Evaluation of Biocompatibility and Reaction of the Immune system of the Rat in Single and Composite Electrospun Nanofiber Structures (PCL/PU) for Tissue Engineering Applications

Aim: Fabrication of biocompatible single and composite nanofiber scaffolds having less interactions in vivo (lack of immune response in the body) and providing optimal conditions for the growth and proliferation of cells.
Material and First, the electrospinning method was used to fabricate three samples of single polycaprolactone (PCL), single polyurethane (PU) and composite PCL/PU (50/50) biopolymer nanofibers. The samples were sterilized with ethylene oxide for 14 hours and implanted under the skin of 12 rats. Also, to examine the growth and proliferation of cells, produced structures were evaluated by the cytotoxicity test (MTT Assay).
Although the rats did not receive antibiotics, localized and systemic reactions and infections of the surgical sites were not observed until the end of the study period. Use of single PCL biopolymer caused negligible edema, fibrosis, and a mild foreign body granuloma. While the PU sample caused the fewest side effects: mainly a negligible edema and moderate fibrosis were observed, but no foreign body granuloma was shown. Also, the PU/PCL sample caused a moderate edema and foreign body granuloma and a mild fibrosis.
Single and composite structures of PCL and PU were all suitable environments for the cell growth and proliferation, as well as the reaction of the immune system in these samples was very low and at a satisfactory level.