Preparation and characterization of PCL polymeric scaffolds coated with chitosan/bioactive glass/gelatin nanoparticles using the tips methodology for bone tissue engineering

Objective(s): The present study aimed to prepare polycaprolactone (PCL) scaffolds with high porosity and pore interconnectivity, in order to copy the microstructure of natural bones using the thermally induced phase separation (TIPS) technique. Materials and Methods: The scaffolds were coated with chitosan (CH), bioactive glass (BG), and gelatin nanoparticles (GEL NPs) and assessed using scanning electron microscopy and Fourier-transform infrared spectroscopy (FTIR). The effects of various coatings on the scaffold characterizations, proliferation, and mineralization of MG-63 osteoblast-like cells were evaluated. Results: The size of the prepared BG and GEL NPs was estimated to be 400 and 234 nanometers, respectively. The porosity and contact angle of PCL/CH/GEL NPs/BG was 74% and 72 degrees, respectively. Weight loss and electron microscopy evaluations indicated the improved degradation rate of the scaffolds and spreading tendency of the cells on the scaffolds when modified as compared to the scaffolds that were purely obtained from PCL. In addition, the in-vitro studies revealed that the MG-63 cells cultured on the PCL/CH/GEL NPs/BG scaffolds showed improved cell proliferation more significantly compared to the scaffolds obtained from PCL, PCL/CH/GEL NPs, PCL/CH, and PCL/GEL NPs. Mechanical examinations also showed that PCL/CH/GEL/BG scaffolds had the highest mechanical strength compared to other groups (i.e., 4.66 Mpa). Cell viability was estimated to be 96.7%, and the alizarin red test indicated the significant improvement of mineralization in the PCL/CH/GEL NP group. Conclusion: According to the results, the PCL scaffolds that were modified by CH/GEL NPs/BG had the high potency to be used as bone tissue engineering scaffolds.