Enhanced mechanical properties and cell separation with thermal control of PIPAAm-brushed polymer-blend microfibers
Kenichi Nagase, Risa Shukuwa, Hironobu Takahashi, N. Takeda, Teruo Okano
Abstract
. These polymer-blend microfibers enabled the preparation of thin, dense mats that were superior in the experimental handling of cell separation. Poly(N-isopropylacrylamide) (PIPAAm) brushes were grafted via surface-initiated atom transfer radical polymerization from the initiation sites of PVBC in the polymer-blend microfiber substrates. The microfiber in a 25 : 75 ratio of PVBC : PBMA had a reasonable amount of the initiation sites and superior mechanical properties. The PIPAAm-brushed microfibers of the 25 : 75 blend substrate were capable of temperature-modulation, both in terms of wettability and cell separation. Among the normal human dermal fibroblasts (NHDFs), human umbilical vein endothelial cells (HUVECs), and human skeletal muscle myoblasts (HSMMs), HUVEC cells showed significantly poor adhesion on fibers at 37 °C; they were separated from adhered NHDF and HSMM cells in the initial step. Reducing the temperature to 20 °C remarkably detached NHDF cells, allowing their separation from HSMM cells. Compared with the PIPAAm-brushed PVBC homopolymer microfibers, these cell-separating functions were enhanced in the thermoresponsive PBMA-rich polymer-blend microfibers, probably ascribed to the properties of PBMA and the moderate density of the PIPAAm-brush. Thus, the developed microfibers could be useful for temperature-modulated cell separation systems.