Grafting of Gelatin on Electrospun Poly(caprolactone) Nanofibers to Improve Endothelial Cell Spreading and Proliferation and to Control Cell Orientation

Abstract

We modified the surface of electrospun poly(caprolactone) (PCL) nanofibers to improve their compatibility with endothelial cells (ECs) and to show the potential application of PCL nanofibers as a blood vessel tissue-engineering scaffold. Nonwoven PCL nanofibers (PCL NF) and aligned PCL nanofibers (APCL NF) were fabricated by electrospinning technology. To graft gelatin on the nanofiber surface, PCL nanofibers were first treated with air plasma to introduce -COOH groups on the surface, followed by covalent grafting of gelatin molecules, using water-soluble carbodiimide as the coupling agent. The chemical change in the material surface during surface modification was confirmed by X-ray photoelectron spectroscopy and quantified by colorimetric methods. ECs were cultured to evaluate the cytocompatibility of surface-modified PCL NF and APCL NF. Gelatin grafting can obviously enhance EC spreading and proliferation compared with the original material. Moreover, gelatin-grafted APCL NF readily orients ECs along the fibers whereas unmodified APCL NF does not. Immunostaining micrographs showed that ECs cultured on gelatin-grafted PCL NF were able to maintain the expression of three characteristic markers: platelet-endothelial cell adhesion molecule 1 (PECAM-1), intercellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1). The surface-modified PCL nanofibrous material is a potential candidate material in blood vessel tissue engineering.

Polymeric Nanofibers in Tissue Engineering

“…[1][2][3] By collecting fibers on a rotating mandrel, rather than a flat plate, the fiber orientation can be directed. [23][24][25][26][27] Other variations include coaxial spinning, 28,29 which can create hollow tube nanofibers or fibers with an inner core composed of one material and an outer layer composed of a second material 30 that can be used to alter the chemical 31 or mechanical 31,32 properties of the fibers. Advantages of this technique include the efficiency and simplicity of the procedure, the inexpensive setup, and the ability to control many factors, such as the fiber diameter, orientation, and composition; disadvantages include the use of organic solvents and the limited control of pore structures.…”

“…The gelatin grafting was shown to enhance endothelial cell spreading and proliferation and cells cultured on aligned fibers were found to align in the direction of the fibers. 25 Other approaches have included collagen directly into the electrospinning process, creating collagen-blended P(LLA-CL) fibers, which were shown to promote endothelial cell spreading, attachment, and viability. 86 Similarly, core/ shell nanofibers have been created with gelatin in the shell to promote cell adhesion and proliferation, whereas poly (glycerol sebacate) was used as the core to mimic the mechanical properties of heart muscle.…”

Engineering on the Straight and Narrow: The Mechanics of Nanofibrous Assemblies for Fiber-Reinforced Tissue Regeneration

“…63 Additional studies have modified fiber surfaces to enhance cell binding and=or growth factor retention. [64][65][66] Further, methacrylate-based copolymers have been electrospun to form nanofibrous coatings that can be crosslinked after formation. 67,68 We have recently reported on the electrospinning of several elements of a library of 120 poly(b-aminoester)s that were photo polymerized after formation 69 as well as novel photocrosslinkable and hydrolytically degradable elastomers.…”

Drug loaded homogeneous electrospun PCL/gelatin hybrid nanofiber structures for anti-infective tissue regeneration membranes

“…PCL is extensively studied for controlled drug delivery because of its compatibility with a wide range of drugs and good mechanical properties [19,20],but it often results in low cell adhesion and proliferation and the biodegradation rate of PCL is low. Gelatin, a natural biopolymer derived from partial hydrolysis of native collagen, has many integrin-binding sites for cell adhesion and differentiation [21]. PCL-gelatin hybrid material, a new biomaterial with good biocompatibility and improved mechanical, physical, and chemical properties [22], has been successfully used in various tissue engineering applications [23][24][25].…”