Ethylene glycol-based thermoresponsive block copolymer brushes with cell-affinity peptides for thermally controlled interaction with target cells

Abstract

Tissue engineering has recently attracted attention as a potential remedy for intractable diseases. To be effective, such treatments require cell separation methods that do not modify cellular surfaces. In this study, we developed cell separation materials using ethylene glycol-based thermoresponsive block copolymer brushes and cell-affinity peptides. A poly(2-hydroxyethyl methacrylate-co-propargyl acrylate) (P(HEMA-co-PgA)) brush was grafted onto a glass substrate through atom transfer radical polymerization (ATRP). Subsequently, poly(2-(2-methoxyethoxy)ethyl methacrylate) (PMEO2MA), P(MEO2MA-co-HEMA-co-poly(ethylene glycol) methacrylate [PEGMA]), or P(MEO2MA-co-PEGMA) was grafted onto the P(HEMA-co-PgA) brush-coated substrates through a second ATRP. A Gly-Gly-Gly-Arg-Glu-Asp-Val (GGGREDV) peptide was conjugated to the copolymer brush via a click reaction. The prepared copolymer brushes exhibited thermoresponsive properties. The block copolymer brushes having the P(MEO2MA-co-HEMA-co-PEGMA) and P(MEO2MA-co-PEGMA) segment exhibited effective human umbilical vein endothelial cells (HUVECs) adhesion and normal human dermal fibroblasts (NHDFs) repulsion at 37 °C. By reducing temperature to 20 °C, adherent HUVECs were successfully recovered from the copolymer brushes. Using these copolymer brushes, HUVECs were separated from contaminant NHDFs and smooth muscle cells with these simple changes in temperature. The development of thermoresponsive ethylene glycol-based copolymer brushes with affinity peptides could be a useful cell separation material for tissue engineering applications.