Nanofiber-based Biodegradable Multi-legged Millirobot

Description

Soft millirobots that can leverage controllable drug delivery is of great interest for future biomedical applications owing to their features in tiny size, soft nature, and untethered control. Although recent success in sophisticated multimodal locomotion, however, the biodegradability and programmable drug release capacities of millirobot remains a big challenge. Such issue has been the major bottleneck of further applying the millirobot in practice in biomedical engineering, especially for the latest combination therapy, which is advocated as a cornerstone for various diseases medical treatments, e.g., ulcerative colitis, colorectal cancer, type 2 diabetes mellitus, and wound healing. This project aims at proposing a nanofiber-based, magnetically powered, pH-responsive, and biodegradable soft millirobot (Fibot) to address the stepwise combination therapy. Distinct from the conventional methods, we intend to develop a bottom-up magnetic field assisted electrospun platform to construct the Fibot with a soft membrane body and multi-legs. Here, both the soft body and the tapered legs will be fabricated from non-cytotoxic biodegradable materials (Eudragit L100 and Eudragit S100 for the nanofiber-based membrane; Eudragit L100-55 and iron microparticles for the legs) and different drugs can be embedded in the body and legs during the fabrication process simultaneously. By adjusting the material ratio of the body and legs, we can controllably degrade them at different pH values, offering a solution for the stepwise combination therapy. The iron microparticles embedded legs will allow the Fibot to be actuated effectively by external magnetic, via which the Fibot can achieve multimodal locomotion and adapt to the harsh bio-environment. After verifying the biodegradable and locomotion ability of the Fibot, we will design the in vitro experiment to test the stepwise combination therapy ability of the Fibot, including the bacteriostatic therapy, alimentary cancer against, and so on. Compared with the state-of-arts, our proposed method will provide a new insight for biodegradable soft millirobot design and fabrication. The Fibot with lower limbs and membrane body will yield versatile locomotion ability at harsh bio-environment, programmable stepwise degradation, and drug release ability response to the variation of acidic physiological concentrations. The robot’s biocompatibility/biodegradability and precise locomotion control offers great opportunity for several kinds of disease therapy, such as tumor and thrombectomy, which is expected to generate long-term impact in robotic as well as biomedical engineering field.