Application to Material for Cell Growth of Protain Hydorgel

生物材料通常以固态形式使用。用通常的脱胶方法得到的丝胶是低分子量的，它的膜非常脆，机械性能很差。本研究旨在获得坚韧的蚕茧膜，并研究蚕茧细胞生长与其表面性质的关系。首先，将蚕茧常规脱胶得到的丝胶与低相对分子质量、低皂化度的聚乙烯醇共混，然后将其注入蚕茧膜中。由于聚乙烯醇无定形链段与丝胶之间的分子相互作用，该膜具有良好的生物材料力学性能。其次，采用温和的提取条件(丝胶-B)制备了两种高分子量丝胶，即只在水中煮沸和使用一种新的富含丝胶的丝胶茧(丝胶-S)。水凝胶丝胶-B膜的力学性能优于常规脱胶丝胶膜，但不能作为水凝胶膜使用。而森森-S水凝胶膜为橡胶状。低分子量组分也包含在水凝胶膜中，因此在体温下浸泡在纯水中可以洗脱这一组分。浸泡5天后，洗脱完成，膜的机械性能减弱，尽管它可以在水凝胶中处理。用小鼠929成纤维细胞测定细胞生长。丝胶-S水凝胶膜的细胞生长情况优于丝胶-B水凝胶膜。水在丝胶-B和丝胶-S水凝胶膜上的接触角分别为37度和71度。这些值意味着丝胶-B是亲水性或阴离子的，而丝胶-S的阴离子性质低于丝胶-B。膜的ζ-电位值为负值，即阴离子。从接触角数据来看，丝胶-S膜良好的细胞生长是由于方便的接触角而不是阴离子性质造成的。

Biomaterials are usually used in solid state. Sericin obtained by using a usual degumming method is low molecular weight, and its film is very brittle and weak mechanical properties. In this study, we focused to obtain tough membrane and to study the relationship between cell growth and its surface properties.At first, we are prepared the blend of sericin obtained by usual degumming of cocoon with poly(vinyl alcohol) that is low molecular weight and low saponification degree and then the membrane was injected. This membrane is good mechanical properties to use biomaterials because of molecular interaction between amorphous chain of poly(vinyl alcohol) and sericin.Secondly, we prepared two kinds of high molecular weight sericin by using mild extraction condition (Sericin-B), namely boiling only in water, and by using a new sericin rich sericin cocoon (Sericin-S). The hydrogel Sericin-B membrane showed better mechanical properties than the usual degummed sericin membrane, but could not handle as hydrogel membrane. While Sencin-S hydrogel membrane was rubbery. The low molecular weight fracton was also contained in the hydorgel membrane, therefore immersing in pure water at body temperature eluted this fraction. After immersing for 5 days the elution is finished and the membrane was weakened on the mechanical properties although it could handle in the, hydrogel. Cell growth was measured, by using mouse 929-fibroblast cell. Sericin-S hydrogel membrane was better cell growth than Sericin-B hydrogel membrane. The contact angles of the water on the Sericin-B and Sericin-S hydrogel membranes are 37 and 71 degrees, respectively. These values mean that Sericin-B is hydrophilic or anionic, while Sericin-S is lower anionic property than Sericin-B. The values of ζ-potential for these membranes showed minus, namely anionic. From the contact angle data, the good cell growth of Sericin-S membrane caused by the convenient contact angle rather than anionic property.