Mechanical characterisation of polylactic acid-alendronate bioscrew in different concentrations of glutaraldehyde

Background: Bioscrew is a developing innovation as a substitute to avoid re-surgery for screw removal; one of the bioscrew materials is polylactic acid (PLA). Alendronate plays a role in reducing osteoclastic activity, causing a decrease in osteoclast-mediated bone resorption, thereby accelerating the process of bone union. Objective: This study determines adding various glutaraldehyde concentrations to the bioscrew mechanical characteristics. Method: This study used the PLA bioscrew immersed into bovine hydroxyapatite (BHA)-gelatin (GEL)-alendronate (ALE) solution, then added with 0% (F1), 1% (F2), and 1,5% (F3) glutaraldehyde (GTA) as cross-link agent. Result: The pore diameter for F1, F2, and F3 were: 38.90±15.34; 29.01±8.94; and 30.58±7.40 μm, respectively. The flexural strength for F1, F2, and F3 were: 1.00±0.22, 1.18±0.13, and 1.11±0.16 MPa, respectively. The pull-out strength for F1, F2, and F3 were: 4.88 ± 0.79; 7.87 ± 0.24; and 7.65±1.02 N, respectively. The degradation rate for F1, F2, and F3 were: 14.40±2.08; 3.81±0.67; and 4.97±0.58 %, respectively. This study has found that glutaraldehyde concentrations significantly affect pull-out strength and degradation rate. The highest mechanical strength and slowest degradation rate for % weight loss was F2. Conclusion: Adding glutaraldehyde may enhance the mechanical characteristics of the bioscrew.