Estimating Osteogenic Potential of Rose Hip Seed Functionalised Hydroxyapatite Nanoparticles as a Bone Graft Substitute: An In-vitro Study

Introduction: Green synthesis is an environmentally friendly, non toxic method for formulating Hydroxyapatite Nanoparticles (HApNPs) and functionalising them using plant derivatives, such as Rose hip Seed extracts (Rh). Rose hip seeds have demonstrated osteogenic properties, making them ideal for synthesising a nanoparticle bone graft substitute capable of inducing bone formation. Aim: To evaluate the osteogenic potential of Rose hip seed functionalised HApNPs. Materials and Methods: The present study was an in-vitro investigation conducted in the Department of Orthodontics, Meenakshi Ammal Dental College and Hospital, Meenakshi Academy of Higher Education and Research (Deemed to be University), Chennai, Tamil Nadu, India from December 2022 to December 2024. synthesis of Rose hip Seed Extract-functionalised HApNPs (RhHApNPs) was carried out. The nanoparticles were subjected to physical characterisation, including HApNPs Field Emission Scanning Electron Microscopy (FESEM) analysis Energy-dispersive X-ray (EDX) analysis X-ray Diffraction (XRD) analysis Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) analysis. Biological characterisation involved a haemolytic test, while chemical characterisation included the Calcium Mineralisation Assay, Alkaline Phosphatase (ALP) activity test, and collagen estimation test. The outcomes of these tests were represented graphically using Origin software. Results: The FESEM analysis revealed elongated, hexagonal, and spherical-shaped RhHApNPs, with a particle size range of 10-50 nm. EDX analysis demonstrated characteristic elemental peaks for Ca, P, O, and C in RhHApNPs. The XRD test indicated 55.6% crystallinity. ATR-FTIR analysis identified peaks of PO4³- , along with the presence of other functional groups. The blood compatibility test results showed that the rate of haemolysis was below 5%, indicating good blood compatibility. RhHApNPs exhibited greater mineralisation density compared to non RhHApNPs, evidenced by higher Optical Density (OD). The ALP Activity test showed increased levels of ALP expression in RhHApNPs compared to non functionalised counterparts. The collagen estimation assay revealed collagen formation over NIH 3T3 cell line culture. Conclusion: The newly synthesised RhHApNPs were elongated, hexagonal, and spherical, with a size range of 10-50 nm, demonstrating a Ca/P weight % of 1.99 and a crystallinity of 55.6%. The RhHApNPs also exhibited good haemocompatibility and increased osteogenic activity when compared to non functionalised HApNPs.