How Synthetic ECM Hydrogels Improve Cancer Organoid Models for Drug Discovery

By Abdul Ahad NazakatReviewed by Lauren Hardaker

Synthetic extracellular matrix platforms such as PGmatrix aim to address the reproducibility limitations of tumour-derived scaffolds like Matrigel in oncology drug discovery. By providing chemically defined, tunable hydrogels for organoid and stem-cell culture, these systems may improve the predictive reliability of preclinical cancer models and support the shift toward human-relevant research methodologies.

Image credit: YAKOBCHUK VIACHESLAV/Shutterstock.com

The Reproducibility Gap in Preclinical Oncology

The attrition rates in oncology drug development have remained high for years. Across therapeutic areas, only around 10–15 % of candidates entering clinical trials reach approval, and oncology performs worse than the average. Analyses of large development datasets have placed the overall clinical approval success rate at approximately 12.8 % across nearly 4,000 evaluated drug candidates, underscoring the systemic inefficiency of the current pipeline.¹

A significant portion of this failure stems from preclinical models that do not adequately reflect tumour biology in vivo. Two-dimensional monolayer cell culture, the default tool of early drug discovery, strips away the spatial architecture, mechanical gradients, and cell–matrix signalling that characterize solid tumours. Compounds that perform convincingly in 2D frequently fail to translate, not because they are categorically ineffective, but because the model that identified them was too simplified to surface resistance mechanisms or pharmacological context.²

Animal models provide systemic complexity but introduce confounders: species-specific differences in pharmacokinetics, immune function, and the tumour microenvironment frequently obscure human-relevant responses. The ethical and economic costs of animal testing also face growing institutional scrutiny. Regulatory momentum is shifting accordingly. The FDA Modernization Act 2.0, enacted in 2023, removed the longstanding legislative requirement for animal testing in drug applications, formally opening the door to human-relevant new approach methodologies (NAMs) across the development pathway.³

Matrigel, derived from mouse sarcoma tumour tissue, has been the dominant extracellular matrix (ECM) substitute since the 1980s. Its limitations are well documented: its protein composition is undefined and encompasses thousands of growth factors and cytokines, and batch-to-batch variability can measurably alter organoid morphology and drug sensitivity readouts between experiments, even within the same laboratory. Proteomic analyses have identified thousands of proteins and peptides within Matrigel preparations, reflecting the complexity of the Engelbreth–Holm–Swarm tumour–derived basement membrane extract from which it is produced, a complexity that makes precise experimental control difficult.⁴

Its tumour-derived, xenogenic origin also creates regulatory friction for any application moving toward GMP or therapeutic manufacturing. A 2025 review in Advanced Science characterised this as a field-wide problem, noting that the scientific community has long recognised Matrigel's limitations but that structural and commercial inertia have slowed the transition to defined alternatives. ⁵ For a discipline that requires reproducible, comparable data across sites and studies, these are structural constraints rather than technical inconveniences.

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PGmatrix: What PepGel Is Building and Why It Differs

PepGel was founded by Dr. Xiuzhi Susan Sun, now a Professor at the Wake Forest Institute for Regenerative Medicine and holder of over 17 US patents in biomaterials chemistry, on the premise that the ECM substrate problem is solvable through synthetic peptide engineering. PGmatrix is the company's primary platform: a fully defined, self-assembling peptide hydrogel composed of h9e hybrid peptides that form a fibrous nanofiber network mimicking the native ECM architecture. The material is xeno-free, chemically characterized, and manufactured to batch-consistent specifications, directly addressing the variability problem that undermines Matrigel-based workflows.

Dr. Sun frames PGmatrix's purpose clearly: the platform is intended to provide a "true physiological microenvironment" that preserves "structural and functional cellular integrity", a direct rebuttal to the compromise researchers have historically accepted from animal-derived matrices. The engineering expression of this ambition is tunability. PGmatrix gel stiffness can be adjusted between approximately 500 and 1,000 Pa by varying the gel content from 0.5 % to 1.0 %, enabling researchers to replicate the mechanical properties of specific tissue types or tumour microenvironments. ECM stiffness is not a passive scaffold variable; it actively regulates proliferation, differentiation, and drug resistance via mechanosensing pathways, including YAP/TAZ. A substrate that cannot be controlled for stiffness introduces a confounding variable that, by design, removes defined synthetic alternatives.⁶

The product portfolio reflects a deliberate B2B positioning across multiple segments: PGmatrix 3D Cells (tumour and organoid culture), Stem-X (hiPSC expansion and somatic cell types), Bioink (3D bioprinting), and Injection (in vivo therapeutic delivery). Custom formulations with specific ECM ligand profiles are available for clients requiring tailored biochemical environments, and GMP-grade supply documentation is available for partners approaching clinical translation. The company positions PGmatrix as a complement to existing workflows rather than a wholesale replacement, targeting use cases where defined composition is operationally necessary or scientifically required, rather than competing on price with established commodity suppliers.

