3D Models and Tissue Engineering for Colorectal Cancer Drug Screening

3D models and tissue engineering for colorectal cancer drug screening offer a more representative way to study tumor microenvironments, allowing researchers to evaluate treatment responses and investigate why certain drugs may not work. Two-dimensional (2D) monolayer cultures are unable to fully reproduce the interactions between cells and the extracellular matrix (ECM), tissue stiffness, cellular heterogeneity, and the distribution of nutrients found in living tumors. Conventional flat cultures may overestimate the effectiveness of certain treatments, contributing to differences between preclinical findings and clinical outcomes.

Advanced tissue-engineered scaffolds, patient-derived organoids (PDOs), and microfluidic tumor-on-a-chip systems can reproduce selected features of tumor architecture and biology. These platforms provide opportunities to investigate chemotherapy, targeted therapies, and, when appropriate immune components are incorporated, immunotherapies in preclinical settings. However, their ability to reliably predict individual patient responses remains under investigation. (Fong et al., 2016; Al-Kabani et al., 2025)

3D Models vs 2D Cultures in CRC

3D models and tissue engineering approaches for colorectal cancer drug screening offer advantages over traditional monolayer systems by providing experimental platforms that reproduce selected aspects of complex in vivo tumor biology. Conventional preclinical screening relies heavily on flat substrates, while advanced 3D systems can recreate features of extracellular matrix architecture and tissue microenvironments that influence therapeutic responses. (Al-Kabani et al., 2025)

Structural and Biological Limitations of 2D Cell Cultures

Traditional 2D cell cultures require colorectal cancer cells to adhere to flat plastic surfaces, which can change their morphology, gene expression, and interactions with neighboring cells. Monolayer cells generally experience more uniform exposure to oxygen, nutrients, and therapeutic agents than cells within solid tumors.

Without native three-dimensional tissue architecture and extracellular matrix interactions, 2D models cannot fully reproduce cell-to-cell and cell-to-matrix signaling. These limitations may lead to overestimation of drug sensitivity for certain treatments. However, 2D cultures remain useful for investigating cellular mechanisms and conducting initial drug screening. (Al-Kabani et al., 2025)

Physiological Advantages of 3D Models and Tissue Engineering

By replacing two-dimensional substrates with tissue-engineered constructs, researchers can reproduce selected physical and biological features that influence cancer cell behavior. These models provide opportunities to investigate several important components of the tumor microenvironment. (Fong et al., 2016)

Nutrient and Oxygen Gradients

Nutrient and oxygen gradients can create distinct cellular regions within sufficiently large 3D tumor spheroids. The outer regions may contain actively proliferating cells, while deeper regions can become relatively quiescent, hypoxic, or necrotic. This spatial arrangement resembles features of poorly vascularized tumor tissues and can influence how therapeutic agents affect different cell populations and how cells adapt their metabolism. The extent of these gradients depends on the size and characteristics of the experimental model. (Al-Kabani et al., 2025)

Extracellular Matrix Interactions

Decellularized tissue scaffolds, hydrogels, and engineered matrices provide mechanical and biochemical signals that influence cancer cell behavior. Properties such as matrix stiffness and composition can affect cell adhesion, migration, signaling, and therapeutic sensitivity. These platforms allow researchers to investigate how interactions between cancer cells and the extracellular matrix contribute to tumor progression and treatment resistance. However, their effects depend on the matrix composition and experimental conditions. (Fong et al., 2016)

Cellular Heterogeneity

Multicellular 3D models can incorporate colorectal cancer cells alongside cancer-associated fibroblasts, endothelial cells, and immune cells to investigate interactions within the tumor microenvironment. Including different cell populations allows researchers to study tumor–stroma signaling and selected aspects of the immune microenvironment. Models containing functional immune components may also support investigations of immunotherapy mechanisms, although their ability to predict clinical immunotherapy responses requires further validation. (Fong et al., 2016; Al-Kabani et al., 2025)

Drug Penetration Barriers

In three-dimensional models, dense cellular structures and extracellular matrix networks can function as physical barriers that restrict the diffusion of therapeutic agents. These features allow researchers to investigate aspects of the limited drug penetration observed in solid tumors and how drug distribution influences treatment sensitivity. However, the extent of these barriers depends on the cellular organization and matrix composition of each model. (Fong et al., 2016)

Core Biofabrication Strategies

Biofabrication combines biological elements with engineered matrix materials to create experimental platforms used in cancer research and drug development. Modern biofabrication methods employ different engineering approaches to reproduce selected structural and cellular features of tumors. (Fong et al., 2016)

Patient-Derived Organoids

Patient-derived organoids (PDOs) are created from tumor tissue samples obtained during surgical resection or biopsy. Under appropriate culture conditions, these cells can form three-dimensional structures that preserve important histologic and molecular characteristics of the original tumor, including selected genetic alterations.

