ABSTRACT
We report the development of halloysite nanotubes (HNTs)/carboxylated-cellulose nanocrystals (cCNCs) - reinforced and ionically-crosslinked k-carrageenan (k-CG)/xanthan gum (XG) hydrogels. In this study, cCNCs were extracted from microcrystalline cellulose using ammonium persulfate and exhibit 'spindle-like' nanocrystals with approximate diameter of 15-30â¯nm and length of 30-120â¯nm. The freeze-dried hydrogels showed highly porous microstructure with good pore-interconnectivity. Further, tunable swelling ratio and in vitro degradation rate of hydrogels under physiological condition (pHâ¯7.4 PBS, 37⯰C) were observed. In wet or dry states, the dynamic mechanical analysis of kCXGHN20cCN20 hydrogel showed significantly improved compressive strengths (at 50% strain: 8.1⯱â¯1.35â¯kPa or 81.33⯱â¯1.66â¯kPa, whereas at 70% strain: 11.84⯱â¯0.61â¯kPa or 120.7⯱â¯1.16â¯kPa) when reinforced with HNTs (20â¯wt%)/cCNCs (20â¯wt%), respectively. The stiffness values are reported at different compressive strains. All hydrogels showed excellent attachment and proliferation of human skin fibroblasts (CCD-986Sk) cells on hydrogels for 7 and 14â¯days of culture periods. The results showed that these hydrogels may have potential application in soft tissue engineering.