Peptide grafting strategies before and after electrospinning of nanofibers

Nanofiber films produced by electrospinning currently provide a promising platform for different applications. Although nonfunctionalized nanofiber films from natural or synthetic polymers are extensively used, electrospun materials combined with peptides are gaining more interest. In fact, the selection of specific peptides improves the performance of the material for biological applications and mainly for tissue engineering, mostly by maintaining similar mechanical properties with respect to the simple polymer. The main drawback in using peptides blended with a polymer is the quick release of the peptides. To avoid this problem, covalent linking of the peptide is more beneficial. Here, we reviewed synthetic protocols that enable covalent grafting of peptides to polymers before or after the electrospinning procedures to obtain more robust electrospun materials. Applications and the performance of the new material compared to that of the starting polymer are discussed. Statement of significance The primary aim of this review is to provide an overview of the main use of peptides in electrospinning. The reviewed literature primarily emphasizes the technical aspects and gen- eral principles of electrospinning or the use of plant- or animal-derived proteins or synthetic polymers for generating elecrospun scaffolds. A special focus is given to applications, largely from specific biomedical fields (tissue engineering, drug delivery, and biomedical materials). The combination of peptides and polymers is a very interesting tool to improve the perfor- mance of the material. Different strategies are applied to integrate peptides: coating, blending, and covalent grafting are mostly used. The present review focuses on the methodologies for covalently linking peptides to polymers in order to functionalize the fibers. The review covers studies published from 2010 to date.