Electrospun fiber properties influence the location and determine the alignment of adhesion sites

M.C. Cross, D.B. Khadka, D.T. Haynie
University of South Florida, US

Keywords: fibroblasts, flexural rigidity, focal adhesions, polypeptides, statistical mechanics

Summary:

Electrospun fibers made of proteins are currently of considerable interest in biomedical engineering research. Potential applications of the materials include implantable device coatings, tissue engineering scaffolds and drug delivery depots (1). Proteins studied in this context have included fibronectin, collagen and silkworm silk (2). Typically, however, utilization of a harsh organic solvent has been necessary for polymer solubilization and processing, for instance, hexafluoroisopropanol or toluene. Defining features of electrospinning research in our work include an emphasis on peptide design, recombinant polymer production, materials characterization and technology development. In previous work, we found normal human dermal fibroblasts (NHDFs) to associate preferentially with fibers electrospun from an aqueous feedstock of a model peptide, synthetic co-poly(L-glutamic acid4, L-tyrosine1) (PLEY) (3). We then considered possible underlying reasons for the behavior, including differences in surface density of charge and serum protein binding (4). Here, seeking a more complete explanation of the phenomenon, we have analyzed focal adhesions (FAs) formed by NHDFs on PLEY fibers.