Smart 4D‐Printed Optically Responsive Hybrid Biomaterials with Enhanced Cell‐Adhesion Properties for Dynamic In Vitro Lung Modeling

Abstract Vat polymerization (VP) is a high‐resolution 3D printing technique ideal for fabricating intricate, micron‐scale geometries suitable for tissue modeling. However, the development of biocompatible soft tissue‐mimicking resins remains a significant challenge. Here, this work presents a dynamic, optically responsive 4D biomaterial designed for lung tissue modelling, to replicate mechanical stimuli associated with breathing. This thermoresponsive hybrid resin printable by Liquid Crystal Display‐based VP, is composed of N‐vinyl caprolactam (VCL), polyethylene glycol diacrylate (PEGDA), and functionalized plasmonic gold nanorods (AuNRs) with an 800 nm plasmon band. The combination of AuNRs and VCL enables near‐infrared light‐triggered cyclic swelling and shrinking of the polymer, with a contraction‐expansion rate of 6%. This novel resin allows the fabrication of high‐fidelity biomimetic scaffolds incorporating 400 µm honeycomb‐shaped cavities that resemble alveolar geometry. Lung epithelial cells successfully form monolayers on the scaffold surface and show enhanced adhesion to surfaces containing positively charged AuNRs by thiolated polyarginine functionalization. Additionally, the optically triggered mechanical stimulation activates mechanotransduction pathways in these cells. This approach offers a promising strategy to engineer dynamic, biomimetic scaffolds for in vitro lung modeling.