Programmable Electrodeposition of Janus Alginate/Poly‐L‐Lysine/Alginate (APA) Microcapsules for High‐Resolution Cell Patterning and Compartmentalization

Abstract Encapsulation of live cells in protective, semipermeable microcapsules is one of the kernel techniques for in vitro tissue regeneration, cell therapies, and pharmaceutical screening. Advanced fabrication techniques for cell encapsulation have been developed to meet different requirements. Existing cell encapsulation techniques place substantial constraints on the spatial patterning of live cells as well as on the compartmentalization of heterotypic cells. Alginate‐Poly‐L‐lysine‐alginate (APA) microcapsules that use sodium alginate as the polyanion and poly‐L‐lysine (PLL) as the polycation have been extensively employed for cell microencapsulation due to their excellent biocompatibility and biodegradability. This study proposes a novel method for developing programmable Janus APA microcapsules with variable shapes and sizes by using electrodeposition. By the versatile design of the microelectrode device, sequential electrodeposition is triggered to electro‐address the cells at specific locations immobilized within a Janus APA microcapsule. The osteogenesis is evaluated by resembling cell compartmentalized and vascularized osteoblast‐laden constructs. This technique allows precise spatial patterning of heterotypic cells inside the APA microcapsule, enabling the observation of cellular growth, interactions, and differentiation in a well‐controlled chemical and mechanical microenvironment.