Incorporation of well-dispersed calcium phosphate nanoparticles into PLGA electrospun nanofibers to enhance the osteogenic induction potential

Abstract

Poly(lactide-co-glycolide) (PLGA) electrospun composite nanofibers were fabricated to mimic bone extra cellular matrix for applications in bone tissue engineering. Poly(acrylic acid) modified Zn-doped calcium phosphate (PAA-CaP/Zn) nanoparticles were first synthesized. PAA was selected because of the strong bonding ability with calcium and Zn was incorporated to enhance the bioactivity. PAA-CaP/Zn nanoparticles were well dispersed with a hydrodynamic size of 184 nm; the presence of Zn was confirmed and the composition was similar to hydroxyapatite. These nanoparticles were non-cytotoxic against adipose derived stem cells from rats (rADSC) at 0.1 mg ml⁻¹ based on an extraction assay and direct contact method. The nanoparticles were further entrapped into PLGA nanofibers. All electrospun membranes were composed of smooth fibers and for composite membranes, nanoparticles were homogeneously distributed in the fiber matrix. Furthermore, the tensile strength was increased with compromised elasticity, while the degradation was retarded and the biomineralization property was enhanced due to the presence of nanoparticles. rADSC proliferated very well on composite membranes and the one with 5% nanoparticles (P-5) demonstrated the highest osteogenic induction effect as significantly more calcium was deposited after osteogenic induction for 21 days. Sample P-5 was the most suitable for applications in bone tissue engineering.