Viscoelastic properties of a novel hydrogel/foam composites for nucleus pulposus replacement

Abstract

Neck and back pathologies cause considerable pain and suffering, and treatment costs tens of billions per year. A common source of problems is degeneration and herniation of the gel-like nucleus pulposus (NP) component of the intervertebral disc, and NP repair/replacement has been a long-term health care goal. We have investigated a novel class of hydrogel/foam composites to identify biocompatible materials with similar viscoelastic characteristics to the native tissue. Low acyl gellan gum (G) and agarose (A) in varying weight percentages were infused into Sugi® cellulose sponge material (F) to produce three candidate materials in addition to those samples without foam. Dynamic oscillatory shear tests and dynamic oscillatory axial compression test tests were conducted on the materials at frequencies between (f = 0.1-10 Hz) to measure elastic (storage) and viscous (loss) moduli in shear and compression conditions. The results show that hydrogel/foam composites show greater viscoelastic properties than hydrogel alone. Various materials of hydrogel and hydrogel/foam composite closely match the viscoelastic properties of native NP tissue.

Developing a novel functional disc emulator to investigate the nucleus pulposus replacement

“…Agarose (IBI Scientific, IA, USA) was used for the NP component as a generic hydrogel analogue [ 23 ], as shown in (Fig. 1C ).…”

Decellularized Nucleus Pulposus Matrix/Chitosan Hybrid Hydrogels for Nucleus Pulposus Tissue Engineering

“…However, the hydrogel generally has poor mechanical properties, which limits its application. 11 Chitosan could make up for this disadvantage. 12 Additionally, the structure of chitosan is similar to glycosaminoglycan, the main component of the NP.…”

Experimental investigation of the effects of infusing a foam into hydrogels on the hyperelastic coefficients

“…Hydrogels are three‐dimension cross‐linked networks highly utilized as a tissue scaffold. For instance, agarose, low acylgellan gum, and alginate were used as a promising material for nucleus pulposus (NP) replacements 1 because they exhibited viscoelastic behavior, and their mechanical behavior resembles the native tissue such as the NP 2 . Because hydrogels show a nonlinear behavior under mechanical compression test, it is important to understand their mechanical behavior out of the test range by adapting the hyperelastic models such as Ogden, Neo‐Hookean, Mooney‐Rivlin, and Yeoh models.…”