In a prospective study published in 2015, van de Wetering and colleagues established a living organoid biobank using samples from colorectal cancer patients. As described in the review by Al-Kabani and colleagues, this work demonstrated the potential of colorectal cancer organoids for drug screening and investigating associations between molecular characteristics and treatment sensitivity.

PDOs also have limitations. Conventional organoid cultures generally lack the complete stromal, vascular, and immune components of the original tumor, which can restrict their ability to reproduce treatment responses influenced by the surrounding microenvironment. (Al-Kabani et al., 2025)

3D Bioprinting

3D bioprinting techniques, including extrusion-based and droplet-based approaches, allow researchers to position cells and biomaterials within defined spatial configurations. These methods can be used to construct multicellular experimental models containing colorectal cancer cells and selected components of the surrounding microenvironment.

In 2023, Wang and colleagues developed a 3D bioprinted colorectal cancer model containing SW480 colorectal cancer cells, M2-type tumor-associated macrophages, and endothelial cells. The researchers compared conventional 2D cultures with single-cell and multicellular 3D bioprinted models to examine differences in biological characteristics and chemotherapy sensitivity.

The multicellular model demonstrated greater resistance to 5-fluorouracil (5-FU), oxaliplatin, and irinotecan than the single-cell 3D bioprinted model. These findings showed that incorporating additional cell types can influence drug sensitivity in an experimental colorectal cancer system. However, the model was constructed using established cell lines rather than patient-derived colorectal cancer cells, and its ability to predict individual patient responses was not established. (Wang et al., 2023)

Tissue Decellularization

Tissue decellularization involves removing cellular components from biological tissues while aiming to preserve the underlying extracellular matrix structure and composition.

The resulting decellularized extracellular matrix (dECM) scaffolds can retain aspects of the original tissue architecture, collagen organization, and biochemical signals. These scaffolds provide an environment for introducing tumor cells and investigating their interactions with tissue-derived matrix components. Fong and colleagues reviewed the use of decellularized matrices in experimental cancer models, including their potential to reproduce aspects of the surrounding tissue environment.

However, the removal of cellular components does not guarantee complete preservation of the original extracellular matrix. The structural and biochemical properties of the resulting scaffolds depend on the tissue source and decellularization method. (Fong et al., 2016)

Microfluidic Tumor-on-a-Chip Systems

Microfluidic tumor-on-a-chip systems use devices containing small channels that allow controlled fluid movement to reproduce selected features of the tumor microenvironment.

These systems can mimic aspects of tissue perfusion, fluid-associated mechanical forces, and drug delivery. Some platforms incorporate multiple cell types, extracellular matrix materials, and endothelial cell-lined channels to investigate interactions between cancer cells and their surrounding environment.

By controlling the supply of nutrients and therapeutic compounds, researchers can evaluate treatment responses under dynamic culture conditions. However, individual tumor-on-a-chip systems do not fully reproduce whole-body drug metabolism or clearance without additional organ-specific components or integrated modeling approaches. (Al-Kabani et al., 2025)

Predictive Mechanisms of Therapeutic Resistance

Colorectal cancer can develop therapeutic resistance through genetic alterations, changes in cellular signaling, drug penetration barriers, and interactions with surrounding stromal cells that support tumor survival. Tissue-engineered three-dimensional models can reproduce selected aspects of these resistance mechanisms under laboratory conditions. However, not all models retain patient-specific resistance characteristics, and their predictive value depends on the cellular composition and treatment being evaluated. (Al-Kabani et al., 2025)

Chemotherapy Resistance

Three-dimensional bioprinted models can demonstrate different sensitivities to standard chemotherapy agents, including 5-fluorouracil (5-FU), oxaliplatin, and irinotecan, compared with traditional 2D cell cultures. Patient-derived organoids can also be used to evaluate drug sensitivity, although their predictive performance depends on the experimental setting and treatment being investigated. (Wang et al., 2023; Vlachogiannis et al., 2018) These differences may reflect the effects of cellular organization, extracellular matrix interactions, and additional cell types within experimental models. (Wang et al., 2023)

In 2018, Vlachogiannis and colleagues developed patient-derived organoids from heavily pretreated patients with metastatic gastrointestinal cancers, including colorectal cancer, gastroesophageal cancer, and cholangiocarcinoma, who were participating in early-phase clinical trials. The researchers demonstrated that these organoids retained important molecular and phenotypic characteristics of the original tumors. They also compared laboratory drug sensitivity with treatment responses observed in patients.

