Electrospun Fibrous Mats As Potential Scaffolds For Tissue Engineering

Surface wettability is critical for optimal application of electrospun fibrous mats as tissue growth scaffolds and wound dressing materials. To enhance the cell attachment, distribution and viability, blending electrospinning of PDLLA with poly(ethylene glycol) (PEG) was investigated in the current study. PDLLA/PEG fibrous mats with a series of PEG contents were fabricated, and the surface characteristics, mechanical properties, and cell-matrix interaction were evaluated for an optimal tissue engineering scaffold. By the addition of PEG the surface hydrophilicity was improved, but fibrous mats were weakened and less elastic. L-929 cell interacted and integrated well with the surrounding fibers containing 20% PEG, which provided significantly better environment for biological activity of cells than do the electrospun PDLLA mats.Diffusional limitation of mass transport has adverse effects on engineering tissues that normally have high vascularity and/or cellularity. The current electrospinning method is not always successful to create micropores to encourage cell infiltration within the scaffold, especially when relatively large-sized pores are required. In this study, a slow rotating frame cylinder was developed as the collector to extend the pore size and increase the porosity of electrospun fibrous scaffolds. Fibrous mats with porosity as high as 92.4% and average pore size of 132.7μm were obtained. HDFs were seeded onto these mats, which were fixed on a cell-culture ring to prevent the shrinkage and contraction during the incubation. The viability test indicated that significantly more HDFs were generated on highly porous fibrous mats. Toluidine blue staining showed that the highly porous scaffold provided mechanical support for cells to maintain uniform distribution. The cross-section observations indicated that cells migrated and infiltrated more than 100μm inside highly porous fibrous mats after 5 days incubation. The immunohistochemistry analysis demonstrated that cells began secreting collagen, which is the main constituent of extracellular matrix. It is supposed that highly porous electrospun fibrous scaffolds could be constructed by this elaboration and may be used for skin tissue engineering.The combination of natural materials and synthetic materials will help improve the biocompatibility and bioactivity of tissue engineering scaffold. In this study, coUagen/PLGA hybrid fibrous mats were fabricated with different collagen contents of 5, 10 and 30 wt % collected on the slow rotating frame cylinder. HDFs were seeded on these mats to determine cell adhesion, morphology and proliferation. Fibroblast cells from green fluorescent protein-transgenic mice were loaded within the fibrous scaffold to show the cell distribution. The results indicated that the increase in the collagen proportion enhanced the cell growth. High-porosity membrane with 30 wt% collagen can not only maintaine the mechanical properties, but also enhnce cell adhesion, growth and proliferation, and there were significant differences with other experimental groups.