Nanoparticles; Neurons; Neurons - physiology; neurospheroids; organotypic hippocampal slice; Regenerative Medicine; superparamagnetic iron oxide nanoparticles; Transplantation
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202208747

Functional restoration by the re‐establishment of cellular or neural connections remains a major challenge in targeted cell therapy and regenerative medicine. Recent advances in magnetically powered microrobots have shown potential for use in controlled and targeted cell therapy. In this study, a magnetic neurospheroid (Mag‐Neurobot) that can form both structural and functional connections with an organotypic hippocampal slice (OHS) is assessed using an ex vivo model as a bridge toward in vivo application. The Mag‐Neurobot consists of hippocampal neurons and superparamagnetic nanoparticles (SPIONs); it is precisely and skillfully manipulated by an external magnetic field. Furthermore, the results of patch‐clamp recordings of hippocampal neurons indicate that neither the neuronal excitabilities nor the synaptic functions of SPION‐loaded cells are significantly affected. Analysis of neural activity propagation using high‐density multi‐electrode arrays shows that the delivered Mag‐Neurobot is functionally connected with the OHS. The applications of this study include functional verification for targeted cell delivery through the characterization of novel synaptic connections and the functionalities of transported and transplanted cells. The success of the Mag‐Neurobot opens up new avenues of research and application; it offers a test platform for functional neural connections and neural regenerative processes through cell transplantation. Using an external rotating magnetic field, a magnetic neurospheroid consisting of primary hippocampal neurons and superparamagnetic nanoparticles can be precisely delivered to the target area in an ex vivo brain slice, where the neurospheroid subsequently establishes structural and functional neuronal connectivity. This method can be used to examine ex vivo functional neuronal connections and neuronal regeneration processes.