Paper BI+NC-ThM6
Fabrication and Testing of Electrospun Novel Biodegradable Polyurethane Scaffolds

Thursday, October 23, 2008, 9:40 am, Room 202

Synthesis and fabrication of biomaterials that can temporarily mimic the native tissue is a lofty aim in Tissue Engineering. It is also paramount in Regenerative Medicine material research. Such a biomaterial could be formed into scaffolds and be temporary replacements of tissues or for other internal biomaterial corporal needs. Our work here is on the use of a novel biodegradable polyurethane (BPU) that was electrospun and fabricated into tubes. Once fabricated, smooth muscle cells (RASMC) were ink-jet printed onto the same scaffolds and tested for degrees of cell alignment BPU are biopolymers that are designed to mimic the elasticity and memory of native tissue. These biopolymers can be designed to fit the application. This BPU was synthesized from methylene di-p-phenyl-diisocyanate (MDI), polycaprolactone diol (PCL-diol) and N, N-bis (2-hydorxyethyl)-2-aminoethane-sulfonic acid (BES), serving as a hard segment, soft segment and chain extender respectively. The BPU was then electrospun into nanofibers and formed small diameter (4 mm) blood vessels. The blood vessels were electrospun at various extrusion rates to determine optimum pore size and fiber diameters. This was accomplished by SEM imaging. The mechanical testing included tensile and burst pressure testing to determine if the scaffold could withstand extreme physiological conditions. Burst pressure testing results were from 1600-2900 mm Hg. Fiber diameters were in the 700-1000 nm range. Pore sizes were in the 50-90 um range. Mechanical testing results indicated a elongation of 620+/-120% with memory. The mechanical testing indicated that these scaffolds could withstand extreme mechanical physiological conditions well exceeding what they would experience in vivo. The imaging indicated fiber formation that could mimic an extracellular matrix or act as an internal physical barrier. Lastly, ink-jet printing was used as a cell placement method to control the location of cells on material. Cell printing was used to determine if RASMC cell alignment was possible and to what degree patterns could be printed to conjure alignment on the fibrous scaffolds. Histological results of the RASMC patterns on the electrospun scaffolds will be presented.