Levofloxacin-Loaded Microneedles Produced Using 3D-Printed Molds for Klebsiella Pneumoniae Biofilm Control

Abstract

Additive manufacturing advancements contribute considerably to several fields and its use in the medical field is gaining attention due to its easily customizable option (patient-specific), low cost, and fast turnout time in developing drug delivery and diagnostic tools. Herein, the fabrication of a microneedle (MN) platform is reported using a stereolithography 3D printer, varying the 3D printing angle and aspect ratio (2:1, 3:1, and 4:1). The optimal printing angle is 30°, resulting in needle tip and base diameters of ≈50 and ≈330 µm and heights of ≈550/850/1180 µm. Polyvinyl alcohol (PVA) MNs produced with varying levofloxacin concentrations show variability of ≈4% in tip and 3% base diameters and 15% in height compared to the 3D-printed MNs. Geometry B is used to produce levofloxacin-loaded PVA MNs and tested against Klebsiella pneumoniae colony biofilms. Levofloxacin is released gradually, as assessed by spectrofluorimetry. The minimum inhibitory concentration of levofloxacin against the K. pneumoniae clinical isolate is 4 µg mL−1 but this concentration is insufficient to cause any effect on K. pneumoniae biofilms. Only concentrations ≥32 µg mL−1 are statistically different compared to the unloaded MNs. 3D printing is an attractive solution to produce molds for fabricating biopolymeric MNs for topical drug delivery.