Understanding the effects of processing parameters on electrospun fibers and applications in tissue engineering

The effects of molecular weight and atmospheric conditions on the electrospinning process have been investigated. Electrospun polymer microfibers with a nanoporous surface texture have been produced in the presence of humidity. The density of pores, their depth, and their shape have been shown to vary with relative humidity, molecular weight of the polymer, and solvent volatility. Although polystyrene (PS) was investigated in detail, other commodity polymers were also shown to exhibit the nanoporous surface structure under a judicious choice of spinning conditions. The effect of molecular weight on electrospun fiber formation was also studied. It was determined that sufficient chain entanglements are necessary for fiber formation. Molecular weight was also found to affect fiber diameters. Understanding the effects of molecular weight and humidity on electrsospun fibers allows for a :greater understanding of how to control the electrospinning process to meet specific applications needs. Utilizing this knowledge, we have investigated the use of electrospun collagen and gelatin fibers as tissue engineering scaffolds, This study shows that cells readily attach to this unique fiber morphology.