Across 21 evaluable comparisons involving patients with metastatic gastrointestinal cancers, organoid testing demonstrated 100% sensitivity and 93% specificity for predicting responses to targeted therapies or chemotherapy. Although these findings were promising, they were obtained from a selected cohort and do not establish reliable predictive accuracy across all patients or treatment regimens. (Vlachogiannis et al., 2018)

Additional experimental evidence came from Wang and colleagues, whose multicellular 3D bioprinted colorectal cancer model showed greater resistance to 5-FU, oxaliplatin, and irinotecan than the corresponding single-cell 3D model. These findings support the use of 3D platforms for investigating chemotherapy resistance, although the study did not establish clinical predictive accuracy. (Wang et al., 2023)

Targeted Therapy Evaluation

Three-dimensional colorectal cancer models containing alterations in KRAS, NRAS, or BRAF can be used to investigate changes in MAPK pathway signaling and mechanisms of resistance to targeted therapies.

Activating RAS mutations are associated with resistance to anti-EGFR monoclonal antibodies such as cetuximab and panitumumab. BRAF alterations can also influence responses to EGFR-targeted treatment, although their implications depend on the specific mutation and therapeutic regimen.

In their 2018 study, Vlachogiannis and colleagues evaluated responses to cetuximab in colorectal cancer organoids. Two organoid models established before anti-EGFR treatment showed resistance to cetuximab, consistent with the clinical resistance observed in the corresponding patients. These models carried either a KRAS G12D or BRAF V600E alteration.

These findings illustrate how PDOs can be used to investigate relationships between molecular characteristics and drug responses, without establishing universal predictive accuracy. (Vlachogiannis et al., 2018; Al-Kabani et al., 2025)

Stroma-Mediated Protection

Cancer-associated fibroblasts can influence tumor survival and therapeutic resistance through extracellular matrix remodeling and the release of signaling molecules, including transforming growth factor-beta (TGF-β) and hepatocyte growth factor (HGF).

These factors participate in interactions between cancer cells and their surrounding stromal environment. Fibroblast-derived signals may also influence therapeutic sensitivity through the activation of cellular signaling pathways.

Incorporating fibroblasts into 3D experimental models allows researchers to investigate these interactions and their potential contribution to treatment resistance. However, the effects depend on the cancer type, cellular model, and therapeutic agent being studied. (Fong et al., 2016)

Conclusion

Three-dimensional models and tissue engineering provide complementary approaches for investigating colorectal cancer biology, therapeutic responses, and mechanisms of drug resistance. Patient-derived organoids can preserve important molecular features of individual tumors, while bioprinted constructs, engineered scaffolds, and microfluidic systems allow researchers to examine selected interactions within the tumor microenvironment.

Although these platforms have demonstrated value in preclinical research, no single model fully reproduces the biological complexity of colorectal cancer. Further standardization and prospective clinical validation are needed before 3D drug-screening approaches can be routinely used to guide treatment decisions for individual patients. (Fong et al., 2016; Al-Kabani et al., 2025; Vlachogiannis et al., 2018)

Find more videos on OncoDaily YouTube TV.

References

1. Fong ELS, Harrington DA, Farach-Carson MC, Yu H. Heralding a new paradigm in 3D tumor modeling. Biomaterials. 2016;108:197–213. DOI | PubMed
2. Al-Kabani A, Huda B, Haddad J, Yousuf M, Bhurka F, Ajaz F, et al. Exploring experimental models of colorectal cancer: A critical appraisal from 2D cell systems to organoids, humanized mouse avatars, organ-on-chip, CRISPR engineering, and AI-driven platforms—challenges and opportunities for translational precision oncology. Cancers.2025;17(13):2163. DOI | PubMed
3. Vlachogiannis G, Hedayat S, Vatsiou A, Jamin Y, Fernández-Mateos J, Khan K, et al. Patient-derived organoids model treatment response of metastatic gastrointestinal cancers. Science. 2018;359(6378):920–926. DOI | PubMed
4. Wang P, Sun L, Li C, Jin B, Yang H, Wu B, Mao Y. Study on drug screening multicellular model for colorectal cancer constructed by three-dimensional bioprinting technology. International Journal of Bioprinting.2023;9(3):694. DOI | PubMed

Written by Tatev Barseghyan, MD