The challenge the researchers set out to solve is one of geometry and biology combined. Most laboratory studies of Kawasaki disease rely on flat, two-dimensional sheets of endothelial cells, the thin lining that coats the inside of blood vessels. Such cultures are easy to grow and easy to analyze, but they bear little resemblance to the real thing. A coronary artery is a hollow, curved, multilayered tube in which endothelial cells interface with blood on one side and smooth muscle cells wrap the exterior, providing structural support. Animal models, particularly mice, have been used for decades, but the differences between mouse and human vascular and immune biology often limit how well findings translate to the clinic. The team, led by Xuting Zhang and colleagues at Wenzhou Medical University and collaborating institutions, hypothesized that recreating the true three-dimensional, bilayered architecture of a coronary artery would yield a far more faithful model of the disease.

Their manufacturing method of choice was microfluidic coaxial bioprinting, an elegant technique that exploits the same principle as a pipe within a pipe. The researchers assembled a device from glass capillaries and injection needles, aligning an inner capillary concentrically inside an outer one. Two fluids were pumped through this coaxial nozzle: an outer bioink containing 10 percent gelatin methacryloyl, or GelMA, blended with polyethylene glycol diacrylate, or PEGDA, and an inner sacrificial stream of 10 percent polyvinyl alcohol. When the co-flowing streams emerged from the capillary tip, ultraviolet light at 405 nanometers triggered photopolymerization of the outer hydrogel, locking in a continuous tube. The uncrosslinked PVA core was then simply washed away, leaving behind a hollow hydrogel microfiber with an open lumen running its entire length.

The precision achievable with this setup is remarkable. By adjusting the relative flow rates of the inner and outer fluids, the team could dial in the dimensions of the fibers at will. Holding the inner flow at 15 milliliters per hour and raising the outer flow from 15 to 35 milliliters per hour shifted the ratio of inner to outer diameter from about 65.5 percent down to 58.4 percent, while the outer diameter swelled from roughly 712 to 911 micrometers. Reversing the adjustment, by accelerating the inner stream while holding the outer one constant, enlarged both the overall caliber and the relative lumen. Throughput was equally impressive: a single milliliter of bioink yielded between roughly 4 and 6.5 meters of continuous hollow fiber, depending on the diameter chosen, underscoring the scalability of the approach.

Mechanical tuning came from the PEGDA content. Three formulations containing 2.5, 5, and 7.5 percent PEGDA in 10 percent GelMA produced hydrogels with Young’s moduli of approximately 73, 153, and 221 kilopascals respectively, and rheological testing confirmed the same trend in storage modulus. Swelling behavior plateaued within 24 hours, and the matrices retained more than 95 percent of their mass after a day in culture medium, yet dissolved completely within 24 hours when exposed to the enzyme collagenase, showing that degradation is enzymatically controllable rather than a product of passive hydrolysis. Importantly, the softest formulation, 10 percent GelMA with 2.5 percent PEGDA, proved best for early cell attachment, because PEGDA, while excellent for structural strength, tends to resist cell adhesion. That formulation was selected for all subsequent vascular constructs.

With the scaffold optimized, the researchers populated it with human cells in a deliberate sequence. First, human umbilical vein endothelial cells, or HUVECs, at a density of 10 million cells per milliliter were injected into the lumen and allowed 72 hours to engraft, forming a continuous endothelial monolayer with uniform circumferential alignment. Then human coronary artery smooth muscle cells, at 100 million cells per milliliter, were applied to the outer surface, where they colonized the exterior and formed a distinct smooth muscle layer. Confocal microscopy of the cytoskeleton and immunostaining confirmed the architecture: the endothelial marker CD31 lined the luminal surface, while alpha-smooth muscle actin was confined to the outer layer, faithfully reproducing the bilayered organization of a native coronary artery.

