Abstract: To provide an emulsifier for cosmetic use which not only has an improved emulsifying power and feel during use, but wherein the emulsifier itself has a skin cell growth-promoting property. The emulsifier contains an aqueous solution of silk protein composed mainly of amorphous silk fibroin, wherein the aqueous solution of silk protein composed mainly of amorphous silk fibroin is an aqueous solution of silk protein obtained by dissolving unscoured, partially scoured or scoured spun silkworm fibers (cocoon filaments) with a neutral salt and then dialyzing the solution.

Abstract: Peptides are provided having an excellent safety, stability due to relatively low molecular weights thereof, and cell growth promotion, which are different from cell growth factors produced by abnormal cells such as tumor cells. Peptide compositions which are excellent in promoting cell growth containing partial peptides of one or more peptide chains selected from peptide chains forming noncrystalline portions constituting silk protein. The partial peptides have specific amino acid sequences formed of four to forty amino acid residues. This invention has succeeded in providing novel peptides excellent for cell growth by separating and fractionating peptides, having specific amino acid sequences of molecular weights not higher than 10,000, preferably ranging from 4,000 to 400, from the noncrystalline portions of silk protein as well as by synthesizing peptides similar to such peptides.

Abstract: It is an object to provide polypeptide compositions originating from silk protein which have not only excellent cell growth-promoting activity associated with undegraded silk fibroin and sericin, the fibroin H-chain and L-chain, or the a component of sericin, but also excellent touch, extensibility, and the like inherent in fibroin and sericin having a molecular weight not higher than 200,000.

Abstract: Peptides are provided having an excellent safety, stability due to relatively low molecular weights thereof, and cell growth promotion, which are different from cell growth factors produced by abnormal cells such as tumor cells. Peptide compositions which are excellent in promoting cell growth containing partial peptides of one or more peptide chains selected from peptide chains forming noncrystalline portions constituting silk protein. The partial peptides have specific amino acid sequences formed of four to forty amino acid residues. This invention has succeeded in providing novel peptides excellent for cell growth by separating and fractionating peptides, having specific amino acid sequences of molecular weights not higher than 10,000, preferably ranging from 4,000 to 400, from the noncrystalline portions of silk protein as well as by synthesizing peptides similar to such peptides.

Abstract: To provide an emulsifier for cosmetic use which not only has improved emulsifying power and feel during use, but wherein the emulsifier itself has a skin cell growth-promoting property.

Abstract: The object of the present invention is to elucidate a biologically active function of a component constituting undegraded sericin and to provide a novel medical material, cosmetic material, etc. utilizing the functional composition. Disclosed is a cell growth promoter obtainable by elution from a fiber discharged by a domestic silkworm, e.g., cocoon filaments or the like, wherein the cell growth promoter comprises sericin having a molecular weight of about 400,000 as measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) as a main component. This cell growth promoting agent (substance) is extremely useful because growth of cells is promoted when it is used in a wound dressing material, a vascular endothelium forming material and an organ forming material for medical use, in a cell culture base material for biological use, or in a cosmetic material for skin care use.

Abstract: It is an object to provide polypeptide compositions originating from silk protein which have not only excellent cell growth-promoting activity associated with undegraded silk fibroin and sericin, the fibroin H-chain and L-chain, or the a component of sericin, but also excellent touch, extensibility, and the like inherent in fibroin and sericin having a molecular weight not higher than 200,000.

Abstract: The invention provides a cosmetic material containing a crystalline superfine silk powder that has the original structure of silk yarn, properties such as an unique gloss, feeling of touch, flexibility, and elasticity; and various properties such as excellent coating power, spreadability, adhesion, feeling of touch, and formability, which are required of an extender powder or color material of cosmetics. The cosmetic material contains a colored crystalline superfine silk powder obtained by the steps of bringing a silk substance into contact with an alkali aqueous solution at temperatures ranging from 100° C. to 150° C. under a pressure ranging from 1 through 5 atmospheric pressures to weaken the silk substance to not greater than 0.

Abstract: Provided is a process for producing undegraded silk fibroin, which comprises dissolving a cocoon layer or cocoon yarn of fresh, dry or cooked cocoons, raw silk, or silk fabrics, or residual yarns thereof in an aqueous solution of a neutral salt, and then subjecting the resulting solution to fractional precipitation to separate silk fibroin from silk sericin; subjecting the resulting solution to the following step a) or b):

Abstract: The object of the present invention is to elucidate a biologically active function of a component constituting undegraded sericin and to provide a novel medical material, cosmetic material, etc. utilizing the functional composition.

Abstract: The present invention provides a novel material for activating epidermal cell multiplication on which not only effective adhesion and multiplication of human and mammalian epidermal cells is accomplished also intercellular adhesion is promoted to form a plain cellular layer. The present invention provides a material for activating epidermal cell multiplication which contains silk fibroin of &agr;-type or &agr;-helix X-ray diffraction pattern as a principal constituent. The present material fulfills the principal requirements for activating epidermal cells of greatly improved cellular adhesion rate, multiplication, intercellular adhesion and growth of cell layers.

Abstract: The main theme of the invention is to provide a method for manufacturing industrially, by mechanically comminuting silk yarn, crystalline silk fibroin powder below 3 &mgr;m in an average particle diameter, which can be used for various applications. A silk substance such as cocoon filament, silk yarn, or raw silk is brought into an alkali aqueous solution under a pressure of 1 through 5 atmospheric pressure at temperatures from 100° C. through 150° C. to reduce the tensile strength of the silk substance to around 0.02 g/d or less. Thereafter, the resultant silk substance is subjected to dealkalization and drying. Subsequently, the resultant dried silk substance is comminuted into powder below 3 &mgr;m in an average particle diameter. Thus, the crystalline silk fibroin powder below 3 &mgr;m in an average particle diameter is manufactured.

Abstract: There is provided a novel wound dressing material which has biocompatibility and infection controllability as essential properties required for such a material, especially excellent flexibility and water absorption properties, thereby accelerating smooth regeneration of a skin defect without stripping off the regenerating skin while removing the material from the skin. A healing agent is added to the wound dressing material which comprises an amorphous film of a crystallinity below 10% and contains fibroin and sericin as a main component.

Abstract: A wound covering material is provided which can smoothly accelerate repair of a skin defect and which can be readily removed without causing the repaired skin to be removed together therewith. The wound covering material includes a film containing a non-crystalline fibroin.

Abstract: A process is provided for preparing crystalline fine powder of silk fibroin from a silk substance in an industrially advantageous fashion.The process for the preparation of fine powder of the silk fibroin is such that, after the silk substance is brought into an alkaline aqueous solution at a temperature of 95.degree. C. or higher in order to cause a strength of said silk substance to deteriorate, the resulting silk substance is subjected to treatment with alkali and dried, and the dry silk substance is pulverized into finely divided powder.