Structure–Function Tuning of Lyotropic Liquid Crystal-Carbon Nanotube Composites for Drug Delivery

Incorporating carbon nanotubes (CNTs) into polymeric hydrogels significantly expands their functional capabilities in biomedical applications. By improving printability and regulating drug release, CNTs enable the 3D printing of these hydrogels into custom geometries tailored to complex wound beds. Functionalized CNTs are dispersible in solvents and have polar and nonpolar sites that can interact with the polymer, possibly affecting its structure. This study was designed to investigate this phenomenon with a photo-cross-linkable diacrylated Pluronic F127 (DA-F127) utilized as a model able to self-assemble into lyotropic liquid crystal (LLC) phases. Micellar cubic (Mic) and hexagonally ordered fibrillar (Fib) phases were mixed with two types of covalently functionalized CNTs. The structural and functional properties of the nanocomposites were investigated for potential applications: 3D-printable inks, drug-delivery scaffolds, and wound dressings. The aim was to provide a guideline for the optimal pairing of the compounds. Amide-modified CNTs performed optimally in the Fib phase, whereas oxidized CNTs were best suited for the Mic phase. Proper pairing resulted in improved printability and drug release profiles while maintaining the LLC phase ordering, whereas using CNTs in the opposite combinations disrupted the LLC order.