Mineralized Polyamide66/Calcium Chloride Nanofibers for Bone Tissue Engineering

This study aimed at designing a novel electrospun scaffolding material that structurally and chemically resembles native extracellular matrix for bone tissue engineering. Calcium chloride-complexed polyamide66 (PA66/CaCl₂) and pure PA66 electrospun nanofibers were fabricated by the electrospinning method. Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared (FTIR) spectroscopy were used to investigate the effect of the presence of ionized salt in the polymer solution on the mechanical properties and other properties of the electrospun scaffolds. The results show that addition of CaCl₂ to PA66 solution can achieve an internal modification and improve the tensile strength and modulus of the polymeric electrospun nanofiber. Ca²⁺ uploaded through electrospun fibers could provide nucleation sites for the formation of hydroxylapatite (HA) coating. After mineralization, the tensile strength and modulus of HA/PA66/CaCl₂ scaffolds reach up to 41.33 ± 16.17 MPa and 168.59 ± 42.20 MPa, respectively. LIVE/DEAD assay shows that compared with pure PA66 scaffolds, a greater density of viable MC3T3-E1 cells were seen on the HA/PA66/CaCl₂ scaffolds. Cell Counting Kit-8 results indicate that HA/PA66/CaCl₂ scaffolds displays a more favorable ability to promote MC3T3-E1 cell proliferation and growth than that of the other groups with the prolongation of culture time. These results demonstrate that HA/PA66/CaCl₂ scaffolds that structurally and chemically resemble native bone have a good cytocompatibility, and might be a potential candidate for bone tissue engineering. [Figure: see text] Impact statement In this work, the calcium chloride-complexed polyamide66 (PA66/CaCl₂) hybrid nanofibers were prepared by adding CaCl₂ to the PA66 formic acid solution before electrospinning, and then mineralized by saturated calcium phosphate solution. The findings of this study show that the addition of CaCl₂ could achieve an internal modification, improve the tensile strength and modulus of the polymeric electrospun nanofiber, and provide nucleation sites for biomimetic mineralization. This research provides insight and foundation of application of mineralized PA66/CaCl₂ electrospun scaffolding material that structurally and chemically resembles native extracellular matrix for bone tissue engineering.