Microfluidic pulp platform with vascular integration to evaluate biofunctional material.

Biofunctional materials are increasingly used to preserve tooth vitality by promoting dental pulp-mediated hard tissue formation. However, existing evaluation platforms, such as conventional in vitro assays or microfluidic systems, fail to replicate the complex histological and physiological characteristics of dental pulp. This study introduces a 4D biofunctional material-to-pulp (4D BFP) platform that recapitulates pulp physiology, integrating three key features of native pulp tissue: layered histoarchitecture, microcirculatory dynamics, and three-dimensional multicellular organization. This platform further incorporates a temporal dimension by simulating age-dependent vascular transitions, thereby enabling the age-specific modelling of pulp responses, and defining the system as a 4D microfluidic pulp model. Computational fluid dynamics confirmed physiologically relevant flow profiles, while the compartmentalized design supported the spatially organized co-culture of endothelial cell (EC) and human dental pulp stem cell (hDPSC) spheroids. Functional responses to biofunctional material were assessed in both young and mature 4D pulp models. Transcriptomic profiling revealed distinct age- and material-specific signatures related to cellular growth arrest, angiogenesis, and developmental pathways. Collectively, the 4D BFP platform provides a physiological and temporal biomimetic model to study biomaterial-dental pulp interactions, supporting its application as a primary screening tool for candidate biofunctional materials.