Fabrication and characterization of bifunctional PCL/chitosan scaffolds decorated with MXene nanoflakes for bone tissue engineering

Abstract

The implantation of bioresorbable compositions has emerged as a promising therapeutic strategy to treat damaged bone tissues. To develop versatile bone scaffolds, polycaprolactone (PCL) is known as a dominant polymeric material regarding its unique biocompatibility and biodegradability. However, using PCL in a single structure reveals insufficient mechanical properties, in tandem with poor biological activity. To modulate these features, the combination of PCL and chitosan has been broadly proposed due to the proper bioactivity behavior of the chitosan component. It is also declared that the presence of MXene elements in the bone scaffolds could enhance the osteogenic impact and modify the mechanical behavior to match the surrounding bone tissue. To explore the synergetic effect of chitosan and MXene in enhancing the features of PCL structure, the PCL/chitosan/MXene ternary system was designed in this study. Accordingly, MXene nanosheets were synthesized and incorporated with various filler contents of 1, 3, and 5 % into PCL/chitosan to boost the overall characteristics. The obtained data exhibited a rise in porosity ratio from 22 to 30 % and a decrease in contact angle from 95.45 to 79.86⁰ by embedding MXene up to 3 %. Young's modulus was enhanced from 0.4 to 1.2 MPa, corroborating the generation of scaffolds with superior mechanical strength and rigidity. The compositions containing MXene up to 3 % revealed no cytotoxicity and human osteoblast cell assay approved the cell adhesion affinity of the designed architectures. Furthermore, the presence of MXene nanosheets resulted in the promoting of antimicrobial features in the membranes as a bifunctional behavior. Correspondingly, embedding an optimized ratio of MXene nanoparticles into the PCL/chitosan scaffold could create a suitable scaffolding architecture toward the generation of new bone tissues, benefiting appropriate cell attachment, proliferation, and differentiation.