Preparation and Characterization of Thermoresponsive Poly(N-isopropylacrylamide-co-acrylic acid)-Grafted Hollow Fe3O4/SiO2 Microspheres with Surface Holes for BSA Release

Abstract

Thermoresponsive P(NIPAM-AA)/Fe3O4/SiO2 microspheres with surface holes serving as carriers were prepared using p-Fe3O4/SiO2 microspheres with a thermoresponsive copolymer. The p-Fe3O4/SiO2 microspheres was obtained using a modified Pickering method and chemical etching. The surface pore size of p-Fe3O4/SiO2 microspheres was in the range of 18.3 nm~37.2 nm and the cavity size was approximately 60 nm, which are suitable for loading and transporting biological macromolecules. P(NIPAM-AA) was synthesized inside and outside of the p-Fe3O4/SiO2 microspheres via atom transfer radical polymerization of NIPAM, MBA and AA. The volume phase transition temperature (VPTT) of the specifically designed P(NIPAM-AA)/Fe3O4/SiO2 microspheres was 42.5 °C. The saturation magnetization of P(NIPAM-AA)/Fe3O4/SiO2 microspheres was 72.7 emu/g. The P(NIPAM-AA)/Fe3O4/SiO2 microspheres were used as carriers to study the loading and release behavior of BSA. This microsphere system shows potential for the loading of proteins as a drug delivery platform.

Thermosensitive Metal Chelation Dual-Template Epitope Imprinting Polymer Using Distillation–Precipitation Polymerization for Simultaneous Recognition of Human Serum Albumin and Transferrin

“…pNIPAM has a low critical solution temperature (LCST). When the temperature is lower than the LCST, the pNIPAM hydrogel is highly swollen, and when the temperature is above the LCST, the hydrogel is at a state of shrinking. , NIPAM has been widely used in molecular imprinting to realize temperature-controlled recognition and release for the target molecule such as organic small molecules and proteins. , However, NIPAM has been rarely used in dual-template epitope imprinting.…”