Abstract: Some embodiments provide method of forming a three-dimensional tissue scaffold that includes extruding a bioink material through a nozzle onto a support while moving the nozzle relative to the support or moving the support relative to the nozzle to form a three-dimensional structure of the bioink material. The bioink material includes a plurality of polymeric fibers, each polymeric fiber having a diameter on a range of 0.1 ?m to 20 ?m, and each polymeric fiber comprising one or more biocompatible polymers, and a carrier. The method also includes cross-linking or heat fusing at least some of plurality of polymeric fibers in the three-dimensional structure of the bioink material.