Preparation and characterization of biomimetic PLLA/Hydroxyapatite nanofibrous scaffolds for bone tissue engineering

Abstract

Utilization of materials as tissue engineering scaffolds with composition and structure mimicking those of bone matrix is regarded as a promising approach in treatment of bone defects. Human bone is constituted of apatite nanocrystallines and collageneous fibers, performing biological and mechanical functions in a highly effective way. In order to direct bone formation in tissue engineering strategies, the 3D scaffolds should possess adequate mechanical strength as well as osteochonductivity. Poly(L-lactide) (PLLA) is one of good candidates as a bone tissue engineering scaffold due to biodegradability and biocompatibility. HA has been used in various biomedical fields including dental materials, hard tissue paste, and bone substitute, since HA have sufficiently good mechanical properties with superior osteoconductivity. In this study, we developed PLLA/HA composite scaffolds in nanofibrous formulation using an electrospinning process. The microstructure and physical and mechanical properties of the PLLA/HA nanofiber composites with different concentrations of HA (0 wt%, 5 wt% and 20 wt%) were studied by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), Ramam spectroscopy, thermogravimetric analysis (TGA), and instron. SEM images showed that HA nanoparticles anchored to the composite fibers and it became rougher and uneven with increase in HA content. FT-IR absorbance patterns for PLLA/HA nanofibers showed typical peaks for HA, particularly phosphate groups. Other analytical methods supported that HA were successfully incorporated within the fibers and homogenously distributed.