Synthesis and characterization of CaO-loaded electrospun matrices for bone tissue engineering

Abstract

Objectives To synthesize and characterize biodegradable polymer-based matrices loaded with CaO-nanoparticles for osteomyelitis treatment and bone tissue engineering. Materials and methods Poly(ε-caprolactone) (PCL) and PCL/gelatin (1:1, w/w) solutions containing CaO nanoparticles were electrospun into fibrous matrices. Scanning (SEM) and transmission (TEM) electron microscopy, Fourier Transformed Infrared (FTIR), Energy Dispersive X-ray Spectroscopy (EDS), contact angle (CA), tensile testing, and antibacterial activity (agar diffusion assay) against Staphylococcus aureus (S. aureus) were performed. Osteoprecursor cell (MC3T3-E1) response (i.e., viability and alkaline phosphatase expression/ALP) and infiltration into the matrices were evaluated. Results CaO nanoparticles were successfully incorporated into the fibers, with the median fiber diameter decreasing after CaO incorporation. The CA decreased with the 0addition of CaO, and the presence of gelatin made the matrix very hydrophilic (CA = 0°). Increasing CaO concentrations progressively reduced the mechanical properties (p≤0.030). CaO-loaded matrices did not display consistent antibacterial activity. MC3T3-E1 cell viability demonstrated the highest levels for CaO-loaded matrices containing gelatin after 7 days in culture. An increased ALP expression was consistently seen for PCL/CaO matrices when compared to PCL and gelatin-containing counterparts. Conclusions Despite inconsistent antibacterial activity, CaO nanoparticles can be effectively loaded into PCL or PCL/gelatin fibers without negatively affecting the overall performance of the matrices. More importantly, CaO incorporation enhanced cell viability as well as differentiation capacity, as demonstrated by an increased ALP expression. Clinical significance CaO-loaded electrospun matrices show potential for applications in bone tissue engineering.