From Fabrication to Function: Scalable Spray-Assisted Layer-by-Layer Films for Drug Delivery in Glaucoma

Glaucoma drainage device (GDD) surgery is frequently limited by postoperative fibroblast proliferation, leading to device failure and the need for revision procedures. In this work, we developed a spray-assisted layer-by-layer (LbL) drug delivery system for GDD surfaces intended to enable localized release of antiproliferative agents, as a proof-of-concept approach toward more standardized patient care. Multilayer thin films composed of poly(β-amino ester) (PBAE) and a 5-fluorouracil (5-FU) and β-cyclodextrin (β-CD) complex (5-FU:β-CD) were fabricated, without (type A films) and with (type B films) graphene oxide (GO) barrier layers. Film growth was monitored by ultraviolet-visible spectroscopy (UV-Vis) and vacuum ultraviolet spectroscopy (VUV), confirming consistent, sequential deposition; type A films exhibited lower variability than GO-containing type B films. Drug release studies revealed a rapid burst release within the first 5 min, followed by a plateau, regardless of GO incorporation, indicating that sustained drug release was not achieved under the current film architecture. Cell cycle analysis confirmed that β-CD complexation preserved the biological activity of 5-FU, which induced an S-phase arrest in a dose-dependent manner. Although further optimization of film architecture and composition is required to improve release control and achieve sustained delivery, this study demonstrates the feasibility of spray-assisted LbL coatings as a localized drug delivery strategy for GDD surfaces. Overall, these findings support the proof-of-concept nature of this approach and identify key parameters that must be optimized before translational applicability can be established.