Stable silk protein fragment compositions
A composition is disclosed that includes pure silk fibroin-based protein fragments that are substantially devoid of sericin, wherein the composition has an average weight average molecular weight ranging from about 17 kDa to about 38 kDa, wherein the composition has a polydispersity of between about 1.5 and about 3.0, wherein the composition is substantially homogeneous, wherein the composition between 0 ppm to about 500 ppm of inorganic residuals, and wherein the composition includes between 0 ppm to about 500 ppm of organic residuals.
1. A composition comprising lyophilized silk fibroin protein fragments that are substantially devoid of sericin, the silk fibroin protein fragments having an average weight average molecular weight selected from about 17 kDa to about 38 kDa, about 35 kDa to about 40 kDa, about 40 kDa to about 45 kDa, about 45 kDa to about 50 kDa, about 50 kDa to about 55 kDa, or about 39 kDa to about 80 kDa, and a polydispersity of about 1.5 to about 3.0, wherein, prior to being lyophilized, the silk fibroin protein fragments:
form a substantially homogeneous solution comprising between 0 ppm to about 500 ppm of inorganic residuals and between 0 ppm to about 500 ppm of organic residuals, and do not spontaneously or gradually gelate and do not visibly change in color or turbidity when in a solution for at least 10 days.
2. The composition of claim 1 , wherein the inorganic residuals include lithium bromide.
3. The composition of claim 1 , wherein the organic residuals include sodium carbonate.
4. A reconstituted silk fibroin protein fragments solution, comprising dissolved lyophilized silk fibroin protein fragments of claim 1 and a solvent, wherein the reconstituted solution is substantially homogeneous and does not spontaneously or gradually gelate and does not visibly change in color or turbidity for at least 10 days.
5. The reconstituted silk fibroin protein fragments solution of claim 4 , wherein the solvent comprises water.
6. The reconstituted silk fibroin protein fragments solution of claim 4 , wherein the concentration of silk fibroin protein fragments in the solution is from about 0.1 wt % to about 30.0 wt %.
7. The reconstituted silk fibroin protein fragments solution of claim 4 , further comprising 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, metal ion, metal oxide, polyanhydrides, cells, fatty acids, fragrance, minerals, plant extracts, preservatives, and essential oils.
8. The reconstituted silk fibroin protein fragments solution of claim 4 , further comprising one or more therapeutic agents.
9. The reconstituted silk fibroin protein fragments solution of claim 8 , wherein the one or more therapeutic agents comprises vitamin C or a derivative thereof.
10. The reconstituted silk fibroin protein fragments solution of claim 4 , further comprising an alpha hydroxy acid selected from the group consisting of glycolic acid, lactic acid, tartaric acid and citric acid.
11. The reconstituted silk fibroin protein fragments solution of claim 8 , wherein the one or more therapeutic agents comprises hyaluronic acid or a salt thereof at a concentration of about 0.5 wt % to about 10.0 wt %.