Porous Gelatin Hydrogels Based on Clay Promoted by Calcium Mineralization

A bioclean method was proposed to prepare porous gelatin-based hydrogels using clay as porogen, water as solvent and calcium as promoter: firstly, laponite clay and gelatin were individually dissolved in deionized water to get aqueous solutions; then the two solutions were blended and exposed to -20°C for 24 h to form physically crosslinked hydrogel; finally the hydrogel was soaked in a calcium chloride solution at room temperature for 48 h to obtain matrixes with well-defined voids. The gelatin molecules intercalated into the clay slices gaining uniform composites, which were confirmed by atomic force microscopy, infrared spectrum, X-ray diffraction and differential scanning calorimetry analyses. As proved by scanning electron microscopy study, in the matrix containing 5% gelatin and 2% clay, the voids were interconnecting, and the size of pores focused on a range of 100-200 μm. Such matrix might serve as scaffolds for tissue engineering because of its typical pore structure and size distribution. Additionally, such material could be used as wound dressings, for it was able to provide a fine moist environment for a surface.