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International Journal of Bioprinting Bioprinted vascular tumor model

comprising tumor cells, stromal cells, vascular networks, coaxial bioprinting, inkjet printing, and fused deposition
and the extracellular matrix (ECM), where intricate modeling (FDM). Notably, coaxial bioprinting enabled
interactions govern tumor progression, drug penetration, the fabrication of dual-layered vascular constructs
and therapeutic response. Thus, the development of featuring endothelial and smooth muscle layers, a design
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in vitro tumor models that integrate multiscale vascular strategy aimed at mimicking native vascular architecture.
networks and recapitulate TME dynamics is essential to Concurrently, inkjet printing achieved high-precision
overcoming current research bottlenecks. tumor spheroid generation (±10 μm dimensional

Traditional 2D cell models, though simple and suitable consistency), effectively addressing the heterogeneity
for high-throughput screening, fail to replicate the 3D limitations inherent in conventional spheroid formation
cell–cell interactions, metabolic gradients, and drug techniques. The FDM-fabricated perfusion culture chip
diffusion barriers of solid tumors. Animal models, further advanced the system’s functionality by facilitating
5,6
while capable of mimicking in vivo tumor environments, dynamic tumor–vascular co-culture and enabling real-time
face limitations due to high costs, species-specific microenvironment monitoring. Preliminary mechanistic
discrepancies, and ethical concerns. In contrast, 3D investigations leveraging this integrated platform revealed
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tumor models better approximate the TME by simulating insights into paclitaxel-mediated suppression of tumor
spatial cell arrangements, heterogeneity, and ECM metastasis. Collectively, this model successfully simulated
physicochemical properties. At present, tumor spheroid- tumor-associated vascular radial growth, early metastatic
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based models are the primary focus of 3D tumor models. events, and drug responses, providing a robust platform for
These models, resembling human tumors in morphology, investigating tumor–vascular interactions and evaluating
high cell density, and chemical environment, effectively anti-angiogenic therapies.
establish physiological metabolic gradients. Furthermore,
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these models are often integrated with tumor cells and 2. Materials and methods
fibroblasts. The latter, by secreting angiogenic factors 2.1. Materials
such as vascular endothelial growth factor (VEGF), plays Human fetal lung fibroblast 1 (HFL1; CCL-153), human
an essential role in tumor growth, invasion, metastasis, umbilical vein endothelial cells (HUVECs; CRL-1730),
and angiogenesis. 10–12 The fabrication of tumor spheroids human aortic vascular smooth muscle cells (HA-VSMCs;
primarily relies on traditional techniques, including ultra- CRL-1999), and human hepatocellular carcinoma G2
low adhesion methods, hanging drop techniques, 14–16 (HepG2; HB-8065) were purchased from the American
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and droplet overlay methods. 17–19 While these approaches Type Culture Collection (ATCC, United States of America
are simple to operate, they exhibit significant limitations; [USA]). Dulbecco’s Modified Eagle Medium (DMEM),
for instance, they lack precise control over spheroid 0.25% Trypsin-EDTA, and phosphate-buffered saline
diameter. 20–22 Furthermore, most current studies are (PBS) were obtained from Wuhan Servicebio Technology
restricted to monoculture systems of tumor cells, failing to Co., Ltd. (China). Fetal bovine serum (FBS) was sourced
systematically integrate key functional units of the TME, from Lonsa Sience SRL (Uruguay). Penicillin-streptomycin
such as perfusable vascular networks and immune cell was purchased from Gibco (USA). Anhydrous calcium
infiltration. 23–25 chloride, propidium iodide (PI), DiO (green cell membrane
Blood vessels, as pivotal functional units of the TME, not fluorescent probe), DiI (orange cell membrane fluorescent
only deliver oxygen and nutrients but also regulate immune probe), 4% paraformaldehyde, Triton X-100, gelatin (bloom
cell infiltration and drug delivery. Native vasculature number: 240~270), and bovine serum albumin (BSA) were
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features a complex tri-layered structure (intima, media, obtained from Sangon Biotech Co., Ltd. (China). Lithium
adventitia), where endothelial and smooth muscle cells phenyl-2,4,6-trimethylbenzoylphosphinate (LAP),
synergistically maintain vascular tone, barrier function, fibronectin, methacrylic anhydride, and Calcein-AM were
and paracrine signaling. 27–30 Existing in vitro vascular obtained from Shanghai Aladdin Biochemical Technology
models, however, primarily rely on endothelial-lined Co., Ltd. (China). Pluronic F-127, Phalloidin-FITC,
hollow channels, which neither mimic layered vascular alginate, and fibrinogen were purchased from Sigma-
structures nor support long-term perfusion. 31–35 While 3D Aldrich Corporation (USA). Thrombin was obtained from
bioprinting offers new avenues for constructing spatially Yeasen Biotech Co., Ltd. (China). Total RNA extraction
controlled vascularized models, integrating multiscale commercial kit, reverse transcription kit, and 2× Universal
vascular networks (from macrovessels to capillaries) with Blue SYBR Green qPCR Master Mix were obtained from
tumor spheroids remains technically challenging. In this Mei5 Biotechnology (China). Gelatin methacryloyl
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study, we present an innovative multiscale vascularized (GelMA) and type I rat tail collagen were synthesized in-
tumor model developed through the integration of house. Anti-CD31 antibody (152 μg/mL) was obtained

Volume 11 Issue 4 (2025) 379 doi: 10.36922/IJB025180180