Brush-On Fabrication of Suspended PLLA-PEO-PLLA Triblock Copolymer Fibers

Parallel fibers can be rapidly created by manually brushing solvated polymer solutions over arrays of microfabricated pillars. Recently, this technique has been utilized to produce suspended arrays of micron and sub-micron scale fibers consisting of a new triblock copolymer composed of a hydrophilic mid-block of polyethylene oxide (PEO) surrounded by two hydrophobic end groups of poly-L-lactic acid (PLLA). A solution of this polymer in chloroform has been used to fabricate fibers with diameters ranging from 125 nm to >50 μm. Annealing these fibers in water induces the formation of ultrastructural nanoscale pores that can be selectively oriented through variation of the surface treatment. Because the PLLA-PEO-PLLA triblock copolymer is both biocompatible and biodegradable, these arrays of fibers are excellent candidates for biomimetic extracellular matrix (ECM) structures. Additionally, the porous ultrastructure of the fibers may provide a platform for the in situ delivery of growth factors to stimulate endothelial cell proliferation, migration, and lumen formation.