Assessing the applicability of tunicate skin-extracted cellulose as a base material for ultrasound gel

Cellulose is widely considered an outstanding biomaterial due to its remarkable ionic properties, exceptional biocompatibility, and low toxicity. Its abundant surface hydroxyl groups facilitate increased hydrogen bonding, improving gelation and swelling capabilities. Moreover, incorporating carboxymethyl groups enhances solubility and allows for diverse formulations, serving as multifunctional cross-linkers. Among the various sources of this compound, tunicate-derived cellulose is an animal-derived cellulose and food byproduct with low utility. However, recycling tunicate skin into a useful biomaterial would provide access to the unique characteristics of animal cellulose, distinct from those of plant-derived cellulose. Particularly, tunicate cellulose has a longer fiber length than plant cellulose, enhancing the sound propagation speed within the material and making it suitable for the production of ultrasound-responsive gels. This study examined the viscosity and conductivity of tunicate-derived carboxymethyl celluloseto assess its applicability as an ultrasound gel. Additionally, small molecule release after ultrasound stimulation was also evaluated.