New Frontiers in Three-Dimensional Culture Platforms to Improve Diabetes Research

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TL;DR

This review comprehensively examines three-dimensional (3D) cell-culture platforms—including scaffold-based systems, organoids, organ-on-chip devices, spheroids, bioreactors, and 3D bioprinting—as superior alternatives to conventional 2D cultures and animal models for diabetes research. The authors argue that 3D models better preserve β-cell morphology, functionality, and intercellular crosstalk, offering improved physiological relevance and drug-predictive power. Despite current limitations in scalability, reproducibility, and vascularization, the integration of biosensors and multi-organ-chip technologies holds significant promise for advancing diabetic drug discovery, disease modeling, and cell-replacement therapies.

Full summary

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**Background:** Diabetes mellitus, affecting over 536 million people globally in 2021 (approximately 6.8% of the world population) and causing an estimated 6.7 million deaths annually, is a chronic metabolic disorder characterized by β-cell dysfunction and hyperglycemia. The authors highlight that conventional 2D monolayer cultures fail to replicate the in vivo microenvironment, leading to altered gene expression, loss of cell polarity, increased apoptosis, and diminished insulin secretion. Animal models, while useful, are limited by species-specific differences in islet architecture, ethical concerns, and poor translational predictability. Three-dimensional culture systems are presented as a promising bridge between in vitro and in vivo models, enabling the replication of cell–cell and cell–extracellular matrix (ECM) interactions critical for β-cell function.

**Methods:** This is a narrative review that synthesizes recent literature on 3D cell-culture technologies applied to diabetes research. The authors categorize and describe scaffold-based systems (e.g., Matrigel, collagen sponges, nanofiber scaffolds, 3D-printed chitosan scaffolds), scaffold-free systems (spheroids, bioreactors, 3D bioprinting), organoid models, and organ-on-chip (OOC) platforms. They discuss fabrication techniques including 3D printing, electrospinning, particle leaching, soft lithography, and microfluidics. Specific examples are provided: Xu et al. used Matrigel to differentiate human dental pulp stem cells into insulin-producing cells; Liu et al. demonstrated that 3D culture enhanced human embryonic stem cell differentiation into pancreatic endocrine cells via FAK-dependent SMAD2/3 pathway inhibition and Cx36 upregulation; Luo et al. developed a microfluidics-based drug-screening model using 3D-cultured INS-1 cells under high glucose; and Wimmer et al. fabricated human blood vessel organoids from stem cells to model diabetic vasculopathy, identifying NOTCH3 and DLL4 as signaling mediators.

**Key Results:** The review reports that 3D-cultured β-cells exhibit improved functionality and survival compared to 2D cultures. For example, murine islets cultivated in rotating-wall vessel bioreactors showed higher stimulation indices than freshly isolated cells. Human islets in stirred-tank reactors with Cytodex-3 microcarriers produced approximately 2.6 times more insulin than 2D cultures. In a pancreas–liver organ-on-chip model developed by Essaouiba and Okitsu, human pancreatic islet micro-tissue and liver spheroids maintained secretory capacity for 15 days under constant pulsatile flow. Spheroids generated via hanging-drop and microwell methods exhibited uniform shape, while self-aggregated spheroids showed improved insulin secretion in response to glucose stimulation compared to native islets. In a diabetic mouse model, transplantation of MIN6 pancreatic cell spheroids generated under simulated microgravity ameliorated hyperglycemia, whereas equivalent 2D-cultured cells did not. Bioprinted alginate-based scaffolds embedding INS1E β-cells maintained viability and improved oxygen/nutrient transport compared to bulk hydrogels. The review also notes that scaffold-free adipose spheroids exhibited greater adiponectin and pro-inflammatory cytokine secretion and better retention of brown adipose tissue markers versus 2D cultures.

**Clinical Implications:** The authors conclude that 3D models address critical gaps in diabetes research by providing physiologically relevant platforms that preserve β-cell phenotype, enhance drug-predictive ability, and reduce reliance on animal models. Organ-on-chip technology enables the study of inter-organ crosstalk (e.g., pancreas–liver axis) in hyperglycemic conditions, which is essential for understanding systemic diabetic complications. Pancreatic organoids and bioprinted constructs hold potential for cell-replacement therapies, though challenges remain in scalability, reproducibility, vascularization, and the incomplete differentiation of stem cells. The integration of biosensors (e.g., 3D electric cell/Matrigel substrate impedance sensing, microneedle glucose biosensors) offers non-invasive, real-time monitoring of cell behavior. The authors emphasize that persistent refinement of 3D technologies—including the incorporation of vessel-specific ECM components, microgravity bioreactors, and multi-organ-chip systems—is necessary before widespread adoption as a standard research platform for diabetes and its complications.