Application of Biodegradable Bone Scaffolds Based on Poly(Lactic Acid) / Poly(Glycerol Succinic Acid) Containing Nano-Hydroxyapatite

In this study, a novel nanocomposites based on Polylactic acid (PLA) and Poly(glycerol succinic acid) (PGSU) containing hydroxyapatite nanoparticles was prepared by salt leaching technique. FTIR, 1 H NMR, and 13 C NMR analysis evaluated molecular structures of synthesized PGSU. Prepared scaffolds were examined by FTIR and XRD analysis, and their results showed that possible interactions between PLA, PGSU, and n-HA can be seen, and also, the presence of PGSU decreased the amount of crystallinity. Microstructure analysis revealed that porous 3D structures could be seen on all samples even though interconnect structures on PLA70PGSU30H5 were visible. Dispersion of nanoparticles on the nanocomposite scaffolds was characterized, and their results showed that PGSU having functional groups has helped to dispersion and distribute nanoparticles. The thermal stability of the samples was done at high temperature due to the good interactions between the functional groups of polymer pairs and surface of nanoparticles, especially in samples PLA50PGSU50H5 and PLA70PGSU30H5, which were evaluated in the TGA test. Mechanical properties were done on dry and wet conditions on all of the scaffolds, and results showed that the bulk modulus of scaffolds containing PGSU has decreased and the pressure tolerance in these samples has decreased, but the volumetric strain has increased. Dynamic contact angles showed that the presence of PGSU and n-HA positively affected the hydrophobicity properties of PLA. MTT, Dapi, and cell adhesion analysis emphasized that the sample of PLA70PGS30H5 showed reasonable behavior against other samples. Also, Alizarin red exhibited that PGSU had a practical effect on different and standard culture mediums on the creation of calcination zones. Real-time PCR analysis was carried out on selected samples, and osteocalcin and osteopontin gens expressions showed that the presence of PGSU into PLA increases gene expression, and the addition of n-HA showed more intensity to the expression of the gens.