Systems, devices, and methods are provided for assembling polymer-forming molecular components such that highly-structured arrays of polymer strands, such as collagen fibrils, are formed without the need for cells. A polymer nanoloom is designed to control the self-assembly of monomers into fibrils and related tissue constructs including ligament, tendon, cartilage, and bone. A nanoloom system comprises a polymer printhead, a temperature controller, and a movable substrate for polymer printing. A polymer printhead contains one or more nanoreactors that can control the assembly of collagen fibrils or other polymers on a nanoscale. Methods are provided for temperature-driven, enzyme-driven, and cholesteric assembly of collagen or other polymers into two- or three-dimensional tissue constructs.