Magnetically Actuated Coscinodiscus radiatus-Based Microrobots with Concurrent High Mechanical Strength and Excellent Biodegradable Properties

Precise cell delivery using magnetically actuated microrobots is critical in the field of tissue regeneration. However, existing microrobot carriers struggle to simultaneously achieve both high mechanical performance and biodegradability. This study proposes a microrobot based on Coscinodiscus radiatus (CRs), termed magnetized Coscinodiscus radiatus (M-CRs), fabricated by acidification and magnetization of CRs. Experimental studies demonstrate that M-CRs exhibit excellent degradation properties, degrading over 85% within in Phosphate-Buffered Saline (PBS), which simulates the physiological fluid environment. Additionally, M-CRs possess high mechanical strength, with experiments showing the average Young’s modulus of their surface can reach 77 MPa, significantly higher than typical biodegradable materials. Furthermore, the proposed microrobots features a regular porous structure that provides anchor points for cell loading. Using a magnetic tweezer system, the microrobots move to target positions. In vitro experiments confirm that M-CRs have strong loading capacity and stable locomotion, moving along predetermined trajectories in complex environments. M-CRs meet both high mechanical strength and biodegradability requirements, providing a technological solution for cell delivery and tissue regeneration.