Table 2.

OOC platforms for different tissue and organ types

OOC	Sources	Application	Scaffold	Microfluidic chip fabrication	Key findings	Vessel characteristics	Reference
Brain	hiPSCs	BEM and microfluidic device to improve the structural and functional maturation of human brain organoid	BEM, Matrigel	technique: soft lithography materials: PDMS solution and Sylgard 184 (10:1 ratio) molding: 2.2 mm on patterned master holes: 8-mm diameter, punched bonding: oxygen plasma assembly: stacked PDMS layers with bottom seal sterilization: autoclaved, UV dried flow: rocker system D, 8 mm; H, 0.33 mm; W, 0.9 mm	•BEM has 352 proteins known to show elevated expression in the human brain, while Matrigel has only nine such proteins •BEM-microfluidics organoids were more physiologically relevant and larger than Matrigel organoids (1.84 mm vs. 1.56 mm), with some reaching 4–5 mm •larger populations of RGCs along the VZ in BEM organoid •BEM promoted cortical layer development (day 45) •BEM organoids can be used to model several neurological disorders, providing a balance between cell-type diversity and consistency in organoid growth	N/A	150
	hiPSCs, MCF-7	investigating the impact of exosomes derived from breast cancer cells on brain neurodevelopment	Matrigel	material: PDMS technique: soft lithography structure: two layers; bottom with 1 mm micropillars, top with a 24-well plate ring process: mix PDMS and curing agent (10:1), degas, cure at 80°C (40–60 min), peel off mold	•brain organoids treated with exosomes showed an increased population of OCT4+ cells across multiple days of exposure. The exosomes potentially impaired neurodevelopment of brain organoids	N/A	151
Intestine	HUVECs, mouse ISCs	perfusable mini-gut tubes from stem cells that mimic the intestine’s structure and functions	collagen I, Matrigel	compartments: central hydrogel chamber for organoid culture. Basal side reservoirs for medium diffusion. Inlet/outlet reservoirs for perfusion design features: phase-guiding with semi-walls and pillars. Extra port for hydrogel loading fabrication: designed with CleWin, patterned on silica molded with SU8 photoresist, then PDMS. Plasma-treated PDMS bonded to glass dishes sterilization: cleaned, UV sterilized, and stored sterile	•rapid establishment of a confluent cell sheet in tubular hydrogel scaffolds colonized with mouse ISCs •larger than 3D organoids •cellular diversity closely resembles in vivo conditions and contains cell types rare or absent in traditional organoids •perfusable epithelial tissues were formed	N/A	152
	hiPSCs and HIMECs the epithelial cells were derived from duodenal organoids	–	collagen I, Matrigel	method: Photolithography and demolding of cured PDMS from a master mold PDMS ratio: 15:1 (prepolymer to curing agent) dimensions: cell culture channel (1 × 10 × × 0.15 mm), vacuum chambers (1.68 × 9.09 × × 0.15 mm), wall thickness 100 μm porous membrane: made by casting PDMS over micropatterned silicon, then overlaid and cured with a silanized PDMS slab assembly: bonded with corona plasma treatment; vacuum chambers formed by removing membrane sections bonding: final assembly cured at 80°C for permanent bonding tubing: silicone tubing with connectors for medium and suction flow: monolayer formation achieved with physiological fluid flow (60 μL/h) chip activation: intestine chip subjected to peristalsis-like motions mechanical stimulation: 10% strain at 0.2 Hz, applied via cyclic suction to side chambers	•successful perfusion and mechanical deformation, mimicking peristalsis •mechanical cues improved differentiation and formation of well-polarized epithelium with high density of distinct villus-like structures (∼30/cm2) •cultures that included HIMECs achieved epithelial confluence faster (2 days) compared to those without endothelium (6 days) •HIMECs played a pivotal role in quick epithelial confluence and possibly barrier function •EC-lined microchannels modeled drug absorption, bioavailability, and contributions of circulating immune cells	•perfusable vessels	153
