Target organs and progression of neuromodulation technologies to control metabolic functions. Neuromodulation can be categorized based on the peripheral target innervated by the circuit or nerve stimulated. a. Target organs that regulate metabolism are innervated by afferent and efferent fibers that release neurotransmitters or paracrine signals which modulate the organ’s function and greatly impact local and systemic metabolisms. b. Pharmaceutical interventions for T1D. Blood glucose level is self-measured, and insulin is injected via syringe multiple times daily. Closed-loop advanced drug delivery systems greatly improve disease management outcomes and patients’ life quality. c. DBS and VNS systems for bioelectronic medicine require implanted stimulators that generate electrical pulses. They are then connected by wires to microelectrodes implanted in the brain or on the vagus nerve. d. Using a hydrogel-based micro-TENN as scaffold , neuronal networks can be rationally designed and transplanted to innervate and/or replace living tissues. An autologous β-cell biocircuit concept consists of ACh releasing neurons inside a micro-TENN with directed innervation into vascularized, mature and encapsulated β-cell clusters derived from patient’s iPSCs. Image courtesy of Anthony S. Baker and Courtney Fleming, The Ohio State University© 2019; produced with permission.