Highly interconnected macroporous structures made from starch nanoparticle-stabilized medium internal phase emulsion polymerization for use in cell culture

A highly interconnected uniform pore structure was prepared through polymerization of medium internal phase Pickering emulsion, called polyMIPPE, are reported. Citric acid crosslinked starch nanoparticle (CSTN) with particle size of 50 nm, as an amphiphilic pH-sensitive particulate stabilizer, was used to prepare stable sunflower oil-in-water emulsions. The polyMIPPEs were obtained through the copolymerization of acrylamide (AM) with N,N′-methylenebisacrylamide (MBAA) in the continuous phase followed by extraction of internal phase. The effect of main parameters such as pH, CSTN and AM content on the size and size distribution of the emulsion droplets as well as the pore size and interconnectivity of the related polyMIPPEs were investigated. Results showed that the best interconnected pore structure (with a pore size of 6.2 μm, pore throat size of 2.0 μm, pore volume of 61% and porosity of 80%) was obtained for the sample included 0.7 wt% of CSTN, 3.75 M of AM, AM/MBAA molar ratio of 9.14 and oil volume fraction of 62.5%. It was concluded that the employed force caused by volume contraction during the polymerization is high enough to tear films between the pores to create large pore throats, namely higher interconnectivity. Preliminary cell culture and biocompatibility assessments with human neuroblastoma cells indicated that the prepared porous materials have no significant detrimental effect on cell adhesion. It is believed that these materials could be presented as a promising culture substrates for various biomedical applications.