Effect of hydroxyapatite concentration and size on morpho-mechanical properties of PLA-based randomly oriented and aligned electrospun nanofibrous mats

The growing demand for nanofibrous biocomposites able to provide peculiar properties requires systematic investigations of processing-structure-property relationships. Understanding the morpho-mechanical properties of an electrospun scaffold as a function of the filler features and mat microstructure can aid in designing these systems. In this work, the reinforcing effect of micrometric and nanometric hydroxyapatite particles in polylactic acid-based electrospun scaffold presenting random and aligned fibers orientation, was evaluated. The particles incorporation was investigated trough Fourier transform infrared spectroscopy in attenuated total reflectance. The morphology of the nanofibers was analyzed through scanning electron microscopy and it was correlated with the viscosity of polymeric solutions studied by rheological measurements. Scaffolds were mechanical characterized with tensile tests in order to find a correlation between the preparation method and the strength of the mats. The influence of hydroxyapatite particles on the crystallinity of the composites was investigated by differential scanning calorimetry. Finally, cell culture assays with pre-osteoblatic cells were conducted on a selected composite scaffold in order to compare the cell proliferation and morphology with that of polylactic acid scaffolds. Based on the results, we can prove that polylactic acid/hydroxyapatite composites can be one of the biomaterials with the greatest potential for bone tissue regeneration.