Video credit: PepGel/Youtube.com

Organoid Models: Where Defined Matrices Create the Most Value

Tumour organoids have gained considerable traction in oncology research because they preserve the three-dimensional architecture, cellular heterogeneity, and patient-specific molecular profiles that 2D cultures eliminate. Their predictive value, particularly for patient-derived models used in precision oncology and biomarker discovery, depends heavily on the matrix in which they are grown. Independent research has confirmed that established organic scaffolds such as Matrigel introduce biochemical complexity and batch variability that limit experimental reproducibility, and that synthetic hydrogels with tunable mechanics offer a more controlled foundation, though optimization for specific tissue types and cell lines remains necessary on a case-by-case basis.^4,5

The extracellular matrix is not merely a structural scaffold but a dynamic biochemical and biomechanical signalling environment: ECM proteins, glycoproteins, and proteoglycans interact with cell-surface receptors such as integrins to regulate adhesion, migration, proliferation, and differentiation, while matrix stiffness and viscoelasticity influence cell behaviour through mechanotransduction pathways. ⁴

PepGel's published case data report that pancreatic cancer organoids (PANC-1) cultured in PGmatrix achieved a 16-fold increase in proliferation over 10 days at approximately 94 % viability, forming structures 100–150 μm in diameter. Breast cancer organoids (MCF10 series) developed heterogeneous morphologies reported to be consistent with matched xenograft models, and extracellular vesicles secreted by tumour organoids showed approximately 96 % RNA profile similarity to patient-derived plasma bioinformatic data.⁷ These figures are drawn from PepGel's own published reports and have not yet been independently replicated in peer-reviewed multi-site studies, a qualification that matters for clinical adoption and is discussed further below.

That said, a 2024 study in the Journal of Translational Medicine confirmed that conventional matrices such as Matrigel impose batch-to-batch variability and limited tunability, undermining reproducibility in tumour organoid culture, and that synthetic and engineered alternatives offer defined compositions and precise tunability, thereby independently contextualising the limitations PGmatrix is designed to address.⁴

For hiPSC-based programmes, increasingly important for generating patient-derived disease models, PepGel's published data report maintenance of pluripotency markers (OCT4, SOX2, NANOG, UTF1, hTERT) over 37 passages at 15–25× expansion rates. A 2021 peer-reviewed study in Advanced Functional Materials directly validated the underlying mechanism, confirming that PGmatrix supports scalable 3D hiPSC spheroid formation through a controlled degradation-dependent signalling pathway, specifically YAP/TAZ-regulated Hippo signalling, a mechanotransduction pathway known to link matrix stiffness and cell fate decisions in three-dimensional culture systems.⁶ The combination of organoid fidelity, scalability, and mechanobiological consistency positions PGmatrix as a viable tool for both drug screening and biomarker discovery workflows in precision oncology, though real-world adoption data from external pharma or CRO clients is not yet publicly available.

Commercial and Translational Impact: A Realistic Assessment

The commercial argument for defined synthetic matrices in drug discovery is structurally coherent: if preclinical models better predict clinical responses, they improve the quality of go/no-go decisions, reduce late-stage attrition costs, and compress development timelines. In oncology, where a single Phase III failure can cost upward of several hundred million dollars, even marginal improvements in preclinical predictivity can yield substantial pipeline value.¹

But Matrigel's position reflects more than scientific inertia. It represents four decades of validated assay compatibility, an extensive cross-site comparison literature, and deeply integrated supply chains. Switching to a new matrix platform requires internal revalidation of existing protocols, benchmarking against established results, and often a renegotiation of contractual supplier relationships, a cost commitment that is non-trivial for CROs managing standardised service offerings, and for pharma quality assurance teams working under regulatory documentation requirements.

For PepGel, the adoption challenge has three distinct dimensions. First, the most commercially critical performance claims, particularly the organoid RNA fidelity data, currently rest primarily on PepGel's own technical reports. Independent peer-reviewed multi-site replication is the missing element that would most accelerate pharma consideration, and its absence is the honest qualifier that accompanies the platform's otherwise credible technical profile. Second, defined synthetic matrices typically carry a cost premium over Matrigel; at high-throughput screening scale, per-well economics require careful modelling of quantifiable improvements in assay reproducibility before straightforward procurement decisions can be made. Third, regulatory acceptance of new preclinical assay platforms is not automatic; sponsors will need to generate cross-validation datasets against accepted pharmacological endpoints before PGmatrix-based workflows can be incorporated into formal submissions.

