Synthesis of Novel Methacrylate Monomers and Their Application in MSLA-Printed Microneedles

Abstract

This study aims to develop biocompatible resins to fabricate microneedles (MNs) using mask stereolithography (MSLA) as a 3D printing technology. Six monomers were utilized, five of which were synthesized, and all were incorporated into photopolymerizable resin formulations. Specific characteristics can be incorporated into the needles depending on the type of monomer and polymer formed. Microneedle sets were formed by polymers in both the bottom plate and the needle shafts, which could be made from the same material or different polymers, imparting additional properties to the sets. This resulted in 19 distinct microneedle sets, including solid, flexible, dissolvable, and swellable devices. Physicochemical characterization confirmed the structural integrity of the materials. Mechanical testing assessed the mechanical integrity and performance of the materials and the MNs. Thermal stability analysis indicated that printed polymers were thermally stable at high temperatures. Printed samples in MNs were highly biocompatible, and more than 80% cell viability was observed. MNs reached 1 mm in mean height, which allows for stratum corneum penetration, as verified by OCT (Optical Coherence Tomography) testing on Parafilm “M”. In short, the study demonstrated the feasibility of biocompatible (meth)acrylate resins for fabricating different MNs through MSLA.