Figure 6.

Protein repellency mechanism for a hydrophilic, brush-like grafted polymer [210,213,219]. Protein adsorption onto grafted PEG results in the release of the hydration barrier from both the polymer and the protein. This process increases the entropy for water, but is outweighed by a decrease in conformational entropy for the polymer. The net result is entropically unfavourable for protein adsorption. (ΔH_Ads) for the protein–polymer interaction can either be favourable or unfavourable depending on the paired species [210,222]. More strongly bound water results in less favourable protein adsorption.