The Effect of Composite Components on the Shear Stresses Generated During Injection of Shear-Thinning Guest-Host Hydrogels

Shear-thinning hydrogels can be combined with other components to enable multi-functionality, including short fibers or particles [1]. For the inclusion of fibers, electrospinning has gained momentum as a simple technique to create tissue engineered scaffolds that mimic the fibrous nature of the extracellular matrix [2]. Combining electrospun fibers with a shear-thinning hydrogel has the potential to provide cells with essential physical cues while retaining injectability [3]. Cells do not adhere well to hyaluronic acid alone, thus, peptides or fibers can be incorporated into the hydrogel mixture to improve cell adherence and facilitate better cell-material interactions [1,4]. In the future, hydrogel composite systems including fibers and/or peptides can be manufactured using shear-thinning hydrogels as an ideal multi-functional, injectable hydrogel for tissue repair applications. To establish the effect of these components on composite injectability, injection force experiments were conducted to quantify break and glide force. There was no statistically significant difference in break force of Ad-MeHA + CD-HA guest-host hydrogels of 5 wt%, 6 wt%, 6 wt% with peptides, and 7 wt% HA. A significant difference (p < 0.001) in glide force of Ad-MeHA + CD-HA guest-host hydrogels between 5wt% and 7wt% was observed. There was no statistically significant difference in break force or glide force of Ad-MeHA + CD-HA 7 wt% guest-host hydrogels of 0, 0.5, or 1 wt% fibers (40 µm, 15% SPIONs).