(745b) Cell-Glued 3D Scaffold of Electrosprayed Fibers with Large Pore Size Using Bottom up Process

Electrospinning has recently emerged as a novel technique for tissue regeneration because it allows fabricating nano and micro sizes of fibers, similar to the characteristic of natural extracellular membrane. A major problem in electrospinning technology is, however, the lack of generating structural features necessary for building 3D tissues. Manmade structures have tiny pores compared to human cells, and do not allow cells to infiltrate into the layers below the surface. Hence, cell growth is restricted to the surface only. To overcome this barrier, we have developed the novel collector plates to allow a thin layer of electrosprayed fibers with large pore sizes. Because of aluminum frame of the thin layer, it is also easy to handle without any mechanical damages. In this study, we address cell-glued 3D scaffold of electrosprayed fibers with large pore size after 30 day cell culture.

Polycarprolactone was used to fabricate electrosprayed fibers using the novel collector or a conventional one. The physical properties of fibers made by novel and conventional collectors were compared using SEM, CCD camera, and Sigma Scan Pro software. Load and extension curve was also confirmed using INSTRON 5542 and Merlin software. Cell culture study of human fibroblast was carried out in single and multiple layers using bottom up process. The cells were cultured in serum media, immobilized, and stained with Alexa phalloidin and DAPI or haematoxylin and eosin (H & E). Then, cell morphology was confirmed using fluorescent inverted microscopy, fluorescent confocal microscopy, and SEM after 1, 4, 7 and 30 day cell culture.

Mirco (Fiber A and B) and nano (Fiber C and D) sized fibers were fabricated under the same conditions except for exchanging novel (A and C) and conventional (B and D) collectors. Physical properties of each pair of fibers were very similar except pore sizes. The pore sizes were 61.75 and 9.95 micrometers for A and B, and 9.14 and 3.21 micrometers for C and D. However, the diameters of fibers were 3.18 and 3.37 micrometers for A and B, and 100 and 350 nanometers for C and D. After cell culture using Fiber A, images of cells in the thin layer were collected. The images showed that cells in single and multiple layers of fibers were growing well not only vertically but also horizontally. Moreover, the three layers after 30 day cell culture were merged into one stable 3D scaffold mainly because cells acted like glue to attach three layers into one layer. Furthermore, cells on and among fibers support the complex structure of cells and fibers becoming stable even after tailoring the aluminum frame of the sample. Thus, we strongly believe that cell-glued 3D scaffold of the novel electrosprayed fibers with large pore size will expand its implications on other cells, fibers, tissues, and organs.