A high-throughput microfluidic method for fabricating aligned collagen fibrils to study Keratocyte behavior.

Area of Science:

• Biomaterials Engineering
• Cell Biology
• Tissue Engineering

Background:

• Keratocytes in the corneal stroma interact with aligned type I collagen fibrils.
• The topography of the corneal stroma influences keratocyte behavior.

Purpose of the Study:

• To develop a microfluidic method for depositing aligned type I collagen fibrils.
• To investigate the effect of collagen fibril density and alignment on keratocyte behavior.
• To create a platform for studying the combined influence of topographical and soluble cues on cell behavior.

Main Methods:

• A high-throughput microfluidic system was used to deposit aligned type I collagen fibrils onto glass coverslips.
• Substrates were integrated into a PDMS microwell culture system for high-resolution imaging.
• Wide-field fluorescence and differential interference contrast microscopy were employed.
• Primary normal rabbit keratocytes (NRK) were cultured on collagen-coated substrates with and without platelet-derived growth factor (PDGF).

Main Results:

• Collagen fibril density depended on perfusion shear rate and time, while alignment was consistent across shear rates.
• NRK cells cultured on high-density aligned collagen fibrils and PDGF showed elongated, co-aligned morphology.
• NRK cells on low-density aligned collagen fibrils exhibited no preferential orientation.

Conclusions:

• The microfluidic method provides an effective platform for generating aligned collagen substrates.
• Collagen fibril topography significantly influences keratocyte orientation in response to soluble factors like PDGF.
• This approach facilitates the study of complex cell-environment interactions.