Protein-based materials aqueous environment function

Adsorption/absorption of biomolecules primarily results in depletion of necessary factors provided by the medium or secreted by the cells. It is an equilibrium-based phenomenon resulting in partitioning of the biomolecules between the PDMS material and the aqueous phase. Consequently, in a fluidic environment, new biomolecules (in the case of those provided by the medium) continuously arrive and are adsorbed/absorbed while a portion of the previously adsorbed/absorbed ones are detached from the PDMS material. As long as there is a sufficient supply of biomolecules in the medium, cell growth is not hampered. However, small molecules and proteins that are secreted by the cells and necessary for control of cellular functions (autocrine and paracrine factors) can potentially be removed to an extent strongly competing with the cellular capacity to excrete them. Secondly, adsorption of proteins, even if they were supplied by the medium and only transiently adsorbed on the hydrophobic surface of PDMS, causes an even more severe problem. The hydrophobic interaction of proteins with PDMS results in their denaturation due to the exposure of the hydrophobic core of the protein. 

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