Figure 3.

Analysis of the rheological properties and developing a correlation between the rheological properties of the hydrogel ink with intermolecular networking between the nanohydroxyapatite with alginate/gelatin. (a) The schematic represents the mechanical interlocking phenomenon inside the hydrogel-based components responsible for maintaining the pseudoplastic and viscoelastic properties of the hydrogel ink. (b) Pseudoplastic/shear-thinning behavior of the synthesized hydrogel ink. Panels (c–e) show the evaluation of the linear viscoelastic regime (LVR) of the hydrogel ink by amplitude sweep by observing the variation of storage modulus (G′) and loss modulus (G″), with respect to shear stress and shear strain and to find the crossover region. (f, g) Analysis of the strength of the synthesized hydrogel ink through frequency sweep by observing the variation of storage modulus (G′), loss modulus (G″), and tanδ with respect to frequency. (h–j) Analysis of gel stability with respect to temperature by observing the variation of storage modulus (G′), loss modulus (G″), loss factor (tan δ), and viscosity with respect to temperature in a temperature window including the physiological temperature window. Panels (k, l) represent the evaluation of gel stability with respect to time by observing the linearity of storage modulus (G′), loss modulus (G″), and loss factor (tan δ) with respect to time up to 4 h. (m) The analysis of shape recoverability, i.e., the thixotropic behavior of the synthesized hydrogel ink.