Engineering Smart Polymeric Nanosystems for Multi- Targeted Drug Delivery in Chronic Diseases

Abstract

Chronic diseases including cancer, diabetes mellitus, cardiovascular disorders, and neurodegenerative conditions constitute the leading cause of global morbidity and mortality, yet their pharmacological management remains constrained by the non-specific biodistribution, poor bioavailability, and systemic toxicity inherent to conventional drug delivery systems. Over the past two decades, polymeric nanosystems have emerged as a transformative platform capable of encapsulating diverse therapeutic payloads, controlling release kinetics, and navigating complex biological barriers. The concept of "smart" nanosystems extends this paradigm further: by integrating stimuli-responsive moieties sensitive to pH, temperature, redox gradients, or enzymatic activity these carriers can achieve spatiotemporal precision in drug release that conventional systems cannot approximate. Multi-targeted strategies, combining passive accumulation via the enhanced permeability and retention (EPR) effect with active ligand– receptor recognition and intracellular delivery mechanisms, offer the prospect of simultaneously addressing multiple pathological pathways within a single nanoscale architecture. This review synthesizes the current literature on the design, engineering, preparation, and characterization of smart polymeric nanosystems, and critically evaluates their therapeutic applications across major chronic diseases. We examine recent advances including AI-assisted polymer design, theranostic integration, and hybrid nanocarrier architectures, while honestly appraising the translational challenges of scale-up manufacturing, regulatory complexity, and clinical validation. Looking forward, the convergence of smart polymeric nanotechnology with personalized medicine, gene therapy, and bioelectronics portends a paradigm shift toward truly adaptive, patient-specific therapeutic systems.