Characterisation of blends between poly(epsilon-caprolactone) and polysaccharides for tissue engineering applications

In this work, bioartificial binary blends between poly(epsilon-caprolactone) (PCL) and a polysaccharide (chitosan (CS) or starch (S)) with different contents of the natural polymer (5-30 wt.%) were produced. Melt-mixing and double-precipitation were the methods used for the obtainment of PCL/S and PCL/CS blends, respectively. Tubular scaffolds were produced from bioartificial blends by melt-extrusion. Physico-chemical characterisation was performed by differential scanning calorimetry analysis (DSC), thermogravimetry (TGA), scanning electron microscopy (SEM), infrared analysis (FTIR-ATR and micro-ATR mapping), atomic force microscopy (AFM) and stress-strain tests. Blends were not miscible, phase-separated systems, showing a homogeneous composition and morphology only at low polysaccharide content (<=10 wt.%). The biocompatibility of bioartificial guides was investigated by culturing NIH-3T3 mouse fibroblasts. Cells response showed the following order: PCL/SNPCLNPCL/CS. For each blend type, biocompatibility increased with decreasing the polysaccharide content. In vitro cell tests using S5Y5 neuroblastoma cells, carried out on the most biocompatible blends, assessed their absence of cytotoxicity towards these model cells of the nervous tissue. Results showed that blends with a low chitosan or starch content (<=10 wt.%) are promising for the regeneration of tissues requiring tubular scaffolds, such as the peripheral nerves.