(684d) Novel Electrospun Fibers with Large Pore Sizes for Tissue Regeneration

Electrospinning technique in textile technology has recently emerged as a novel technique for tissue regeneration because it is versatile and relatively economical to manufacture nanofibers similar to natural extracellular membrane. A major problem in electrospinning technique is the lack of generating structural features necessary for building 3D tissue. Polymeric structures of electrospun fibers have tiny pores compared to human cells, and do not allow cells to infiltrate into the layers below the surface. In this study, we describe a novel fabrication method of electrospun fiber made of polycaprolactone (PCL) and gelatin with an innovative collector to fabricate the thin layer of fibers with large pore sizes.

The novelty of this technique is the collector which allows the thin layer of nano or micro sized fibers with large pore size very suitable for tissue regeneration. Also, novel deposit processes (sequential and simultaneous deposit) facilitate formation of composite structure of PCL and gelatin. The fiber size and pore size were evaluated using scanning electron microscope, inverted light microscope, CCD camera, and Sigma Scan Pro software. In vitro cell study was carried out with human fibroblasts in serum free media to evaluate the usage of the thin layer for tissue regeneration.

Micrograph of polymeric structure showed that pore size is at least 30 micrometers which is large enough for cell to infiltrate into the surface of 3D scaffold. The fiber size is up to 5 micrometers similar to published reports. The fiber size can be controlled by varying process and solution parameters. The fibers appeared intact without any observable distortion, suggesting no mechanical damage by handling and fibers still keeps their polymeric structure even after hydration. The cell staining study using DAPI and Alexa phalloidin shows that cells are healthily attached onto the surface of fibers. Thus, the innovative thin layer of fibers with large pore size has a potential as 3D scaffold for tissue regeneration.