Magnetic soft microrobots for erectile dysfunction therapy.

Erectile dysfunction (ED) is a major threat to male fertility and quality of life, and mesenchymal stromal cells (MSCs) are a promising therapeutic option. However, therapeutic outcomes are compromised by low MSC retention and survival rates in corpus cavernosum tissue. Here, we developed an innovative magnetic soft microrobot comprising an ultrasoft hydrogel microsphere embedded with a magnetic nanoparticle chain for MSC delivery. This design also features phenylboronic acid groups for scavenging reactive oxygen species (ROS). With a Young's modulus of less than 1 kPa, the ultrasoft microrobot adapts its shape within narrow blood vessels, ensuring a uniform distribution of MSCs within the corpus cavernosum. Our findings showed that compared with traditional MSC injections, the MSC delivery microrobot (MSC-Rob) significantly enhanced MSC retention and survival. In both rat and beagle ED models, MSC-Rob treatment accelerated the repair of corpus cavernosum tissue and restored erectile function. Single-cell RNA sequencing (scRNA-seq) revealed that MSC-Rob treatment facilitates nerve and blood vessel regeneration in the corpus cavernosum by increasing the presence of regenerative macrophages. Overall, our MSC-Rob not only advances the clinical application of MSCs for ED therapy but also broadens the scope of microrobots for other cell therapies.