Silk-based products, formulations, and methods of use
Embodiments of the present disclosure include formulations of silk-based product (SBP) formulations and related methods of preparation and use in a variety of applications in the fields of human therapeutics, veterinary medicine, agriculture, and material science.
1 . A method of preparing processed silk fibroin, comprising
providing silk yarn harvested from a silk producer, the silk yarn comprising silk fibers containing silk fibroin and sericin,
degumming the silk yarn in greater than 0.3 to 0.5 M sodium carbonate at a temperature of about 80 to about 90° C., and for a time of 60 to 480 minutes, to provide degummed silk fibers having a sericin concentration of 0-0.5 wt %,
dissolving the degummed silk fibers using 5M to 13M lithium bromide for 4 hours to overnight at 60° C. to 85° C. to provide dissolved silk fibers, or dissolving the degummed silk fibers using a mixture of calcium chloride, ethanol, and water in a molar ratio of 1:2:8,
diluting the dissolved silk fibers in water to form a solution with a concentration of 5 to 20% w/v silk fibers and optionally filtering the solution through a polypropylene prefilter to remove particulates and provide a clarified silk fiber solution,
performing tangential flow filtration (TFF) on the diluted or clarified silk fiber solution using a regenerated cellulose filter, and
concentrating and recovering processed silk fibroin from the TFF,
wherein the processed silk fibroin has an average molecular weight of 5-50 kDa as determined by high pressure liquid chromatography using a standard comprising Thyroglobulin, IgG, bovine serum albumin (BSA), Myoglobin, and Uracil.
2 . The method of claim 1 , wherein the TFF is performed with a 5 kDa cut-off regenerated cellulose filter.
3 . The method of claim 1 , wherein the silk producer is a species selected from the group consisting of Bombyx mandarina, Bombyx mori, Bombyx sinesis, Anaphe moloneyi, Anaphe panda, Anaphe reticulate, Anaphe ambrizia, Anaphe carteri, Anaphe venata, Anapha infracta, Antheraea assamensis, Antheraea assama, Antheraea mylitta, Antheraea pernyi, Antheraea yamamai, Antheraea polyphemus, Antheraea oculea, Anisota senatoria, Apis mellifera, Araneus diadematus, Araneus cavaticus, Automeris io, Atticus atlas, Copaxa multifenestrata, Coscinocera hercules, Callosamia promethea, Eupackardia calleta, Eurprosthenops australis, Gonometa postica, Gonometa rufobrunnea, Hyalophora cecropia, Hyalophora euryalus, Hyalophora gloveri, Miranda auretia, Nephila madagascarensis, Nephila clavipes, Pachypasa otus, Pachypasa atus, Philosamia ricini, Pinna squamosa, Rothschildia hesperis, Rothschildia lebeau, Samia cynthia , and Samia ricini.
4 . The method of claim 3 , wherein the species is Bombyx mori.