Physico-chemical and biological properties of electrospun poly-L-lactic acid/hydroxyapatite nano-composite scaffold for bone regeneration

The main goal of tissue engineering is to design scaffolds with the suitable microenvironment, prominent mechanical properties, adequate biocompatibility, and biodegradability. In the present study, Poly-L-lactic acid (PLLA)/10% hydroxyapatite (HA) nano-composite (PLLA/HA) scaffold and pure PLLA scaffold were fabricated via electrospinning technique. They were then assessed for their potential as substrates for the cell culture. The scaffolds were characterized by scanning electron microscope, thermogravimetric analysis, differential thermal analysis, and fourier transform infrared spectroscopy. The results showed the dispersion and integration of HA nanoparticles in the composite scaffold. Pore size distribution measurements indicated that the scaffold pore size in terms of Ferret diameter varies between 0.1 and 22.0 µm. In vitro degradation behavior of the scaffold in phosphate buffered saline (PBS) was obtained by measuring water uptake, weight loss, and pH change of the PBS during the degradation period. We observed that the degradation of the scaffold could be markedly accelerated by HA nanoparticle (10%). It was also shown that acidification of the PBS due to the PLLA degradation is suppressed by the HA nanoparticles. Finally, human umbilical-cord-derived mesenchymal stem cells (hUC-MSCs) were used to evaluate the cellular support of the composite scaffolds. The presence of HA nanoparticles in the PLLA fibrous scaffolds resulted in promoting the attachment and the proliferation of the hUC-MSCs. This study suggests that the PLLA/HA scaffold could be the material of choice for functional bone tissue engineering.