Polymer-peptide conjugate hydrogels:towards controlled drug delivery

Peptide-based materials exhibit remarkable supramolecular self-assembling behavior, owing to their overwhelming propensity to from hierarchical structures from a-helices and ß-sheets. Coupling a peptide sequence to a synthetic polymer chain allows greater control over the final physical properties of the supermolecular material. So-called ‘polymer-peptide conjugates’ can be used to create biocompatible hydrogels which are held together by reversible physical interactions. Potentially, the hydrogels can be loaded with aqueous-based drug molecules, which can be injected into targeted sites in the body if they can exhibit a gel-sol-gel transition under application and removal of a shear force. In this review, we introduce this topic to readers new to the field of polymer-peptide conjugates, discussing common synthetic strategies and their self-assembling behavior. The lack of examples of actual drug delivery applications from polymer-peptide conjugates is highlighted in an attempt to incite progress in this area.

Facile synthesis of polymer-peptide conjugates via direct amino acid coupling chemistry

Polymer-peptide conjugates (also known as biohy-brids) are attracting considerable attention as injectable materials owing to the self-assembling behavior of the peptide and the ability to control the material properties using the polymer component. To this end, a simple method for preparing poly(ethylene oxide)-oligophenylalanine polymer-peptide conjugates (mPEOm-F n-OEt) using isobutylchloroformate as the activating reagent has been identified and developed. The synthetic approach reported employs an industrially viable route to produce conjugates with high yield and purity. Moreover, the approach allows judicious selection of the precursor building blocks to produce libraries of polymer-peptide conjugates with complete control over the molecular composition. Control over the molecular make-up of the conjugates allows fine control of the physicochemical properties, which will be exploited in future studies into the prominent self-assembling behavior of such materials. © 2013 Wiley Periodicals, Inc.

Individual differences in cognitive style and their effects on task and social orientations of self-managed work teams

When assembling self-managing work teams, the personalities of team members are often overlooked. One personality variable known to be critical for effective decision making in teams is cognitive style. This study sought to examine how differences and similarities in analytic/intuitive cognitive styles affected the behavior of team members on the task/emotionally expressive dimension identified by Bales. As hypothesized, intuitive individuals and homogeneous intuitive teams were found to initiate more social-emotional acts. Contrary to expectations, intuitive rather than analytic individuals and homogeneous intuitive rather than analytic teams engaged in more task-oriented behaviors. Teams also tended to select intuitive individuals as leaders. The possibility that different combinations of styles may be important for overall team effectiveness was subsequently discussed, and it was suggested that this may depend on whether the nature of the work environment is relatively well structured and mechanistic or relatively unstructured and organic.