Preparation and swelling properties of pectin/poly (vinyl alcohol)composite hydrogel for prosthetic nucleus pulposus

The pectin/poly (vinyl alcohol) composite (CoPP) hydrogel was prepared by low f requency oscillation
and freezing-thawing. The structure of CoPP hydrogel was characterized by FTIR, DSC, XRD and SEM, the swelling properties were observed, and the diffusion of water and the swelling dynamics were also discussed. The experimental results show that CoPP hydrogel is porous, and has two kinds of crystal regions. The diffusion characteristic index which water molecule immerses into CoPP hydrogel was near 0. 5, which indicates the diffusion is in Fick model. The swelling velocity constant of CoPP, the swelling ratio of mass (197. 38 %～252. 49 %) and swelling ratio of volume (241. 47 %～308. 93 %) of CoPP at the swelling equilibration were superior to those of poly (vinylalcohol) (PVA) hydrogel. Therefore, the swelling properties of CoPP composite hydrogel are faster and larger, which makes it possible to implant the artificial nucleus pulposus prosthesis in smaller size with the minimally invasive surgery.