Dynamic <i>in vitro</i> platform for mechanical profiling of human pulmonary aciniform organoids via intraluminal access

Reproducing the biomechanical complexity of human alveoli in vitro remains a major challenge in respiratory research. Here, we present an integrative platform combining Pulmonary Aciniform Organoids (PAcinOs) with a custom device, Dynamic Exposure and Infusion Response Observer (DENIRO), enabling structural visualization, intraluminal access and dynamic real-time biomechanical assessment. Acinar microanatomy of PAcinOs was generated by fusion of multiple spheroids of human induced pluripotent stem cell-derived lung progenitors, and cultured within DENIRO, enabling optical coherence tomography–based volumetry and microfluidic pressure control. The porous interluminal connectivity supports dynamic measurement of changes in collective volume and organoid compliance. Bleomycin treatment induced fibrotic phenotypes, including reduced volume and compliance, mimicking disease-associated mechanical stiffening. Treatment with the antifibrotic drug nintedanib yielded partial mechanical recovery, reflecting the clinically measured treatment response. This human-relevant system models dynamic three-dimensional respiratory biomechanics in vitro, capable of quantitative mechanical and pharmacological testing. Our findings demonstrate that PAcinOs in DENIRO offer a flexible platform for complex lung disease modeling, drug screening and investigation of mechanobiological tissue behavior in vitro.