Hybrid Nanocomposites of PCL‐ PLA with Graphene and Cellulose Nanocrystal to Prepare Foams for Bone Regeneration

ABSTRACT Three‐dimensional (3D) and open‐porous scaffolds with the capability to induce osteogenesis were of interest to researchers in the field of biomedical engineering. Poly (ε‐caprolactone) was proven to be highly biocompatible, with the capability to induce osteogenesis of human mesenchymal stem cells (hMSCs). However, its high crystallinity and fast crystallization limit its capability to produce a stable porous structure due to pore shrinkage. Its low mechanical strength is another issue, as higher stiffness is a requirement for directing the fate of hMSCs to bone formation. In this regard, PCL was blended with polylactic acid (PLA) with a weight ratio of 60:40 using 1,4‐Dioxane. Salt leaching and freeze‐thaw methods were used to create porous structures. Certain nanoparticles were also found to be osteoinductive, such as graphene and cellulose nanocrystal (CNC). The nanoparticles, with the kinetical and thermodynamical tendency toward PCL, were used to suppress the coalescence of the PLA droplets to form a uniform blend. The rheological and crystallization behavior, as well as the morphology of the blend in both states (film and porous structure) were evaluated. The selected foams were further used as scaffolds for bone regeneration. The scaffolds were highly biocompatible, with the capability to induce osteogenesis.