Barrier Barrier-on-Chip

Barrier Barrier-on-Chip is a versatile microfluidic platform engineered for constructing and studying tissue barrier models including the blood-brain barrier (BBB), intestinal epithelium, renal proximal tubule, and pulmonary alveolar-capillary barrier. The chip features an apical and basolateral chamber separated by a porous membrane, enabling establishment of polarized epithelial or endothelial monolayers with functional barrier properties.

The flexible design supports multiple membrane pore sizes (0.4-8.0 um) to accommodate different barrier types and experimental requirements. The optically transparent construction enables high-resolution live-cell imaging, TEER measurement, and fluorescent tracer permeability assays. Dedicated inlet/outlet ports enable independent perfusion of apical and basolateral compartments, supporting studies of directional transport, efflux pump activity, and immune cell transmigration.

Manufactured from biocompatible materials with low drug absorption properties, the Barrier chip ensures accurate drug concentration maintenance during transport studies. The chip is sterile and ready-to-use, with a shelf life of 12 months. Each box contains 4 chips compatible with standard multi-channel pump systems and TEER measurement devices.

The Barrier Barrier-on-Chip enables multiple applications in barrier biology and drug development:

1. **Blood-Brain Barrier (BBB) Modeling**: Establish iPSC-derived BBB models with brain microvascular endothelial cells co-cultured with astrocytes and pericytes for CNS drug permeability assessment and neuroinflammation studies.

2. **Intestinal Absorption Studies**: Model human intestinal epithelium with Caco-2 or primary intestinal cells to evaluate oral drug bioavailability, nutrient absorption, and barrier integrity under inflammatory conditions.

3. **Renal Proximal Tubule Models**: Reconstruct kidney proximal tubule epithelium for nephrotoxicity assessment, drug secretion/reabsorption studies, and renal disease modeling.

4. **Pulmonary Barrier Studies**: Model alveolar-capillary barrier for inhalation toxicology studies, drug delivery across the air-blood barrier, and acute lung injury modeling.

5. **Immune Cell Transmigration**: Study neutrophil, T-cell, and monocyte transmigration across activated endothelium under inflammatory conditions to model immune surveillance and neuroinflammation.

6. **Efflux Transporter Studies**: Assess P-gp, BCRP, and MRP2-mediated drug efflux through bidirectional permeability measurements, critical for DMPK and drug-drug interaction studies.

7. **Skin Barrier Models**: Model epidermal barrier with keratinocyte layers for dermal drug permeability and skin irritation studies.

**Barrier Chip Setup Protocol:**

**Step 1: Membrane Selection and Coating**
- Select appropriate membrane pore size: 0.4-1.0 um for tight barriers (BBB), 1.0-3.0 um for absorption studies, 3.0-8.0 um for immune cell migration
- Coat membrane with appropriate ECM (collagen IV, fibronectin, or Matrigel) for your cell type
- Apply coating solution to both apical and basolateral sides
- Incubate at 37 C for 2-4 hours, then rinse with PBS

**Step 2: Cell Seeding**
- For BBB: Seed endothelial cells (hCMEC/D3 or iPSC-BMEC) on the apical side at 2x10^5 cells/cm2
- For intestinal barrier: Seed Caco-2 cells on the apical side at 5x10^4 cells/cm2
- For co-culture models: Seed supporting cells (astrocytes, pericytes) on the basolateral side first
- Incubate statically for 24-48 hours before initiating perfusion

**Step 3: Barrier Maturation**
- Maintain static culture for 3-7 days (cell type dependent)
- Change medium every 2 days on both sides
- Monitor TEER daily to track barrier formation
- Typical TEER values at maturity: BBB >200 ohm.cm2, intestinal >400 ohm.cm2

**Step 4: Experimental Assays**
- For permeability: Add fluorescent tracer (sodium fluorescein, FITC-dextran) to the donor compartment
- For drug transport: Add test compound and collect receiver compartment samples at time points
- For immune migration: Add immune cells to the basolateral compartment and monitor transmigration
- For efflux studies: Perform bidirectional (A-to-B and B-to-A) permeability measurements