Speaker
Description
Light-based biofabrication techniques like filamented light (FLight) offer robust architectural alignment but are often limited in compositional complexity[1]. Conversely, acoustic assembly enables non-contact, label-free patterning of cellular spheroids or bioactive particulates, yet lacks architectural guidance at the microstructural level[2]. To achieve tissue functionality, such as muscle, nerve, and cartilage, the convergence of biofabrication technologies is essential for providing biochemical, mechanical, and architectural cues[3,4].
Here, we demonstrate a modular biofabrication platform that combines bulk acoustic wave (BAW)-based patterning with filamented hydrogels to create hierarchically organised, multi-material constructs. Using 1 mm-thick custom-made cassettes, ceramic particulates are acoustically patterned into defined geometries within various cell-laden hydrogel precursor solutions, including Gelatin, Gelatin methacryloyl (GelMA) and silk mixed with Ruthenium (Ru)/sodium persulfate (SPS). These cassettes were able to serve as an independent unit for spatially resolved biomaterial loading and cellular composition. Critically, distinct cassettes were selectively designed to include either aligned fibrous architectures (via FLight exposure) or bulk, non-aligned hydrogels, introducing deliberate regions of varied topography, biochemical and mechanical properties.
Following vertical assembly, constructs were photo-crosslinked with either laser wavelengths (401 nm or 526 nm) tailored for individual cassette or cross-cassette integration, respectively. This approach enabled precise modulation of filament orientation both within and across several layers, facilitating complex multi-material, multi-cellular environments within a single centimetre-scale construct.
Cell-laden constructs with human dermal fibroblasts and murine myoblasts (C2C12) showed excellent viability (>90%) over 7 days. Moreover, cells demonstrated robust alignment and elongation in FLight-aligned regions, while distinct morphologies and proliferation profiles were observed in non-aligned (bulk) hydrogel and ceramic particle domains, demonstrating effective tailoring of cell-matrix interactions.
This multi-modality strategy enables rapid fabrication of distinct modular engineered tissue units with customizable biochemical, mechanical, and architectural features into a single construct. The versatility to combine diverse biomaterials and structural cues within stackable units offers new opportunities for regenerating muscle-tendon interfaces, creating zonally organised cartilage, and developing physiologically relevant disease models.
[1] H. Liu, P. Chansoria, P. Delrot, E. Angelidakis, R. Rizzo, D. Rütsche, L. A. Applegate, D. Loterie, M. Zenobi-Wong, Advanced Materials 2022, 34.
[2] R. Tognato, R. Parolini, S. Jahangir, J. Ma, S. Florczak, R. G. Richards, R. Levato, M. Alini, T. Serra, Mater Today Bio 2023, 22, 100775.
[3] Y. Li, G. Huang, X. Zhang, L. Wang, Y. Du, T. J. Lu, F. Xu, Engineering cell alignment in vitro, Vol. 32, Elsevier Inc., 2014, pp. 347–365.
[4] J. Chi, M. Wang, J. Chen, L. Hu, Z. Chen, L. J. Backman, W. Zhang, Topographic Orientation of Scaffolds for Tissue Regeneration: Recent Advances in Biomaterial Design and Applications, Vol. 7, MDPI, 2022.
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