Kidney	H9 hESCs, hiPSCs, hGMECs, HUVECs	culturing kidney organoids under millifluidic conditions	gelatin-fibrin	ink: two-part silicone elastomer, 10:1 ratio, homogenized 3D printing: custom perfusion gaskets, using a bioprinter with a 410-μm nozzle features: gaskets on glass, organoid chamber (15 × 3.6 × × 60 mm), 1 mm ECM organoids: space for 4–20 per chip, in 8 × 3.6 × × 20-mm area curing: 80°C, then autoclaved FSS range: low FSS (1 × 10−7 to 1 × 10−4 dyn/cm2), High FSS (8 × 10−3 to 3.5 × 10−2 dyn/cm2)	•the presence of perfusable lumens supported by mural cells •application of flow significantly enhanced organoid maturation •formation of more refined glomerular and tubular structures •improved nephron segment specification and functionality due to the fluid shear stress (∼1 dyne/cm2) provided by the millifluidic system	•uneven perfusion within the vessels (100-nm beads)	154
Liver	HepaRG, HUVECs, monocyte-derived macrophages, LX-2 (stellate cell line)	–	PET	material: COC - TOPAS from microfluidic ChipShop perfusion: silicone tubing for oxygen chip body dimensions: 75.5 mm (L) × 22.5 mm (W) × 1.5 mm (H) upper channel dimensions: 15.0 mm (L) × 2 mm (W) × 0.45 mm (H) lower channel dimensions: 16.8 mm (L) × 2 mm (W) × 0.40 mm (H) membrane dimensions: 13 mm (L) × 8.5 mm (W) × 0.02 mm (H), with 8-μm pore diameter membrane distances: to upper sealing foil: 0.7 mm to lower sealing foil: 0.8 mm flow rates and shear stress: upper channel: 50 μL/min, shear stress: 0.7 (dyn∗s)/cm2 lower channel: 1 μL/min, shear stress: 0.01 (dyn∗s)/cm2	•hepatic and vascular cell layers were grown on opposite sides of a suspended microporous membrane, which modeled the space of Disse •perfusion only on the vascular side •the model recapitulated oxygen gradient mimicking in vivo conditions and contained all major liver cell types. HepaRG cells dynamically adapted to normoxic and hypoxic conditions	•formation of highly confluent EC layer	155
	HepG2/C3A	liver-on-a-chip platform for long-term culture of 3D human liver spheroids	PMMA, PDMS	multilayer chips: PDMS-membrane-PDMS sandwich structure for spheroid culture; uses PET microporous membrane (3 μm pores, 2 × 106 pores/cm2) for observation upper fluidic layer: designed in AutoCAD, made with soft lithography (2,000 × 200 μm channels) from SU8-2075 on silicon, using PDMS (10:1) lower microwell layer: CNC-milled PMMA master creates 1,080 microwells, converted into a smooth PDMS mold via a secondary PDMS-coating technique, then final PDMS molding (10:1) cured at 80°C for smooth concave microwells	•spheroid-based 3D liver-on-a-chip •microporous membranes modeled the fenestrated ECs in the liver •hepatic spheroids cultured in shallow concave microwells under high mass transfer and low shear stress conditions •minimal spheroid loss under perfusion conditions •higher expression of cytochrome P450, urea, and albumin relative to conventional 3D perfusion models (day 12)	N/A	156
Lung	lung cancer tissue (surgical resection)	culturing 3D lung cancer organoids and conducting drug sensitivity tests within a single system	Matrigel	3D culture methods: includes hanging-drop, biopolymer encapsulation, perfusion bioreactors, and cell sheet layering MPS platform: PDMS-based microfluidic channels for streamlined cell seeding and drug testing design: 29-well device with wells 750 μm deep and 500 μm wide flow: organoids mixed with Matrigel and medium, centrifugally loaded into wells, with a yarn capillary to regulate flow at 2–5 mL/day	•microfluidic platform (29 wells, 750-μm depth, and 500-μm width) cultured LCOs under physiological flow conditions and delivered specific drug concentrations to the LCOs via diffusion •LCOs (200 μm) morphologically resembled typical SCLC lesions •increased expression of stemness markers (CD133, SOX2, and NANOG) under perfusion conditions compared to static Matrigel droplet conditions	N/A	157
	A549, HUVECs, NHLFs	a microphysiological system to model lung cancer by combining 3D tumor spheroids with a self-assembled, perfusable microvasculature	fibrin	fabrication: used soft lithography for PDMS medium reservoir and channel slab dimensions: culture chamber 1,600 × 400 μm, microchannels 400 × 400 μm, reservoir 12 × 12 × × 4 mm process: mixed PDMS with curing agent (10:1), cured at 65°C, added ports, assembled with spin-coated PDMS, and re-cured ECM coating: incubated microchannels with fibronectin solution (25 μg/mL) for 3 h at 37°C channel washing: washed once with EGM-2 cell seeding: introduced 10-μL HUVEC suspension (1 × 107 cells/mL) into channels, allowed attachment for 3 h perfusion setup: connected external reservoirs and syringe pump, set flow rate to 70 μL/h	•3D organotypic model of vascularized human lung