Interfacial modification of hydrogel composite membranes for protein adsorption with cavitands as nano molecular containers.

• PNIPAm-based HCM with cavitands as nanocontainers was developed for protein absorption. • The hydrogel structure is modified by cavitands and validated by MD simulation. • Fabricated HCM exhibits good structural stability and robust BSA separation performance. Protein adsorption is of great significance for bioengineering, biomedicine, drug release, etc. Herein, poly- N -isopropylacrylamide (PNIPAm) and polyethylene glycol diacrylate (PEGDA) based hydrogel materials were used to introduce self-synthesized cavitands with pore cage structures and hydrophobic characteristics to construct high-efficiency hydrogel composite membrane (HCM) for the adsorption of bovine serum albumin (BSA). The hydrophobic cavitand cage can improve the interfacial polymerization process by impacting the monomer diffusion and then modifying the interface properties of the hydrogel molecular network, which is validated by the molecular dynamic simulation. The adsorption mechanism can be interpreted as the reorganization of the polymer pores using the cavitands, and hence the surface charge and hydrophobic property consequently changed, which is consistent with the measurement results as well as validated by the molecular dynamic simulation. Thus, the fabricated HCM exhibits good structural stability, thermal stability, and robust BSA adsorption performance. The results indicated that the developed HCM materials can be promising candidates for effective protein separation. [ABSTRACT FROM AUTHOR]