Fabrication of biomimetic bundled gel fibres using dynamic microfluidic gelation of phase-separated polymer solutions

Here, we discuss the fabrication of biomimetic bundle-structured gel fibres using a microfluidic device and the rapid cross-linking of a phase-separated polymer blend solution. The products are potential candidates for cell culture scaffolds that mimic artificial tissues. Two naturally derived, biocompatible polysaccharide polymers are the raw materials for the bundled gel fibres, which are approximately 200-400 μm in diameter and consist of 10²-10³ aligned continuous microfibres of 1-3 μm in diameter. They create a composite fibrous material with enhanced toughness and tensile strength because of the unique three-dimensional, cross-linked hierarchic structure. Because the main component of the gel fibre is temperature responsive, the mechanical properties improve at higher temperatures, yet are reversible without collapsing in response to temperature changes. Cell cultures form a cylinder-like shape along the fibre orientation. These unique features would be advantageous for tissue scaffolds as well as other biomaterial applications such as tissue engineering, actuators, drug carriers, and biosensors with the remotely controllable "on-off" properties.