A three-dimensional biological scaffold. The scaffold includes at least three sets of polymer waveguides extending along at least three respective directions. The at least three sets of polymer waveguides interpenetrate each other at a plurality of nodes to form a self-supporting structure. In some embodiments, the polymer waveguides may be bio-degradable. In still some embodiments, the three-dimensional biological scaffold may include one or more coating layers for covering surfaces of the polymer waveguides.