title: Fibronectin adsorption on functionalized electrospun polycaprolactone scaffolds: experimental and molecular dynamics studies.
abstract: Designing scaffolds to modulate protein adsorption is a key to building advanced scaffolds for tissue regeneration. Protein adsorption to tissue engineering scaffolds is critical in early cell attachment, survival, and eventual proliferation. The goal of this study is to examine the effect of functionalization on fibronectin adsorption to electrospun polycaprolactone (PCL) scaffolds through experimentation using fluorescently labeled fibronectin and to couple this experimental data with analysis of interaction energies obtained through molecular dynamics (MD) simulations to develop a better understanding of the adsorption process. This study is the first to analyze and compare experimental and MD simulation results of fibronectin adsorption on functionalized electrospun PCL scaffolds. Electrospun nanofiber PCL scaffolds were treated with either 1 N NaOH (hydrolyzed) or 46% hexamethylenediamine (HMD) (aminated) solution to be compared with untreated (control) scaffolds. We found that aminated PCL scaffolds experimentally adsorbed more fibronectin than control scaffolds, whereas hydrolyzed scaffolds showed decreased adsorption. MD simulations carried out with NVT ensemble at a temperature of 310 K indicated a higher work of adhesion for both functionalized scaffolds over control. Also, the simulations revealed different conformations of fibronectin on each scaffold type after adsorption, with the arginine-glycine-aspartic acid sequence appearing most accessible on the aminated scaffolds. This suggests that functionalization affects not only the quantity of protein that will adsorb on a scaffold but how it attaches as well, which could affect subsequent cell attachment.
authors.affiliation: Biomedical Engineering and Biotechnology Program, University of Massachusetts Dartmouth, North Dartmouth, Massachusetts, 02747.
authors.forename: Shawn
authors.initials: S
authors.lastname: Regis
authors.forename: Sina
authors.initials: S
authors.lastname: Youssefian
authors.forename: Manisha
authors.initials: M
authors.lastname: Jassal
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Phaneuf
authors.forename: Nima
authors.initials: N
authors.lastname: Rahbar
authors.forename: Sankha
authors.initials: S
authors.lastname: Bhowmick
mesh_terms: D000327:Adsorption; D005353:Fibronectins / Q000737:chemistry*; D006801:Humans; D056004:Molecular Dynamics Simulation; D011091:Polyesters / Q000737:chemistry*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D005353:Fibronectins; D011091:Polyesters; C016240:polycaprolactone
keywords: MD simulations; electrospun PCL; fibronectin; functionalization; protein adsorption