Loading of VEGF and BMP2 to PNIPAAm-based hydrogel as a scaffold for bone regeneration

Several techniques have been developed to create 3D biomimetic scaffolds based on hydrogels, and these have recently become popular in tissue engineering. Given that the incorporation of osteogenic reagents such as VEGF and BMP2 improves bone regeneration, in this study, we evaluated a PCL-P (HEMA-NIPAAm) hydrogel consisting of polycaprolactone (PCL) blocks and poly(N-isopropylacrylamide-hydroxyethylmethacrylate) (NIPAAm-HEMA) acrylate blocks for the delivery of two growth factors, VEGF and BMP2, simultaneously. Physical characterization of PCL-P (HEMA-NIPAAm) hydrogel was evaluated by FTIR, SEM, and 1H-NMR. VEGF and BMP2 were loaded on the hydrogel and the release of both growth factors (GFs), cytotoxicity assay, and Alizarin red S staining the human dental pulp stem cells (hDPSCs) were evaluated. The initial release occurred rapidly within the first 24 hours, with 45% and 50% of both growth factors (GFs) being released. By the end of the study period, a total of 80% of BMP2 and 85% of VEGF had been released from the hydrogel scaffold.Top of Form The cell viability of samples was measured at 91%, 205%, and 470% after 24 h and on the third and fifth day, respectively. In the SEM images, hDPSCs fully adhere, colonize, and proliferate on the hybrid copolymer, which is non-toxic to cells. The produced hydrogel demonstrated no evident cytotoxicity in hDPSCs cell lines and our novel PCL-P-based hydrogel scaffold contained growth factors as a matrix for hDPSCs and cell seeding, which could be a beneficial technique used in 3D constructs with high potential for bone tissue engineering and regenerative medicine.