Enhanced osteogenesis and antibacterial activity of bioactive glass-coated, epsilon-poly-L-lysine-loaded, polycaprolactone 3D-printed scaffolds with potential use in bone tissue engineering.

OBJECTIVE

This study evaluated the structural properties and biological in vitro performance of 3D-printed polycaprolactone (PCL) scaffolds, coated with bioactive glass (BG) and functionalized with epsilon-poly-L-lysine (EPL) when co-cultured with rat bone marrow mesenchymal stem cells.

MATERIAL AND

METHODS

The physicochemical characterization included scanning electron microscopy, energy dispersive spectroscopy, x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and degradation kinetics. The biological characterization assessed antibacterial activity using a disk diffusion assay, cell viability of rat bone marrow mesenchymal stem cells with confocal laser scanning microscopy, cell proliferation and cytotoxicity with tetrazolium assay and relative gene and protein expression through reverse transcriptase quantitative polymerase chain reaction and western blot.

RESULTS

The physicochemical characterization showed a successful and homogeneous distribution of the ceramic component and confirmed EPL-loading. The PCL-BG-EPL scaffolds demonstrated antibacterial activity against Staphylocccus aureus for up to 7 days. Cell proliferation was significantly higher for PCL-BG and PCL-BG-EPL scaffolds, but cytotoxicity also increased in both groups when comparing day 3 and day 7. The osteogenic potential was enhanced for BG-coated scaffolds, with an upregulation of Alpl, Opn, and Col1a1 genes when compared to controls. However, no significant differences were detected for protein synthesis among the three groups.

CONCLUSIONS

Composite scaffolds exhibited favorable technical properties and superior biological performance over pure PCL scaffolds.