Biofunctional phosphorylated magnetic scaffold for bone tissue engineering

The development of highly bioactive engineered scaffolds is required to promote bone regeneration and the success of bone tissue engineering treatment approaches. This study attempts to fabricate a biofunctional magnetic scaffold based on new phosphorylated polycaprolactone combined with gelatin (MNPs-PCL-P/gelatin). Phosphorylated polymer and magnetic nanoparticles (MNPs) were synthesized and characterized by NMR, FT-IR, TEM, and DLS instruments. The synthetic polymer, MNPs, and biopolymer were mixed then freeze-dried to prepare a porous scaffold. Physiochemical assessments showed that a scaffold with well-developed porous morphology, and stable structure was obtained. MNPs-PCL-P/gelatin scaffold had no toxicity on human dental pulp stem cells (hDPSCs). The use of phosphorous-containing polymer resulted in improvement of the scaffold's osteoconductivity to support proper cell attachment and promote cell proliferation. Phosphate group by mimicking function of bone phosphate groups stimulate bone mineralization that reflected by alizarin red S staining assay. The presence of MNPs resulted in higher ALP activity and increased expression level of RUNX2, BMP2 osteogenic biomarkers. Also, phosphorylation enhanced osteoinductivity of scaffold and upregulate RUNX2, BMP2, COL1A1, and OCN genes in phosphors-containing scaffold test groups. It seems that biocompatible MNPs-PCL-P/gelatin scaffold possesses the potential of applications in bone tissue engineering.