Magnetically driven biohybrid blood hydrogel fibres for personalized intracranial tumour therapy under fluoroscopic tracking.

Small materials with pliability and untethered mobility are particularly suitable for minimally invasive medical interventions inside the body. However, the capabilities and applicability of such soft 'robots' are restricted by foreign-body responses to them and by the need to get them cleared from the body after the intervention. Here we report the development of biodegradable magnetized biohybrid blood hydrogel fibres that evade immune recognition, and their applicability for targeted intracranial tumour therapy with real-time tracking through X-ray fluoroscopy. The gel fibres can be made of the patient's own blood mixed with a small amount of magnetic particles and can be produced in about 15 min. We show that the locomotion of intracranially injected gel fibres through cerebrospinal fluid can be remotely controlled under a magnetic field and fluoroscopically tracked, and that a drug encapsulated in the gels can be released on demand under magnetic control, as we show for the delivery of doxorubicin to intracranial tumours in the minipigs. Biodegradable soft actuatable materials that avoid foreign-body responses may aid the development of personalized targeted interventions.