Automated biofabrication of multicellular tendon in vitro models by embedded coaxial 3D bioprinting

TERMIS EU-Chapter, Palma, İspanya, 21 - 24 Nisan 2026, ss.49, (Özet Bildiri)

Representative multicellular in vitro models allowing the study of tendon

(patho)physiology are highly needed to develop more effective treatments for

tendinopathy, a complex and poorly understood disease for which current

treatments fail in restoring native tissue functionality. Such models would not

only accelerate further understanding on tendon homeostasis and degeneration

mechanisms but also pave the way for the design of in vitro screening platforms

for testing innovative treatment strategies. Here, we combine embedded

bioprinting with coaxial printheads for the 3D writing of tendon-like fascicles

within a cellulose nanocrystals (CNCs) fluid gel support. While CNCs support

bath enables high resolution bioprinting and self-assembles into a tailor-made

bioreactor for long-term in vitro culture[1], coaxial bioprinting allows the

extrusion of single filaments with layer-specific bioinks to recreate tendon

fascicle organization. Human derived tendon cells (hTDCs) and endothelial cells

were used in core and shell bioinks, respectively, aiming to reconstruct the

cellular patterns at the interface of the intrinsic (stroma) and extrinsic (e.g.

vascular system) fascicle compartments. This approach allows the fast

fabrication of multicellular models embedded within its own CNCs support for its

in vitro maturation. hTDCs align and elongate along the fiber core over culture

time, resembling tenocyte morphology, while, in the shell, endothelial cells

reorganize into a vessel-like morphology, surrounding the tendon core

compartment. Gene and protein expression analysis revealed that the long-term

co-culture with vascular compartment suppresses the intrinsic pro-inflammatory

and fibrotic signature of tendon core cell in monoculture. These results further

indicate that hTDCs switch from a distressed state to a more quiescent and

homeostatic state when co-cultured with endothelial cells, favoring the

maintenance of a healthy tenogenic phenotype. Altogether, this strategy

enables the rapid and reproducible 3D biomanufacturing of humanized tendon

in vitro models that may be used for testing innovative tendinopathy therapies in

the future.

Acknowledgements: EU Horizon 2020 and EU Horizon Europe for ERC

grants No. 772817 and 101171765; FCT/MCTES for

DOI:10.54499/2022.05526.PTDC, PD/BD/129403/2017, and 2023.01198.BD.

[1] R. F. Monteiro, et al. ACS Applied Materials & Interfaces 2023 15 (44),

50598-50611.