In Vitro and In Vivo Evaluation of Polycaprolactone/Carboxymethyl Chitosan Composite <scp>3D</scp> Scaffolds Loaded With Cerivastatin and <scp>45S5</scp> Bioglass Nanoparticles for Bone Tissue Engineering in Rat Calvarial Defects

Today, tissue engineering and nanotechnology researchers are looking to design a bone scaffold that can mimic bone extracellular matrix and stimulate bone regeneration by regulating cell activity and differentiation. The scaffold must be biocompatible and bioactive and can provide a suitable porous physical structure for the growth and adhesion of cells and then undergo biological degradation. Finding an effective active ingredient with an optimal dose that can increase bone regeneration is also important. In this study, polycaprolactone (PCL)/carboxymethyl chitosan (CMC)-bioglass nanoparticles (BGNP) scaffolds incorporating varying concentrations of cerivastatin (Ceriv) were fabricated and subjected to comprehensive in vivo and in vitro characterization to assess their impact on bone healing. Scaffolds with varying cerivastatin concentrations (0.01, 0.1, and 1 wt%) were fabricated via freeze-casting and subsequently examined using scanning electron microscopy (SEM). In vitro evaluations included tests of the material's physical properties, cytotoxicity, blood compatibility, pH levels, blood coagulation index, release profile, and Alizarin staining. In vivo evaluations involved the implantation of scaffolds into rat calvarial defects distributed across six groups, each comprising six subjects, over a period of 12 weeks. Histological analysis utilizing hematoxylin-eosin and trichrome-Mason staining assessed the formation of bone and fibrous tissue, along with the quantities of osteons, osteoblasts, and fibroblasts. In vitro studies demonstrated that the scaffold was biocompatible and exhibited optimal physical properties. Histological analysis revealed a significant increase in bone formation and osteon quantity with 0.1% cerivastatin (p < 0.05). Higher amounts of cerivastatin (1%) led to less bone formation and more fibrous tissue. This increase was linked to a higher blood coagulation index and acidity caused by scaffold degradation (p < 0.05). In summary, all scaffolds, except those with 1 wt% cerivastatin, promoted bone regeneration. The PCL/CMC-BGNP-Ceriv 0.1% concentration produced the best results, which means it works well to help bones heal.