The most accessible near-term commercial segments are those where defined composition is already a prerequisite: GMP cell manufacturing, therapeutic organoid programmes, and workflows where Matrigel's xenogenic origin creates direct regulatory friction. These represent smaller but higher-value opportunities compared with the broad preclinical reagents market, and they align well with PepGel's documented capability in GMP supply documentation and custom formulation.

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Industry Trends and PepGel's Positioning

The structural drivers behind PepGel's market positioning are genuine. Regulatory agencies are actively developing frameworks for NAMs and organoid-based submissions. The 2020 Nature Reviews Materials review identified the shift from animal-derived to synthetic scaffolds as a defining direction for the field, noting that synthetic alternatives have, in some cases, demonstrated performance equivalent to or superior to Matrigel when properly validated for the specific application. These synthetic matrices are typically chemically defined, xeno-free, and mechanically tunable, features that directly address the reproducibility and experimental control limitations associated with tumour-derived ECM preparations.⁸

The growing demand for precision oncology tools and patient-derived organoid models used for treatment selection across multiple clinical sites explicitly requires matrices that are standardizable and batch-consistent. Matrigel, structurally, cannot satisfy that requirement.

The global organoid market was valued at approximately USD 545 million in 2024 and is projected to exceed USD 2 billion by 2033, driven substantially by oncology applications.⁹ That trajectory represents both the scale of commercial opportunity and the urgency of resolving the matrix variability problem that constrains broader deployment. PepGel sits at a credible intersection of these converging demands: its scientific foundation is grounded in peer-reviewed research, its GMP documentation capability targets the right regulatory entry points, and its custom formulation service addresses the heterogeneity of ECM requirements across cell types and disease models.

The execution challenge, building independent validation data, scaling commercial infrastructure, and competing with established players, including Corning, Merck, and several emerging synthetic hydrogel companies, is significant but not unusual for a platform company at this stage of development. Whether the field's growing demand for reproducibility, combined with regulatory pressure to reduce animal-derived materials, proves sufficient commercial pull to accelerate that process is the central question PepGel's next phase will answer.

References and Further Reading

1. Yamaguchi, S., Kaneko, M., & Narukawa, M. (2021). Approval success rates of drug candidates based on target, action, modality, application, and their combinations. Clinical and Translational Science, 14(3), 1113–1122. DOI:10.1111/cts.12980, https://ascpt.onlinelibrary.wiley.com/doi/10.1111/cts.12980
2. Foglizzo, V., Cocco, E., & Marchio, S. (2022). Advanced cellular models for preclinical drug testing: From 2D cultures to organ-on-a-chip technology. Cancers, 14(15), Article 3692. DOI:10.3390/cancers14153692, https://www.mdpi.com/2072-6694/14/15/3692
3. FDA Modernization Act 2.0, Pub. L. No. 117-328 (2023). https://www.congress.gov/bill/117th-congress/senate-bill/5002
4. Li, K., He, Y., Jin, X., Jin, K., & Qian, J. (2025). Reproducible extracellular matrices for tumor organoid culture: Challenges and opportunities. Journal of Translational Medicine, 23, Article 497. DOI:10.1186/s12967-025-06349-x, https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-025-06349-x
5. Wolff, L., Hendrix, S., et al. (2025). Rethinking Matrigel: The complex journey to matrix alternatives in organoid culture. Advanced Science, 12(47), Article e08734. DOI:10.1002/advs.202508734, https://onlinelibrary.wiley.com/doi/10.1002/advs.202508734
6. Li, Q., Qi, G. Y., et al. (2021). Universal peptide hydrogel for scalable physiological formation and bioprinting of 3D spheroids from human induced pluripotent stem cells. Advanced Functional Materials, 31(44), Article 2104046. DOI:10.1002/adfm.202104046, https://onlinelibrary.wiley.com/doi/10.1002/adfm.202104046
7. Sun, X. S., & Qi, G. Y. (2025). PGmatrix™ enables physiologically relevant 3D tumor organoids (PepGel PG Report No. 0001). PepGel. https://pepgel.com
8. Aisenbrey, E. A., & Murphy, W. L. (2020). Synthetic alternatives to Matrigel. Nature Reviews Materials, 5(7), 539–551. DOI:10.1038/s41578-020-0199-8, https://www.nature.com/articles/s41578-020-0199-8
9. Straits Research. (2025). Organoids market size, share & trends analysis report, 2024–2033. https://straitsresearch.com/report/organoids-market

Last Updated: Mar 13, 2026