Sperm-based microrobots for applications in assisted reproduction and drug delivery.

Untethered, self-propelled microrobots are a rapidly growing area of research withpromising applications in medicine, including diagnostics, targeted drug delivery, andminimally invasive procedures. Despite their potential, clinical translation remainslimited due to ongoing challenges in achieving reliable in vivo control, imaging, andbiocompatibility [1]. Among these, biohybrid microrobots, consisting of biologicalmaterials (i.e. cells) and synthetic materials, offer distinct advantages due to their biocompatibility and unique functions. Microrobots powered by highly motile sperm cells are especially interesting for applications in reproductive medicine due to their ability tooperate in complex biological environments. This talk presents the integration of live sperm cells with synthetic microstructures to create biohybrid micromotors capable ofautonomous movement and remote magnetic control. Different methods for the fabrication of suitable microstructures, coupling to sperm cells, and the operation by magnetic control are presented. These microrobots are explored in the context of reproductive medicine, where they offer potential for minimally invasive treatment of infertility through guided sperm delivery [2]. Furthermore, the use of sperm-driven microrobots for targeted drug delivery within the female reproductive tract opens newpossibilities for localized therapies in gynecological care [3]. By addressing challenges in guidance, scalability, and fluidic navigation, sperm-based microrobots offer a promising tool for future therapeutic strategies in reproductive health.

[1] M. Medina-Sánchez, O. Schmidt. Medical microbots need better imaging and control. Nature,545, 406–408 (2017)

[2] F. Striggow, C. Ribeiro, A. Aziz, R. Nauber, F. Hebenstreit, O. G. Schmidt, M. Medina-Sánchez. Magnetotactic Sperm Cells for Assisted Reproduction. Small, 20, 2310288 (2024)

[3] H. Xu, M. Medina-Sánchez, V. Magdanz, L. Schwarz, F. Hebenstreit, O. G. Schmidt. ACS Nano,12, 327–337 (2018)