3D Printing of Polytetrafluoroethylene Hollow Needles for Medical Applications

The delivery of drugs or vaccines using hollow needles involves a "poke and flow" approach, which involves the movement of the drug or vaccine through the bore of a hollow needle. In this paper, hollow needle arrays were created out of the fluoropolymer polytetrafluoroethylene using a digital light processing (DLP)-based 3D printing process. Confocal laser scanning microscopy revealed that the hollow needles in the three-by-one hollow needle array contained sharp tips, uniform heights, and hollow bores. X-ray photoelectron spectroscopy and Raman spectroscopy revealed that the elemental composition and carbon bonding of the 3D printed polytetrafluoroethylene matched that of bulk polytetrafluoroethylene, respectively. The reduced elastic modulus of the needle material, 1.94 +/- 0.22 GPa, is appropriate for skin penetration and is similar to that previously described for bulk polytetrafluoroethylene. The needle array was used to deliver methyl blue, a model drug, to surgically discarded human abdomen skin. These results suggest that DLP-based 3D printing of polytetrafluoroethylene may be an appropriate approach for producing needle arrays and other technologically relevant devices.