| This paper has introduced the background, theory of the hydrogel, and the common hydrogel PVA and SA. We have optimized the concentration of the PVA, SA and CaCl2 by the preparation ways of dropping polyvinyl alcohol and sodium alginate mixture solution into calcium chloride solution, and detected the drying and swelling rate of the blend hydrogel beads. We have investigated its crystal degree by DSC, characterized its morphological property by SEM, and detected its opaque property by UV. The result of the concentration of the polyvinyl alcohol, sodium alginate and calcium chloride solution is 15%, 3.5% (wt%) and 0.1 mol/l (M), respectively, which can form the hydrogel beads with good properties. At the same time, it was found that which the blend hydrogel beads came through the freezing-thawing cycles depended on its bigger porous structure in its surface, faster drying rate, higher swelling ratio. The PVA and SA blend hydrogel also had good biocompatibility because of not using toxic crosslinker in the experiment process. Then we used the blend hydrogel to load the light-sensitive drug-Nifedipine, and detected the resolving concentration of the loading drug beads by immersing them into simulating gastric solution (0.1M HC1 solution), simulating intestinal solution (pH6.8, pH7.4 PBS (phosphate buffer solution)), and found that result is the hydrogel beads swelled the volume bigger and released the drug faster in pH7.4 PBS (phosphate buffer solution) than in 0.1M HC1 solution. We also revealed the novel result that the temperature, cycle and times of the freezing-thawing cycle can... |
