Multi-Scaled Cellulosic Nanonetworks from Tunicates

The selective removal of non-cellulosics from microbial biofilms and particularly plants has enabled the formation of high-performance yet sustainable functional materials. However, ascidians, the only animals to synthesize cellulose nanofibers, have not been explored for their cellulosic nanonetworks. In this work, the removal of non-cellulosics from ascidians through mild processes yields a cellulose nanonetwork with features that cannot be obtained from either plants or microbes. The obtained “nano-ascidian” has nanofibers structured into spherical capsules with a diameter of ≈50 µm bound by an extracellular matrix spanning across the entire tissue, which is convoluted with a 3D fractal network of capillaries ranging from 50 to 500 µm in diameter. The obtained nanonetwork is showcased for potential fluidics operation, highlighting domain-segregated infusion and functionalization by leveraging the vascularized structures present. Unique features associated with the innate cellulose-protein composition are put forward, including an outstanding strain at a break of 48%. Finally, the upcycling of ascidian into nanonetworks of cellulose as an ecosystem preservation tool for managing both native and invasive ascidian species is proposed. Overall, by providing a third-class, animal-based, of cellulosic nanonetworks, the study offers a new platform for advanced nanocellulosics uniquely associated with a global and sustainable coastal blue bioeconomy.