Sailee Chowdhury, Sithi Sarkar, Anirban Das, Koyel Kar, Priyanka Chakraborty
Closed-loop drug delivery systems represent a paradigm shift in personalized therapeutics, integrating real-time biosensing with responsive drug release to optimize treatment outcomes. This review outlines the fundamental concepts and mechanisms of closed-loop systems, tracing their historical evolution and highlighting primary design considerations for seamless integration. Advances in biosensor technologies, including electrochemical, optical, fluorescence-based, wearable, and implantable devices, enable accurate, real-time monitoring of physiological biomarkers, while AI and IoT-enabled platforms facilitate adaptive and predictive therapeutic control. Smart delivery platforms such as nanoparticles, micro- and nanorobots, hydrogels, polymeric systems, and wireless release devices offer precise, targeted, and controllable drug administration. Integration strategies leveraging feedback loops, real-time data acquisition, and bioelectronic interfaces are critical for achieving on-demand dosing. Clinical applications demonstrate significant potential across diabetes management, neurological disorders, cancer therapy, and cardiovascular and metabolic diseases, supported by FDA-approved systems and ongoing trials. Despite of such progress, challenges like biocompatibility, sensor fouling, miniaturization, power limitations, and regulatory concerns remain. Looking forward, the convergence of AI-driven predictive dosing, advanced biomaterials, and personalized closed-loop therapeutics promises to enhance regenerative medicine approaches, enabling safer, more effective, and individualized treatments. This review underscores the potential of biosensor-guided systems to revolutionize patient-centric drug delivery and foster the next generation of precision therapeutics.