Abstract: The present invention relates to silk fibroin bioinks specifically formulated for use in 3D bioprinting and the production of ex-vivo models capable of supporting hematopoiesis and the production of platelets and blood cells.

Abstract: The present invention provides, among other things, methods for producing platelets including the steps of providing a silk membrane about 2 ?m and 100 ?m thick, inclusive, contacting the silk membrane with a porogen to form a porous silk membrane comprising at least one silk wall defining a lumen, associating the porous silk membrane with stromal derived factor-1? and at least one functionalizing agent, forming a three dimensional silk matrix comprising interconnected pores wherein the pores have a diameter of between about 5 and 500 ?m, inclusive, wherein the silk matrix is formed around at least a portion of the porous silk membrane, introducing a plurality of megakaryocytes to the silk matrix such that the megakaryocytes are located at least partially within the porous silk matrix, and stimulating the plurality of megakaryocytes to produce platelets. Also provided are various new compositions and methods of making those compositions.

Abstract: The present invention provides, among other things, methods for producing platelets including the steps of providing a silk membrane about 2 ?m and 100 ?m thick, inclusive, contacting the silk membrane with a porogen to form a porous silk membrane comprising at least one silk wall defining a lumen, associating the porous silk membrane with stromal derived factor-1? and at least one functionalizing agent, forming a three dimensional silk matrix comprising interconnected pores wherein the pores have a diameter of between about 5 and 500 ?m, inclusive, wherein the silk matrix is formed around at least a portion of the porous silk membrane, introducing a plurality of megakaryocytes to the silk matrix such that the megakaryocytes are located at least partially within the porous silk matrix, and stimulating the plurality of megakaryocytes to produce platelets. Also provided are various new compositions and methods of making those compositions.