Surface Modification of Electrospun Poly (Methylmethacrylate) (PMMA) Nanofibers for Development of <i>In Vitro</i> Respiratory Epithelium Model

Scaffold design is an important aspect of <i>in vitro</i> model development. In this study, nanoscaffold surface modification, namely UV-radiation and genipin cross-linking to immobilize collagen on the surface of electrospun Poly (methylmethacrylate) (PMMA) nanofibers sheet was investigated. Samples were divided into 4 groups; PMMA nanofibers (PMMA), collagen-coated PMMA nanofibers (PMMACOL), Genipin-crosslinked-collagen coated PMMA nanofibers (PMMAGEN), and UV-irradiated collagen-coated PMMA nanofibers (PMMAUV). 6 hours of UV radiation significantly reduced the hydrophobicity of PMMA nanofibers from (131.88°±1.33°) to (110.04°±0.27°) (p&lt;0.05). The amount of collagen immobilized was significantly higher in PMMAGEN group (239.36±16.63 µg collagen/mg nanofibers) (p&lt;0.05) compared to the other groups. RECs on all scaffold expressed epithelial cell specific markers (CK18 and CK14), mucin producing cell marker (MUC5Ac) and were actively proliferating, based on the positive expression of Ki67. Total number of attached cells was significantly highest in PMMAUV group on day 9 (6.44x10⁴±2.77x10⁴ cells/cm²) and it has the highest proliferation rate from day 4 to 9 (0.005±0.003 h^-1) compared to the other groups. Eventhough PMMAGEN group showed highest collagen adsorption, in terms of cells attachment and proliferation, PMMAUV group showed a better outcome compared to the other groups. Thus, PMMAUV scaffold is more suitable to be used in construction of <i>in vitro</i> respiratory epithelial model.