Preparation and characterization of borate bioactive glass cross-linked PVA hydrogel

Borate Bioactive Glass(BG)/PVA hydrogel was prepared by the combination of chemical cross - linking method and physical freeze-thawing method. BG powder and PVA solution were mixed at different BG/PVA weight ratios of 0.05, 0.10, 0.15 and 0.20 then went through freeze-thawing cycles to form the hydrogel. The BG/PVA hydrogels were characterized by swelling, degradability, drug delivery performance, mechanical strength, attenuated total reflection flourier transformed infrared spectroscopy (ATR-FTIR) and field emission scanning electron microscope with energy dispersive spectrometer (FESEM-EDS). The compressive strength and tensile strength of BG/PVA were improved compared to the pure PVA hydrogel. When immersed in PBS, all the hydrogels showed good swelling properties and the concentration of B released in PBS was smaller than 100 ppm due to the reaction with PVA and the release of functional ions could be detected by atomic emission spectrometer (ICP-AES). Therefore, this hydrogel showed excellent properties in both borate control and crosslinking.