Factors That Determine the Adhesive Strength in a Bioinspired Bone Tissue Adhesive

• Published in: ChemEngineering 2020-03, Vol.4 (1), p.19
• Main Authors: Pujari-Palmer, Michael, Giro, Roger, Procter, Philip, Bojan, Alicja, Insley, Gerard, Engqvist, Hakan
• Format: Article
• Language: English
• Subjects: Adhesion; Adhesion tests; Adhesive bonding; Adhesive strength; Aluminum; Bioadhesives; Biomaterial; Biomaterials Science; Biomaterialvetenskap; Biomedical adhesives for clinical applications; Biomedical materials; Bond strength; Bonding strength; Bone adhesive; Bones; Cements; Chemical engineering; Chemical properties; Composition; Computational fluid dynamics; Continuity (mathematics); Curing; Failure analysis; Failure modes; Fixation; Fractures; Hydroxyapatite; inorganic combinations; Investigations; Laboratories; Linear regression; Metal surfaces; organic; Organic/inorganic combinations; Particle size; Phosphoserine calcium phosphate; Regression analysis; Regression models; Regulatory approval; Shear strength; Shear tests; Stress concentration; Surface layers; Surface roughness; Surgeons; Testing; Tissue adhesive; Underwater adhesives; Unevenness
• ISSN: 2305-7084; 2305-7084
• DOI: 10.3390/chemengineering4010019

Phosphoserine-modified cements (PMCs) are a family of wet-field tissue adhesives that bond strongly to bone and biomaterials. The present study evaluated variations in the adhesive strength using a scatter plot, failure mode, and a regression analysis of eleven factors. All single-factor, continuous-variable correlations were poor (R2 < 0.25). The linear regression model explained 31.6% of variation in adhesive strength (R2 = 0.316 p < 0.001), with bond thickness predicting an 8.5% reduction in strength per 100 μm increase. Interestingly, PMC adhesive strength was insensitive to surface roughness (Sa 1.27–2.17 μm) and the unevenness (skew) of the adhesive bond (p > 0.167, 0.171, ANOVA). Bone glued in conditions mimicking the operating theatre (e.g., the rapid fixation and minimal fixation force in fluids) produced comparable adhesive strength in laboratory conditions (2.44 vs. 1.96 MPa, p > 0.986). The failure mode correlated strongly with the adhesive strength; low strength PMCs (2 MPa) PMCs failed adhesively. Failure occurred at the interface between the amorphous surface layer and the PMC bulk. PMC bonding is sufficient for clinical application, allowing for a wide tolerance in performance conditions while maintaining a minimal bond strength of 1.5–2 MPa to cortical bone and metal surfaces.