Preparation of xanthan gum-based composite hydrogels with aligned porous structure

Aligned hydrogels have received increasing attention in tissue engineering and electrochemical fields due to their favorable structure. In this work, xanthan gum-based hydrogels (XGH) with aligned pores were prepared via photoinitiated free radical irradiation that used sodium acetate crystals as template. The microstructure, compressive strength, porosity, and absorption capacity of the hydrogel were studied and compared with the non-aligned hydrogels. Scanning electron microscope analysis confirmed the aligned porous structure of the hydrogel. The maximum compressive strength for the aligned hydrogel prepared with 12% acrylamide and 1.5% xanthan gum reached 0.439 MPa at a strain of 95%. Furthermore, aligned XGH exhibited better flexibility than non-aligned hydrogels, as indicated by the Young’s compressive modulus. The porosity of the aligned hydrogels ranged from 94.9% to 88.8% as the acrylamide concentration increased from 12% to 20%. Simulated body fluid absorption showed that hydrogels with aligned pores could attain absorption equilibrium within 5 min, and the maximum absorption capacity reached 33.6 g/g for the sample made with 0.5% xanthan gum and 12% acrylamide. In addition, exhibited preferable biocompatibility, as demonstrated by the cytotoxicity test.