Time-Dependent Self-assembly of Magnetic Particles Tethered Branched block Copolymer for Potential Biomedical Application

Abstract Herein, we demonstrate the time-dependent self-assembly of amphiphilic block copolymer (BCP) and BCP/magnetic particles (MNPs) hybrid material. The structure of the BCP was tailored with a higher amount of hydrophilic polyacrylic acid (PAA) part with a tetra-armed branched structure. A faster way of transformation is observed for hybrid material tethered with MNPs. Electron microscopy observation revealed the intermediate stages of transformation from spherical to tubular morphology via a worm-like phase. The dynamic light scattering (DLS) and atomic force microscopy (AFM) measurements are also supporting the transformation mechanism. The presently developed networks of magnetic micro-tube (MMT) comprise the MNPs at the outer surface of the tube while the inner lumen is enriched with hydrophobic polycaprolactone (PCL) polymer. The driving force of this self-assembly is possibly intra, intermolecular H-bonding and magnetic force of interaction. Moreover, this transformation showed irreversibility in the prolonged-time period. The MMT shows a saturation magnetization of 1.5 emu/g by loading 2.9 wt% of MNPs. The hybrid film shows 88% cell viability and 2.6 times higher cell adhesion characteristics with the HaCaT cell line in comparison to the control sample. The self-assembly structure is expected to have a wide range of potentiality in tissue engineering and angiogenesis application.