adenocarcinoma used for drug (paclitaxel) screening and toxicity assessments •the platform featured a cell culture chamber, an open top, and parallel microchannels for perfusion •the tumor spheroids were mixed vascular cells in fibrin hydrogel supplemented with aprotinin •clinical dose of paclitaxel resulted in endothelial apoptosis, oxidative stress, and vascular inflammation	•3D networks of interconnected endothelial tubes, forming perfusable vessels •the engineered vessels anastomosed with endothelialized side channels •vessel formation was based on self-assembly of ECs and fibroblasts, with vessels exhibiting average diameter of 24 ± 7.05 μm (mean ± SD)	158
Neurovascular	hiPSC-derived ECs, pericytes, and neuroepithelial cells	co-culture of vascular cells and cerebral organoids on a 3D printed microfluidic chip	Matrigel	perfusion: connected to Chemyx pump, perfused at 2 μL/min solution: 1 μm RF-BEADS (1:1,000), fluorescein-40-kDa dextran (500 μg/mL) in PBS visualization: epifluorescence and confocal microscopy for beads and dextran	•cerebral organoids were seeded on day 5 and vascular cells on day 6 •enhanced penetration of ECs in the co-culture condition relative to mono-brain organoids •increased maturation rate of neurons (NeuN+ cells) at days 15 and 30 in the co-culture condition relative to mono-brain organoids •reduction in mature neuron markers in co-cultures compared to mono-brain cultures	•high expressions of endothelial and pericyte markers and formation of intact, lumenized vessels (>1 μm) •invasion of Matrigel (80 μm/day), leading to formation of complex vascular structures	159
Pancreas	hiPSCs	islet-on-a-chip model generated from heterogeneous hiPSC-derived islet organoids	Matrigel	design: multilayer microfluidic chip for islet organoid generation composition: top and bottom PDMS layers, through-hole PDMS membrane, polycarbonate porous membrane function: 3D culture of EBs, media perfusion, interconnected flow between upper and bottom channels flow: continuous culture medium was injected at 100 μL/h advantage: circulatory flow for efficient medium exchange and uniform fluid stress on organoids	•islet organoids comprise heterogeneous islet-specific α and β-like cells, showing enhanced expression of pancreatic β-cell specific genes and proteins •the platform supported the maintenance of organoid morphology (spherical shape with smooth edges) compared to control •islet organoids in the chip were more physiologically relevant, mimicking mature β-cells and had robust response to glucose	N/A	160
Placenta	primary EVTs, ECs, stromal cells, and uNK cells (endometrial biopsies)	implantation-on-a-chip to mimic the 3D organization of the maternal-fetal interface and model the invasion of EVT into the uterus and spiral artery remodeling during implantation	collagen, Matrigel	Fabrication: Soft lithography with PDMS on an SU-8 master for microchannels. design model is a 3D microfluidic device consisting of three parallel lanes: ECM, simulating specialized maternal endometrium; vascular chamber consisting of human uterine ECs, simulating maternal spiral artery; fetal section consisting of human EVTs assembly: sealed with a PDMS layer; top layer includes 7-mm media reservoir holes sterilization: UV irradiated for 20 min surface prep: poly(dopamine) coating for ECM hydrogel attachment, then rinsed and dried	•without trophoblasts, the maternal endothelium showed low apoptosis •the introduction of EVTs led to significant activation of apoptotic pathways in ECs •notable rise in caspase-3-positive ECs and per-cell caspase expression post-EVT invasion, aligning with physiological spiral artery remodeling processes	•EVT invasion disrupts the endothelium, leading to disorganization and reduced VE-cadherin expression, compromising vascular integrity	161
Prostate	LNCaP, PC3	PCa-MPS model to recapitulate epithelial features of PCa and CRPC cells and their PSA and miRNA secretion	agarose, collagen I	chip used: HUMIMIC Chip2 MPS (TissUse, Berlin, Germany) cells cultured: LNCaP and PC3 under dynamic conditions setup: two gels per perfusion circuit in the chip’s culture chambers media: 250 μL per chamber, perfused at 1 Hz for 4 days analysis: supernatant and cell samples collected from conventional, 3D static, and dynamic MPS cultures	•LNCaP cells formed spheroids, influenced by hydrogel density •MPS enhanced cytoskeletal, adhesion protein, and cancer marker expression, indicating an intensified cancer phenotype •MPS reduced PSA secretion and expression in LNCaP cells, suggesting dynamic culture impacts PSA levels •fluidic conditions affected androgen-sensitive and -insensitive cells differently, with implications for cell growth and PSA expression •cytoskeletal response was enhanced in LNCaP under MPS, linking to PSA expression changes	N/A	162
