This volume brings together cutting-edge research on polymers, composites, nanocomposites, and biocomposites, highlighting both fundamental breakthroughs and real-world applications. The chapters cover a wide spectrum of innovations—from self-healing cementitious composites for resilient infrastructure and nanotechnology-enabled smart textiles to high-performance hybrid polymers engineered for enhanced strength and durability.A strong emphasis is placed on sustainability, with contributions exploring chitosan-based films for dye removal, microbial strategies for soil bioremediation, and bio-derived polymers such as zein that reduce reliance on non-renewable resources. Equally significant are the advances in biomedical applications, including next-generation dental polymers, scaffolds for nerve regeneration, and bioinspired materials that combine mechanical robustness with biological function.By bridging materials science, biotechnology, and clinical perspectives, this collection illustrates how next-generation biomaterials are driving solutions to global challenges in healthcare, industry, and environmental protection. Offering both depth and accessibility, it serves as a valuable reference for researchers, clinicians, graduate students, and professionals worldwide.