3D Multiphoton Nanolithography with Bioresorbable Amino Acid-Based Resins

We demonstrate that the newly designed amino acid phosphorodiamidate resins (APdA), containing vinyl reactive groups for polymerization, can be utilized to fabricate sub-100 nm features through 3D multiphoton lithography. We have quantitatively analyzed the feature size, Young's modulus, and functionalization of the nanostructures using atomic force and single-molecule fluorescence microscopy. Our results indicate that the polymer backbone, composed of either valine or alanine, imparts hydrophobic properties to the monomer, restricting the swelling of the polymeric nanostructure to 8% in aqueous environments. Despite minimal swelling, experiments revealed an up to 10-fold change of Young's modulus for dry versus wet conditions. To enhance the versatility of the APdA-based structures, we incorporated biotin functionalization and used it for the immobilization of extracellular vesicles. Hence, these findings highlight the potential of APdA-based nanolithography photoresists for biomedicine and nanotechnology applications.