This book offers an in-depth exploration of cutting-edge applications of nanoscience, microtechnology, and nanotechnology across health, environment, energy, materials, and food sectors. Organized into two sections—comprehensive reviews and original research—it covers topics such as active and intelligent food packaging, carbon foams from lignocellulosic biomass for wastewater treatment within a circular economy framework, and nanostructured hydrogels derived from residual biomass for medical, agricultural, and food uses. The research section highlights innovations including agronanofungicides to combat Fusarium spp. in corn, alginic acid hydrogels for tissue regeneration, nanocoatings for pepper preservation, SiO2 and Fe3O4 nanomaterials for hyperthermia and controlled drug release, and cytotoxicity studies of plant extracts in nanoencapsulated forms. Together, these contributions provide a comprehensive reference on emerging trends and practical advances in nanomaterials for diverse application