Fibers are among the most versatile material forms in contemporary applications, including textiles, biomedicine, and aerospace. Wet spinning, the process of coagulating a polymer solution into tangible fibers, remains one of the oldest and most reliable methods to fabricate fibers continuously from a wide range of materials. Contemporary research in fiber science has begun to re-imagine filaments as environmentally-responsive materials, capitalizing on novel classes of polymers and nanomaterials to amplify sensing, electrical, and mechanical properties. A promising class includes anisotropic organic materials, including cellulose nanofibers, liquid crystal (LC) molecules and polymers, which can offer distinctive processability and structural advantages with tunable intermolecular interactions such as π − π stacking and hydrogen bonding. In this thesis, we focus on the controlled assembly and processing of anisotropic building blocks, from thermotropic LC monomers to aramid nanofibers, for preparation of responsive filaments. In understanding their interactions and ordering, we formulate and design wet spinning processes to scalably fabricate thermoresponsive filaments towards applications in active textiles, artificial muscles, and atmospheric water harvesting (AWH). We first design a one-way diffusion-based wet spinning system to fabricate LC elastomer (LCE) filaments up to 12 m h-1. Next, we formulate a nematic spinning dope by mixing LC monomers with LC solvents to wet-spin filaments, followed by post-manufacturing crosslinking. Capitalizing on textile structuring and assembly, the filaments demonstrate contraction- and twisting-based actuation behaviors up to 31% in strain and 21 revolutions, respectively. The wet-spun filaments are plied and embroidered in commercial fabrics to create active, or environmentally-responsive, textiles with diverse locomotions. Further, we design a double-diffusion wet spinning process to fabricate graphene/LCE composite filaments, where thermotropic LC oligomers are used as the building blocks. Graphene nanosheets are introduced to amplify π − π stacking of the benzene rings, allowing for the formation of stable filaments with tunable diameters ranging from 137 to 1128 μm, at fabrication speeds up to 4500 m h-1. The wet-spun graphene/LCE filaments can reach actuation strains up to 44% within 3 s. With graphene/LCE filaments across various diameters, we demonstrate the locomotion of the filaments towards artificial muscles such as biceps and quadriceps. Finally, we extend the double-diffusion wet spinning technique to fabricate aramid nanofiber (ANF)- templated hybrid hydrogel desiccants at a speed of 61 m h-1. Using ANFs as the building blocks, we template the thermoreponsive polymer, hydroxypropyl cellulose (HPC), in an aqueous coagulation bath containing lithium chloride (LiCl) to yield filaments capable of moisture capture. In arid conditions (∼30% relative humidity), the hybrid hydrogel desiccant fibers can capture up to 0.55 g of water per g of dried filament within 40 min and release ∼72% of captured water within 30 min at 60 °C. The hybrid hydrogel desiccant filaments are integrated into an AWH chamber to achieve a water collection of 0.27 g g-1 within 75 min (45 min sorption, 30 min desorption/collection). By synergizing nanomaterials’ environmental responsiveness, assembly, and wet spinning processes, our studies outline design strategies for wet spinning towards the next generation of responsive fibers and textiles.