Retina	hiPSC (RPE and RO)	a retina-on-a-chip model that mimics human retinal functions and interactions, aiming to advance drug testing and research into retinal diseases	hyaluronic acid	platform: microfluidic for hiPSC-derived RPE and RO culture with physiological structure configuration: four micro-tissues linked by microchannel, in two-layered biocompatible polymers layers: top for RO/RPE compartments, bottom for nutrient perfusion barrier: porous membrane for nutrient exchange, protects from shear forces procedure: seed RPE cells, culture 24 h inject ROs in hyaluronic hydrogel to separate from RPE culture: initiated for 3 days, stable up to 21 days for analysis or further experiments	•the model integrated over seven types of retinal cells from hiPSCs, providing a comprehensive model •it achieved vasculature-like perfusion and the interaction between photoreceptors and RPE •enabled the formation of outer segment-like structures and in vivo-like functions such as phagocytosis and calcium dynamics •the platform successfully reproduced retinopathic side effects of chloroquine and gentamicin, showcasing its utility in evaluating ocular toxicity •it is a promising avenue for retinal disease study and therapeutic development	N/A	163
	hESCs (H9 and CSC14)	development and validation of a shear stress-free micro-millifluidic bioreactor to standardize and automate the maintenance of retinal organoids	Matrigel	design: SolidWorks-created mold with 200-μm channels and 2-mm chambers in a 6 × 5 array for RtOg culture, compatible with 96-well plates 3D printing: Formlabs form 3B, clear resin; post-processed with isopropanol, air-dried, UV cured fabrication: PDMS cast in 10:1 ratio, degassed, cured at room temperature over the mold assembly: PDMS demolded, ports punched, air plasma-treated, bonded to a glass coverslip	•RtOgs were cultured on a shear stress-free microfluidic bioreactor (31–37 days) •no observable morphological differences between static and bioreactor cultured RtOgs •less oxidative stress (LLS) signatures in bioreactor cultured RtOgs •the micro-millifluidic bioreactor supported long-term culture of RtOgs in a shear stress-free environment	N/A	164
Vascular	NC8 (hiPSCs), HUVECs	a microfluidic platform to cultivate and vascularize 3D cell aggregates	collagen I-Matrigel	device material: COC for durability, mass production, optical clarity, and chemical stability chip design: 10 microchannels, monitored with a 10-channel syringe pump encapsulation method: adapted hydrodynamic trapping for precise organoid placement within serpentine-shaped microchannels organoid positioning: fibrin hydrogel-embedded organoids accurately located at trap sites, maintaining morphology trap dimensions: adjustable based on organoid size; e.g., BVOs (Ø 600 μm, width 300 μm, height 800 μm), spheroids (Ø 300 μm, width 200 μm, height 400 μm)	•HUVEC networks formed functional anastomosis with BVOs •perfused hierarchical vascular network observed under flow •direct connections and functional vascular tree formation suitable for perfusable organoid studies were confirmed	•BVOs developed networks with ECs, pericytes, SMCs, basal membrane, hollow lumens, and tight-junction protein expression •direct connections between BVOs and HUVEC networks formed open microchannels. HUVECs showed 3D organization, CD31 positivity, and functionality confirmed by microbead perfusion •BVOs and HUVEC networks displayed a physiological hierarchy. Upstream/downstream HUVEC vessels were arteriole/venule sized (average 37 μm), internal BVO capillaries averaged 8 μm, and were surrounded by pericytes expressing SM22	165

BEM, brain ECM; CRPC, castration-resistant prostate cancer; BVO, blood vessel organoid; EVT, extravillous trophoblast; HIMECs, human intestinal microvascular ECs; LCO, lung cancer organoid; LNCaP, lymph node metastatic cancer prostate cell line; ISCs, intestinal stem cells; uNK, uterine natural killer; RtOg, retinal organoid.