Water Structure of PEG Solutions by Differential Scanning Calorimetry Measurements

As this volume attests, poly(ethylene glycol) or PEG is a material of growing importance in the biomedical world. It has been used in free solution as an agent for cell fusion1 and protein precipitation.2 It has also been conjugated to proteins and drugs to reduce immunological responses and control pharmacodynamics.3 Finally, it has been used in biocompatible materials, either as a coating or incorporated into a hydrogel.4 These surfaces are expected to be highly biocompatible because protein adsorption to them is low.4,5 Both the amount of protein adsorption and the magnitude of other biochemical events, such as platelet adhesion, rapidly decline as the PEG molecular weight rises.6,7 This decline is most marked at molecular weights up to 1000, after which the biointeractions tend to level out gradually.