General Method for Generating Circular Gradients of Active Proteins on Nanofiber Scaffolds Sought for Wound Closure and Related Applications

• Type of Material: Article
• Authors: Tong Wu, Emory University; Jiajia Xue, Emory University; Haoxuan Li, Emory University; Chunlei Zhu, Emory University; Xiumei Mo, Donghua University; Younan Xia, Emory University
• Language: English
• Date: 2018-03-14
• Publisher: ACS Publications
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: 2018
• Final Published Version (URL): http://dx.doi.org/10.1021/acsami.8b00129
• Title of Journal or Parent Work: ACS Applied Materials and Interfaces
• Volume: 10
• Issue: 10
• Start Page: 8536
• End Page: 8545
• Grant/Funding Information: This work was supported in part by a grant from the NIH (R01 EB020050) and startup funds from the Georgia Institute of Technology. As a jointly supervised PhD candidate from Donghua University, T.W. was also partially supported by a fellowship from the China Scholarship Council.
• Keywords: wound dressing; radially aligned nanofibers; Cell Movement; Laminin; Tissue Scaffolds; neurite extension; Ganglia, Spinal; Nanofibers; active protein gradient; Neurites; cell migration
• Research Categories: Biology, General; Biology, Cell

Abstract

Scaffolds functionalized with circular gradients of active proteins are attractive for tissue regeneration because of their enhanced capability to accelerate cell migration and/or promote neurite extension in a radial fashion. Here, we report a general method for generating circular gradients of active proteins on scaffolds composed of radially aligned nanofibers. In a typical process, the scaffold, with its central portion raised using a copper wire to take a cone shape, was placed in a container (upright or up-side-down), followed by dropwise addition of bovine serum albumin (BSA) solution into the container. As such, a circular gradient of BSA was generated along each nanofiber. The bare regions uncovered by BSA were then filled with an active protein of interest. In demonstrating their potential applications, we used different model systems to examine the effects of two types of protein gradients. While the gradient of laminin and epidermal growth factor accelerated the migration of fibroblasts and keratinocytes, respectively, from the periphery toward the center of the scaffold, the gradient of nerve growth factor promoted the radial extension of neurites from the embryonic chick dorsal root ganglion. This method for generating circular gradients of active proteins can be readily extended to different types of scaffolds to suit wound closure and related applications that involve cell migration and/or neurite extension in a radial fashion.