Fabrication and Endothelialization of Collagen-Blended Biodegradable Polymer Nanofibers: Potential Vascular Graft for Blood Vessel Tissue Engineering

Abstract

Electrospun collagen-blended poly(L-lactic acid)-co-poly(epsilon-caprolactone) [P(LLA-CL), 70:30] nanofiber may have great potential application in tissue engineering because it mimicks the extracellular matrix (ECM) both morphologically and chemically. Blended nanofibers with various weight ratios of polymer to collagen were fabricated by electrospinning. The appearance of the blended nanofibers was investigated by scanning electron microscopy and transmission electron microscopy. The nanofibers exhibited a smooth surface and a narrow diameter distribution, with 60% of the nanofibers having diameters between 100 and 200 nm. Attenuated total reflectance-Fourier transform infrared spectra and X-ray photoelectron spectroscopy verified the existence of collagen molecules on the surface of nanofibers. Human coronary artery endothelial cells (HCAECs) were seeded onto the blended nanofibers for viability, morphogenesis, attachment, and phenotypic studies. Five characteristic endothelial cell (EC) markers, including four types of cell adhesion molecule and one EC-preferential gene (von Willebrand factor), were studied by reverse transcription-polymerase chain reaction. Results showed that the collagen-blended polymer nanofibers could enhance the viability, spreading, and attachment of HCAECs and, moreover, preserve the EC phenotype. The blending electrospinning technique shows potential in refining the composition of polymer nanofibers by adding various ingredients (e.g., growth factors) according to cell types to fabricate tissue-engineering scaffold, particularly blood vessel-engineering scaffold.

Polymeric Nanofibers in Tissue Engineering

“…40,43 Molecular structure X-ray diffraction is commonly used to determine the crystal structure of polymer fibers. 15,20,42,52 Often after chemical modification or the attachment of functional groups, the molecular structure is determined using FTIR 42,43,85,86 or nuclear magnetic resonance analysis. 52 …”

“…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. These fibers were shown to support the cardiogenic differentiation of MSCs, indicating the potential of the nanofibers in the repair of myocardium.…”

The Use of Natural Polymers in Tissue Engineering: A Focus on Electrospun Extracellular Matrix Analogues

“…Electrospinning of a blended collagen mixture is not only simpler, but also avoids the slow mass transfer process and uses lesser amounts of chemical reagents. Moreover, the existence of collagen on the surface and inside the structure provides sustained cell recognition signals with polymer degradation, which is crucial for cell function and development [33].…”

“…In a study done by He et al [33], it was demonstrated that collagen type I blended poly (L-lactic acid)-co-poly(ε-caprolactone) [(PLLA-CL), 70:30] biohybrid scaffolds could enhance the viability, spreading and attachment of human coronary artery endothelial cells (HCAECs) and preserve their phenotype. A similar approach was used by Kwon and Matsuda [34] to combine PLLA-CL with collagen type I. Scaffolds blended with collagen were found to increase the attachment, spreading and proliferation of human umbilical vein endothelial cells (HUVECs).…”

Effect of Tissue Specificity on the Performance of Extracellular Matrix in Improving Endothelialization of Cardiovascular Implants

“…At first, along with the identification and separation of ECM components, more and more ECM proteins have been used to modify CVIs, such as fibronectin (FN), laminin (LN), and collagens (Col). 1,10,11 Furthermore, during the construction of an artificial ECM on CVIs, several techniques, including electrostatic spinning and microcontact printing, have been taken to mimic the physical characteristics of the natural ECM. 12,13 Even so, when these artificially constructed ECMs were compared with ECMs deposited in situ by cultured cells, the latter ones could mimic the natural ECM to a much greater extent, and presented far superior biological properties.…”