Disclosed are injection molded devices including microneedles on a substrate base. The microneedles may include a plurality of nano-sized structures fabricated thereon. The molds used to form the microneedles are assembled from a plurality of mold segments, each defining portions of the microneedles. Upon assembly of the multiple mold segments, microneedle negative cavities are formed. The molds may be used in an injection molding process to form microneedle arrays. Devices may be utilized for interacting with a component of the dermal connective tissue.
