Perfusion Perfusion-on-Chip

Perfusion Perfusion-on-Chip is an advanced microfluidic platform designed for high-throughput drug screening using dynamic perfusion culture. The chip features a unique ring-shaped main perfusion channel connected to 4-6 independent branch culture units, each capable of maintaining distinct cell cultures under continuous medium flow. The design enables generation of concentration gradients and supports dose-response experiments in a single integrated device.

The ring perfusion architecture ensures uniform nutrient delivery and waste removal across all culture chambers while maintaining independent experimental conditions. When integrated with an upstream gradient generator, the chip can create linear or logarithmic concentration gradients across the branch units, enabling simultaneous testing of multiple drug doses or drug combinations.

The chip material is optically transparent for high-quality imaging and is compatible with standard fluorescence assays, live-cell imaging, and endpoint analyses. The inlet/outlet ports are designed for easy connection to syringe pumps, peristaltic pumps, and automated liquid handling systems. Each box contains 4 sterile chips with a 12-month shelf life.

The Perfusion Perfusion-on-Chip supports multiple applications in drug discovery and cell biology:

1. **Dose-Response Drug Screening**: Test 4-6 drug concentrations simultaneously in a single chip under identical perfusion conditions, generating complete dose-response curves from one experimental run.

2. **Drug Combination Studies**: Create overlapping concentration gradients of two drugs to identify synergistic, additive, or antagonistic interactions across a full combination matrix.

3. **Pharmacokinetic Profiling**: Continuous perfusion enables time-resolved sampling of drug concentrations and metabolites, supporting PK/PD modeling in a miniaturized format.

4. **Chronic Drug Exposure**: Long-term perfusion culture (up to 14 days) enables assessment of chronic drug effects, adaptive resistance, and delayed toxicity that short-term static cultures cannot capture.

5. **Dynamic Culture of Sensitive Cell Types**: Continuous nutrient delivery supports culture of fastidious cell types and primary cells that may not thrive in static conditions.

6. **Metabolic Studies**: Perfusate collection enables continuous monitoring of cell-secreted metabolites, providing real-time metabolic profiling during drug treatment.

7. **Organoid Drug Screening**: Compatible with 3D organoid cultures embedded in ECM, enabling high-throughput drug sensitivity testing of patient-derived organoid models under perfusion conditions.

**Perfusion Chip Setup Protocol:**

**Step 1: System Assembly**
- Connect chip inlet to medium reservoir via sterile tubing
- Connect chip outlet to waste collection vessel
- Prime the system with sterile PBS to remove air bubbles
- Verify all connections are secure and leak-free

**Step 2: Cell Seeding**
- Prepare cell suspension at optimal density (1-5x10^5 cells/mL)
- Seed cells into each branch culture unit through the open access ports
- For 3D cultures, mix cells with ECM (Matrigel) before seeding
- Incubate statically at 37 C for 4-6 hours to allow attachment

**Step 3: Gradient Configuration (Optional)**
- For drug gradient experiments, connect gradient generator upstream
- Configure flow rates to achieve desired concentration ratios
- Typical gradient: 1:3:10:30:100:300 across 6 branch units
- Verify gradient profile using a fluorescent tracer before adding cells

**Step 4: Perfusion Culture**
- Set flow rate to 20-100 uL/min depending on cell type and experiment duration
- Use a syringe pump or peristaltic pump for stable flow
- Change medium reservoir every 24-48 hours
- Monitor cell viability and morphology daily by microscopy

**Step 5: Endpoint Analysis**
- Collect perfusate samples for biomarker or metabolite analysis
- Perform live/dead staining (Calcein-AM/EthD-1) for viability assessment
- Fix and stain cells for immunofluorescence analysis
- Extract cells for RNA/protein analysis if needed