Implantable and in-vivo shape-recoverable nanocellulose-hyaluronic acid composite hydrogel

Hydrogels have been used as a filling material in medical cosmetology, but current injection hydrogels have poor shaping ability due to its fluidity , while the hydrogels with fixed shape are easy to cause large wound size, resulting in rarely used in clinical practice. An implantable and in-vivo shape-recoverable hyaluronic acid (HA) based hydrogel is developed for tissue filling. In this work, complexes were made by hydrogen bonding between two natural polysaccharides : HA and TEMPO-oxidation cellulose nano-fiber. The elastic modulus of the HA/TOCN physical crosslinking hydrogel was maintained at 2500 G′ in Pa, while, when ethylene glycol diglycidyl ether was introduced in the hydrogel, the elastic modulus could reach 60,000 G′ in Pa. The volume of shrunk hydrogel reduced 80 ± 6 % of initial state, importantly, it can recover the shape in vivo inducing by extracellular moisture environment. Facts have proved that these shape recovery hydrogels were non-toxic to mammalian cells .