Stable Silk Protein Fragment Compositions

1 - 20 . (canceled)

21 . A method of preparing a silk composition comprising the steps of:

(a) degumming a silk source by adding the silk source to a boiling (100° C.) aqueous solution of sodium carbonate for a treatment time of between about 30 minutes to about 60 minutes;

(b) removing sericin from the solution to produce a silk fibroin extract comprising non-detectable levels of sericin;

(c) draining the solution from the silk fibroin extract;

(d) dissolving the silk fibroin extract in a solution of lithium bromide having a starting temperature upon placement of the silk fibroin extract in the lithium bromide solution that ranges from about 80° C. to about 140° C.;

(e) maintaining the solution of silk fibroin-lithium bromide in a dry oven having a temperature in the range between about 60° C. to about 100° C. for a period of at least 1 hour;

(f) removing the lithium bromide from the silk fibroin extract; and

(g) producing an aqueous solution of silk protein fragments; wherein the aqueous solution of silk protein fragments does not spontaneously or gradually gelate and does not visibly change in color or turbidity when in a solution for at least 10 days.

22 . The product of the process of claim 21 , wherein the aqueous solution comprises pure silk fibroin-based protein fragments having an average weight average molecular weight ranging from about 39 kDa to about 80 kDa and a polydispersity of between about 1.5 and about 3.0.

23 . The product of claim 22 wherein the inorganic residuals include lithium bromide and wherein the organic residuals include sodium carbonate.

24 . The product of claim 22 wherein the lithium bromide residuals are measurable using a high-performance liquid chromatography lithium bromide assay, and the sodium carbonate residuals are measurable using a high-performance liquid chromatography sodium carbonate assay.

25 . The product of claim 22 in a sealed container.

26 . The method of claim 21 further comprising the step of adding one or more molecules selected from the group consisting of therapeutic agents, growth factors, antioxidants, proteins, vitamins, carbohydrates, polymers, nucleic acids, salts, acids, bases, biomolecules, glycosamino glycans, polysaccharides, extracellular matrix molecules, metals, metal ion, metal oxide, synthetic molecules, polyanhydrides, cells, fatty acids, fragrance, minerals, plants, plant extracts, preservatives and essential oils.

27 . The method of claim 21 further comprising the step of adding vitamin C or a derivative thereof.

28 . The method of claim 21 further comprising the step of adding an alpha hydroxy acid selected from the group consisting of glycolic acid, lactic acid, tartaric acid and citric acid.

29 . The method of claim 21 further comprising the step of adding hyaluronic acid or its salt form at a concentration of about 0.5% to about 10.0%.

30 . The method of claim 21 further comprising at least one of zinc oxide or titanium dioxide.

31 . The product of claim 22 wherein the pure silk fibroin-based protein fragments are hypoallergenic.

32 . The product of claim 22 having less than 10 colony forming units per gram.

33 . The product of claim 21 wherein the average weight average molecular weight range and the polydispersity are measurable using a high-performance liquid chromatography assay.

34 . The method of claim 21 , wherein the aqueous solution of silk protein fragments does not spontaneously or gradually gelate and does not visibly change in color or turbidity when in a solution for at least 30 days.