Structure and Rheology of Hydrogels: Applications in Drug Delivery

Recent advances in synthetic chemistry has led to the increasingly sophisticated design and preparation of biofunctional polymeric surfaces and materials. In this regard, synthetic poly-(N-substituted glycine) “peptoids” which mimic the structure and function of peptides play an important role, since they may attain functionalities similar to natural biopolymers. This chapter reviews efforts by our group and others to develop “antifouling” peptoid coatings that resist the nonspecific and undesired adsorption of proteins and attachment of mammalian and microbial cells. We have found that the simplest peptoid—polysarcosine—has been found to be well hydrated and therefore well-suited for antifouling applications. We show that the synthetic convenience of peptoids in general greatly facilitates studies on how polymer chain length, chain density, sidechain chemistry, and specific peptoid sequences may control surface interactions. Indeed, specific peptoids and sequence arrangements have been found to exhibit long-term antifouling properties and excellent resistance against different strains of bacteria. Addition of simple sugar groups to peptoid chains may further enhance resistance against bacterial attachment. Combined with peptoid’s resistance against enzymatic degradation, antifouling peptoids have excellent potential in biomedical applications. These range from coatings of catheters and other biological devices to biosensing and nanomedicine that require a non-fouling interface to achieve improved device performance.