Crucially, the model was more than a structural mimic. When the team perfused fluorescent dextran molecules of 4 and 70 kilodaltons through the lumen, the endothelialized constructs allowed far less leakage into the surrounding hydrogel than acellular controls, demonstrating that the engineered endothelium functioned as a selective barrier to both small solutes and large plasma proteins, just as a real vessel does. As a positive control, exposure to the inflammatory molecule TNF-alpha for six hours triggered a cascade of endothelial activation: elevated lactate dehydrogenase release signaling membrane injury, increased oxidative stress, upregulation of the adhesion molecules ICAM-1, VCAM-1, and E-selectin, a surge of inflammatory cytokines and chemokines including IL-1beta, IL-6, IL-8, CX3CL1, CCL5, and MCP-1, and clear activation of the NF-kappaB signaling pathway, traced by the phosphorylation of I-kappaB-alpha and the p65 subunit.

The decisive test came when the constructs were bathed in serum drawn from children during the acute phase of Kawasaki disease, before intravenous immunoglobulin therapy, mixed at a 10 percent volume ratio into the culture medium, with serum from age-matched healthy children as the control. Within six hours, the patient serum drove the engineered arteries into a state that mirrored the disease: heightened endothelial injury and oxidative stress, intensified expression of all three adhesion molecules, a broad transcriptional inflammatory response, and robust NF-kappaB activation. The serum also triggered pyroptosis, a fiery form of programmed cell death, evidenced by upregulation of the inflammasome sensor NLRP3, the executioner protein gasdermin D, and caspase-1. This finding aligns with growing evidence that pyroptotic endothelial death contributes to the coronary artery lesions that make Kawasaki disease dangerous, and it suggests that NF-kappaB signaling and the NLRP3 inflammasome operate in a reinforcing loop rather than as separate, sequential events.

The platform then proved its worth as a drug-testing instrument. Pretreating the constructs with atorvastatin, the widely used statin, at a non-toxic concentration of 10 micromolar significantly blunted the inflammatory response to Kawasaki serum, suppressing adhesion molecule and cytokine expression and dampening NF-kappaB phosphorylation, consistent with the statin’s known anti-inflammatory, lipid-independent pleiotropic effects and with early clinical trials of atorvastatin in Kawasaki patients with coronary aneurysms. The selective NLRP3 inhibitor MCC950, also tested at 10 micromolar, likewise reduced ICAM-1 expression and inflammatory mediator transcripts, and it specifically shut down the pyroptotic machinery, lowering NLRP3, gasdermin D, caspase-1, and IL-1beta. Because intravenous immunoglobulin resistance remains a major clinical problem, the ability to distinguish these two mechanistically distinct protective strategies within a single human tissue model is exactly the kind of preclinical capability the field has lacked.

The authors are candid about the model’s current limits. The constructs were cultured under static conditions, without the fluid flow and shear stress that shape endothelial behavior in living arteries, and future versions will incorporate dynamic perfusion. The endothelial layer consists of HUVECs rather than coronary-specific endothelial cells, a pragmatic choice driven by the robust proliferation needed to form an intact barrier in a bioprinted scaffold. Even so, the achievement stands out. In a single platform, the team has combined tunable biofabrication, native-like multilayered architecture, functional barrier properties, patient-derived disease induction, and mechanistically resolved drug evaluation. For a disease that strikes young children, has no known cause, and can leave permanent cardiac damage, this bioprinted coronary artery equivalent offers a powerful new window into pathogenesis and a versatile testing ground for the therapies of tomorrow.

Subject of Research: Biomimetic 3D bioprinted coronary artery models for Kawasaki disease modeling and drug screening

Article Title: Engineering biomimetic coronary artery equivalents for Kawasaki disease modeling and drug screening

Article References: Zhang, X., Shao, C., Wang, Y., Liu, A., Rong, X., Jia, C., Yu, W., Zhang, H., Wu, R., Zhang, J., Zhang, L., Ye, F., & Chu, M. (2026). Engineering biomimetic coronary artery equivalents for Kawasaki disease modeling and drug screening. Materials Today Bio, 41, Article 103701. https://doi.org/10.1016/j.mtbio.2026.103701

Image Credits: AI Generated

DOI: 10.1016/j.mtbio.2026.103701

Keywords: Kawasaki disease, coronary artery, bioprinting, microfluidics, GelMA, endothelial dysfunction, NF-kB, pyroptosis, NLRP3, atorvastatin, MCC950, drug screening