Soft, Degradable, and Magnetic Microcarriers for Encapsulation and Guided Transport of Drugs and 3D Spheroids

Soft microcarriers hold great potential for biomedical applications, yet their translation is limited by the lack of controlled degradation, restricted capacity for co-encapsulation of therapeutic and cellular cargos, long-term biocompatibility, and scalable production challenges. Here, we introduce a new concept of discrete, degradable hydrogel microcarriers, produced via droplet-based microfluidics and UV photopolymerization, designed to integrate these properties. These soft microcarriers enable co-encapsulation of multiple species, including magnetic particles, drugs, and living cell spheroids, while allowing precise motion control over complex trajectories using external gradient magnetic fields. Their tunable degradation under physiological conditions ensures transient stability, controlled navigation, and safe clearance. This approach provides spatiotemporal control over cargo transport and release, enabling the microcarriers to function as systems with a controllable lifecycle. These multifunctional microcarriers represent a versatile platform for tissue engineering, minimally invasive therapies, and diagnostic monitoring, enhanced by the precise in situ navigation option.