Abstract

Microfluidics-assisted Spinning of Single Micrometer-sized Protein Microfibers Using Alginate as Sacrificial Matrix

Hisataka Hiramatsu, Graduate Student, Chiba University

Microfibers made of bioactive proteins are potentially useful as scaffolds for 3D tissue engineering. Electrospinning is a major strategy to produce such fibers, but fibers obtained by this process are entangled and united each other, narrowing their application range. Here, we propose a wet spinning process to fabricate single micrometer-sized protein microfibers, which can prevent the aggregation and entanglement of the fibers. A precursor solution containing proteins and sodium alginate, a buffer solution, and a gelation solution were continuously pumped introduced into a microchannel. The precursor solution was gelled, forming protein-alginate composite microfibers. After chemically cross-linking the proteins, and removing the sacrificial alginate matrix, we successfully produced single micrometer-sized protein fibers. In addition, parallel production of narrower fibers was demonstrated using multilayered microfluidic devices. As a biomedical application, we encapsulated mammalian cells and the obtained gelatin fibers within hydrogel matrices, and confirmed that the fibers enhanced the cell proliferation whereas maintaining high cell viability. The presented microfluidic process would be useful for producing single micrometer-sized microfibers made of proteins which are applicable to biomedical applications.