Immunological Evaluation of PLLA/GO Scaffolds in Goat Mandibular Bone Regeneration

Abstract

Bone repair remains a significant challenge in orthopedics and reconstructive surgery, especially in complex fractures and large tissue defects. Biomaterials such as graphene oxide (GO) and poly-L-lactic acid (PLLA) are promising due to their physicochemical properties and biocompatibility. However, the immune response plays a critical role in graft success. In this study, PLLA/GO scaffolds are implanted in the right antimeres of nine goat mandibles, while the left antimeres are stabilized with titanium plates and serve as controls. Samples are collected at 15-, 45-, and 60-days post- implantation and examined using histology and immunohistochemistry to assess inflammation, bone organization, and bone-implant integration. At 15 days, hematoxylin and eosin staining show early inflammatory reactions at the PLLA/GO interface, whereas control samples display regular histological patterns. At 45 days, denser and more compact bone tissue indicate progressive structural organization. By 60 days, the samples present advanced bone maturation and active osteogenesis. Steven's Blue staining confirms mineral deposition, and osteoblast-like cells deposit new matrix at the scaffold-tissue interface. Immunohistochemical detection of osteocalcin and VEGF reveals osteoblastic activity and angiogenesis. These results demonstrate that PLLA/GO scaffolds promote bone regeneration and integration, supporting their potential for clinical application in mandibular repair.