Preliminary studies on the in vivo performance of various kinds of nanocellulose for biomedical applications

Abstract

Nanocellulose has recently attracted a great deal of attention for numerous biomedical applications due to its superior mechanical properties, high surface area, tailorable surface chemistry, good biocompatibility, renewable nature, and cost-effectiveness. The objective of this study was to investigate the long-term in vivo biocompatibility of three kinds of nanocellulose, namely, cellulose nanocrystal (CNC), cellulose nanofiber (CNF), and TEMPO-oxidized cellulose nanofiber (TOCNF). The morphological features of these nanocellulose materials were examined by transmission electron microscopy. In vivo biocompatibility of all nanocellulose materials was investigated using a subcutaneous rat model for 1, 2, 4, and 12 weeks of implantation. The average diameters of prepared homogenous CNC, CNF, and TOCNF were ∼6 nm, ∼8 nm, and ∼5 nm respectively, as depicted by micrographs obtained by using transmission electron microscopy. TOCNF showed highest in vitro biocompatibility with respect to CNC and CNF in response to L929 fibroblast cells. In vivo studies revealed that all nanocellulose materials exhibited no foreign body reaction up to two-week post-injection. Subcutaneous implantation at 12 weeks showed lowest inflammation and better tissue repair for TOCNF compared to CNC and CNF. The results suggest that the long-term biocompatibility profile follows the sequence: TOCNF > CNC > CNF.