3D micromorphology producing within poly(lactic acid) skeleton using room-temperature Ionic liquids: From particulate, fibrous or porous scaffolds to beads

Abstract

We describe herein a three-dimensionally diverse micropatterning of poly(lactic acid), as a biopolymer, using 1-butyl-3-methylimidazolium-based room-temperature ionic liquids (bmim-based RTILs), [bmim]X (X = SbF6, PF6, NTf2, Cl). Utilizing the hydrophobic bmim-based RTILs, [bmim]X (X = SbF6, PF6, NTf2) and a phase separation technique, we were able to produce white and opaque membranes with a three-dimensional structure closely packed with particles (10-50 μm in diameter). The particlulate structure, made by the assistance of [bmim]NTf2 and DCM, interestingly transformed to a fibrous structure by using a cosolvent, e.g., DCM/CF3CH 2OH. When we used an increased amount of [bmim]NTf2, the particles were effectively detached and macrosized (100-500 μm in diameter) and the oval-shaped beads were obtained in a powder form. By varying the counter-anion type of the imidazolium-based RTIL, for example from NTf2 ? to Cl?, the particulate 3D-morphology was once more transformed to a porous structure. These reserch results could be potentially useful, as a method to fabricate particulate scaffolds, fibrous or porous scaffolds, and beads as a biopolymer device in diverse fields including drug delivery, tissue regeneration, and biomedical engineering.