Abstract: A staple cartridge is disclosed. The staple cartridge can include a cartridge body, a plurality of staples, and an implantable layer. The implantable layer can include a piece of lyophilized foam and a plurality of fibers at least partially embedded in the piece of lyophilized foam. The implantable layer can further include a plurality of pores defined in piece of lyophilized foam, and a plurality of pockets, wherein a pocket at least partially surrounds a fiber. A method of forming an implantable layer for use with a surgical staple is also disclosed. The method can comprise obtaining a mold comprising a cavity, placing a plurality of fibers in the cavity of the mold, dispensing a solution into the cavity around the fibers, and lyophilizing the solution in the cavity.