Fabrication, Simulation, and Mechanical Characterization of Curcumin-Loaded PVA/PVP Microneedle Arrays Using Custom 3D-Printed Molds

This study developed curcumin-loaded dissolvable PVA/PVP microneedle arrays using a workflow that combined polymer formulation, CAD design, finite element analysis, stereolithography-assisted mold fabrication, mechanical testing, swelling analysis, insertion testing, and release profiling. PVA and PVP were blended at a 3:1 ratio with sorbitol and varying curcumin contents, then evaluated as microneedle matrices for localized wound-healing drug delivery. Increasing curcumin loading reduced mechanical strength and stiffness: ultimate tensile strength decreased from 4.81 MPa in the drug-free formulation to 2.48 MPa in the 10 mg curcumin formulation, while Young’s modulus and yield strength also declined and strain at maximum force increased. Swelling analysis showed that higher curcumin loadings produced rapid water uptake followed by structural collapse, while lower to moderate curcumin formulations maintained more controlled swelling behaviour. Finite element analysis compared conical, pyramidal, and bullet-shaped geometries across multiple array configurations and showed that conical designs provided the best balance of deformation, stress distribution, and factor of safety. Four conical models were selected for fabrication and experimental validation. Insertion and penetration testing on porcine skin showed high puncture efficiency, with selected models achieving approximately 92.56% to 96.69% penetration efficiency and insertion depths of 960 to 1220 µm. SEM confirmed successful mold replication and conical needle formation, although drug-loaded microneedles showed surface irregularities and internal voids that could contribute to mechanical weakening. Overall, the study identified moderate curcumin loading and optimized conical array spacing as a reproducible strategy for fabricating mechanically robust dissolvable microneedle patches for transdermal wound-healing applications.