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with viscous bioinks . SLA leverages photopolymerization to achieve high resolution
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(<20 μm) , critical for replicating intricate microchannel architectures that mimic in

vivo vascular networks. Despite its precision, SLA is constrained by material brittleness
and limited compatibility with cell-laden hydrogels unless modified for

biocompatibility. 2PP stands out for its sub-200 nm feature resolution, enabled by

nonlinear optical absorption. This technique is ideal for creating nanoscale topographies

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that influence cell migration or drug diffusion in cancer models . However, 2PP’s slow
throughput and high operational costs restrict its use to specialized applications. FDM

remains the most cost-effective (<$0.50/cm³) option for rapid prototyping, using

thermoplastics like PLA or ABS. While FDM is accessible and scalable, its resolution

(~100–300 μm) and surface roughness often necessitate post-processing for

microfluidic applications.

The selection of an optimal 3D printing modality for tumor modeling demands a

systematic evaluation of three critical, interdependent parameters: spatial resolution,

which governs the precision of microchannel geometries and cellular-scale

features; biomaterial compatibility, determining suitability for cell encapsulation, ECM
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mimicry, and long-term culture viability ; and economic feasibility, ensuring a balance
between fabrication precision, functional performance, and budget constraints—

particularly crucial for large-scale studies. A comprehensive comparative analysis of

these factors (summarized in Table 3) is vital to align fabrication strategies with specific

research objectives, such as replicating hypoxia gradients, vascular networks, or

metastatic microenvironments. Emerging innovations, including hybrid printing

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techniques (e.g., integrating SLA with i3DP) and advanced bioresins , hold promises
for bridging current limitations in resolution, biocompatibility, and cost efficiency,

thereby expanding the potential of 3D-printed tumor models.

Compared to traditional manufacturing, 3D printing provides exceptional design

freedom and enables personalized, decentralized production. It produces complex

geometries with high precision; its additive nature minimizes material waste, reducing

costs and environmental impact 37,55 . However, there are still numerous challenges

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