Novel injectable and wet bonding bone adhesive: physicochemical characterization and biocompatibility evaluation

BACKGROUND: Bone defect repair is the common clinical dilemmas in surgery, whereas conventional repair materials are limited by poor wet bonding performance, inadequate biocompatibility or the need for secondary surgical removal. To address the above clinical challenges and material defects, this study developed a novel injectable bone adhesive suitable for wet conditions. METHODS: A novel injectable wet-bonding bone adhesive (Bone Glue) was fabricated with bioactive glass, tetracalcium phosphate (TTCP), polyglycolic acid (PGA) fibers, phosphoserine (PS) and phosphate solution as raw materials. Its physicochemical properties were characterized, and in vitro cytotoxicity on L-929 cells was assessed by Methyl thiazolyl tetrazolium (MTT) assay; 12-week subchronic systemic toxicity test in SD rats was performed to evaluate in vivo biosafety. RESULTS: The Bone glue was injectable. Curing triggered structural cross-linking of Bone Glue, with its adhesive strength to titanium increasing from 0.91 ± 0.14 MPa (initial curing) to 1.26 ± 0.09 MPa (complete curing, P < 0.05). The extract maintained a near-physiological pH (7.30-7.35) for 72 h, and all concentrations exhibited > 70% L-929 cell viability. In vivo, no abnormal symptoms, pathological lesions or significant body weight differences were observed in the Bone Glue group, with minor hematological/biochemical variations within normal ranges. CONCLUSIONS: Bone glue possesses favorable physicochemical properties and excellent in vitro/in vivo biocompatibility, which makes it a promising biomaterial for dental implant fixation and bone defect repair in minimally invasive clinical applications.