Photonics technologies in constituting human 3D tissue models

Recent advancements in molecular biology have facilitated the routine engineering of artificial human tissues. Typically, DLP bioprinters are utilized for creating 3D matrices that incorporate either specific cell types or transient spheroids/organoids. However, engineering complex neuronal or innervated tissue models necessitates the use of high-precision femtosecond (fs) laser-printing technology, offering nano and micrometer resolutions. Despite the prevalent use of hi-PSC-derived cell lines for human model engineering, the complexity and cost remain significant challenges. In response, we explored the efficacy of a calcium imaging for the non-destructive functional assessment of 3D neuronal networks derived from neural progenitors, focusing on their differentiation into functionally active, post-mitotic neurons. Furthermore, we developed a custom-built dual-mode fluorescence spectroscopy (FS) and Optical Coherence Tomography (OCT) system for evaluating the metabolism and morphology of full-thickness skin equivalents (FSE) cultivated on laser-printed 3D scaffolds. Our findings demonstrate that the integration of calcium and dual-mode FS-OCT systems enables the comprehensive monitoring of functionality, morphology, and metabolism in developing human brain-like and FSE models. Consequently, 3D laser-printed scaffolds, when combined with these innovative monitoring technologies, offer a feasible and efficient approach to engineering human tissue models.