Fabrication of Three-Dimensional Porous Keratin/PEO Biological Scaffolds

Abstract

In order to prepare the keratin biological scaffold, keratin was firstly extracted from human hair by immersing in 200mL of aqueous solution containing 7mol/L urea, 2wt% Sodium dodecyl sulfate (SDS), and 5wt% sodium disulfite (Na2S2O6). The mixture was then heated to 95°C, shaking for 4h, and filtered through a stainless-steel mesh, dialyzed against 3L of distilled water, with cellulose tubing having a molecular weight cutoff of 10000~14000Da for 36h and filtered again. To examine the property of keratin scaffold, the vacuum freeze-drying process of pure keratin was investigated to find the optimum process. In order to further improve the property of keratin scaffold, different contents of Poly Ethylene Oxide (PEO) were added into the keratin solution. The result showed that the optimum freezing process was that Freezing at room temperature for 4h, and then put the sample into the refrigerator from ambient temperature to-20°C for 4h. Then the sample was put into the cold trap for 24h at-56°C. During the last 4 hours, the vacuum pump was opened and the frozen temperature was raised gradually. The keratin scaffold with good mechanical properties and uniform porosity was fabricated when the concentration of keratin solution was 10wt%. Additionally, PEO plays an important role in improving the flexibility of keratin/PEO scaffold.