Protein adsorption on spark plasma sintered 2d-, 3d- and lamellar type mesoporous silicate compacts

The preparation of lamellar type mesoporous silica (MPS) compact through the spark plasma sintering (SPS) and the adsorption/desorption of protein onto MPS compact are reported to be compared with those onto 2d-hexagonal and 3d-cubic type MPS compacts. A lamellar-type MPS powder (MPS-la) was prepared using triblock copolymer, PEO₅PPO₆₈PEO₅, and was compacted in a carbon die and heated at 500°C for 5 min under uniaxial pressure. The products are referred to as MPS-la-500. The MPS compacts keep the lamellar type mesoporous configuration. The adsorbed amount of protein onto MPS-la-500 was 100 mg/g, while that on MPS-la was 130 mg/g, and the former decreased by 23%. However, its decreasing ratio of the protein adsorption on MPS-la-500 was less than those of 2d-hexagonal and 3d-cubic type MPS compacts, which were 73 and 34%, respectively. The released amount of protein into PBS solution from MPS-la-500, which was soaked in the protein solution for 48 h, increased with the soaking time, while those from 2d- and 3d-type MPS compacts reached to plateau for 4 h of soaking. The lamellar type MPS compact was found to be easier to absorb and release proteins, which may be due to the large aperture of the mesoporous configuration.