Speaker
Description
INTRODUCTIO
The synovial lining is responsible to produce synovial fluid into the joint capsule. The synovial fluid acts as a lubricating and protecting layer for the articular cartilage to ensure pain-free frictionless movement of the articular joint. The synovial lining is prone to inflammation from injury, overuse or inflammatory arthritis (1), but modelling these events in vitro, while accurately mimicking the synovial cell composition is challenging. Advances in organ-on-chip (OoC) devices could help to replicate physiological conditions and provide high-throughput in vitro modelling platforms to study novel drugs and their effect. Tissue function correlates intimately with its unique microarchitectural structures. Hence, the faithful incorporation of such microarchitectures in OoC is anticipated to increase their physiological relevance.
In this project, we present a novel strategy to increase complexity and cell disposition in open-top OoC models through LIFT bioprinting directly in synovial lining OoC devices. This approach enables the generation of pre-vascular networks within OoC models that are then closed and perfused at physiological flow rates.
METHODS
Human synovial fibroblasts were isolated from total knee arthroplasty surgeries; human Mesenchymal Stromal Cells (MSC) were isolated from bone marrow. GFP-Human Umbilical Vein Endothelial Cells (HUVEC) were purchased from Lonza. Open-top OoC were fabricated using an SLA 3D printer and Polydimethylsiloxane (PDMS). Synovial fibroblasts were encapsulated in 1mg/mL Collagen type 1 solution containing 2U/mL Thrombin and HUVEC-GFP were LIFT printed suspended in 15mg/mL Fibrinogen. After LIFT printing, OoC were sealed using double-sided tape and cultured in static conditions or under low and high flow rates. Lastly, the production of lubricin and vascular sprouting of the HUVEC was assessed via fluorescent microscopy and ELISA.
RESULTS
Open-top OoC have been successfully fabricated, and synovial fibroblasts were embedded on the cell culture chamber with high viability. Three cell-seeding conditions were studied, synoviocytes only, synoviocytes mixed with HUVEC, and synoviocytes with LIFT printed HUVEC on top of the cell culture chamber. All chips were subjected to both high and low flow rate perfusion. On the LIFT printed condition, the printed vascular pattern was maintained over 7 days of culture and showed interactions between synoviocytes and HUVEC, forming a lumenized structure that attracts cytokines and immature THP1 monocytes upon TGF b and LPS stimulation.
CONCLUSION
LIFT allows rapid and reproducible micropatterning of cells with high viability, as well as multi-cellular multi-material printing. Here, we show the micropatterning of small pre-vascular features in open-top OoC devices to mimic the microarchitecture of native tissue and recreate the onset of inflammation in the synovial lining with THP1 naive monocyte recruitment.
REFERENCES
1.- Clare L Thompson et al 2023 Biomed. Mater. 18 065013
53381508655
