Extended fatigue life of a catalyst free self‐healing acrylic bone cement using microencapsulated 2‐octyl cyanoacrylate

Abstract

The tissue adhesive 2-octyl cyanoacrylate (OCA) was encapsulated in polyurethane microshells and incorporated into bone cement to form a catalyst free, self-healing bone cement comprised of all clinically approved components. The bending strength, modulus, and fatigue lifetime were investigated in accordance with ASTM and ISO standards for the testing of PMMA bone cement. The bending strength of bone cement specimens decreased with increasing wt% capsules content for capsules without or with OCA, with specimens of < 5 wt% capsule content showing minimal effect. In contrast, bone cement bending modulus was insensitive to capsule content. Load controlled fatigue testing was performed in air at room temperature on capsule free bone cement (0 wt%), bone cement with 5 wt% OCA-free capsules (5 wt% No OCA), and 5 wt% OCA-containing capsules (5 wt% OCA). Specimens were tested at a frequency of 5 Hz at maximum stresses of 90%, 80%, 70% and 50% of each specimen's bending strength until failure. The 5 wt% OCA exhibited significant self-healing at 70% and 50% of its reference strength (p < 0.05). Fatigue testing of all three specimen types in air at 22 MPa (50% of reference strength of the 5 wt% OCA specimens) showed that the cycles to failure of OCA-containing specimens was increased by two-fold compared to the OCA-free and capsule-free specimens. This study represents the first demonstration of dynamic, catalyst-free self-healing in a biomaterial formulation.

Adhesive Materials for Biomedical Applications

“…Incorporation of the 2-octyl cyanoacrylate slowed down progressive crack propagation under loading compared with unreinforced PMMA cement. In subsequent work [24], it was shown that reinforced specimens were able to withstand twice as many repetitive loading cycles before failure compared with unreinforced specimens. Cyanoacrylate films with a broad range of nanostructured architectures were also created [25].…”

Self‐healing biomaterials: The next generation is nano

“…Biocompatibility is essential for self-healing systems used in biomedical applications; if the system is effective in healing a crack but toxic, it is futile in these applications. Self-healing materials formulations proposed for a biomedical application must pass both ASTM and ISO standards for mechanical and biocompatibility characterization of the materials (Brochu, Matthys, Craig, & Reichert, 2015). Standard protocols are yet to be established for the quantification of the self-healing capacity of biomaterials (Diba et al, 2018).…”

“…In this approach, the self‐healing polymerization does not rely on chemical reactions or external stimuli, and the capsules can be added as an independent component of the bone cement formulation. Brochu et al (2015) also fabricated a capsule‐based self‐healing system using only materials that are currently in clinical use. This system encapsulated the water reactive healing agent, 2‐octul‐cyanoacrylate (OCA) tissue adhesive, in PU microcapsules.…”

Determination of strength and debonding energy of a glass-concrete interface for encapsulation-based self-healing concrete

“…[1][2][3][4][5][6][7][8][9][10]. The working principle of this autonomic healing strategy depends upon an adequate release of the capsule content whenever the matrix is internally damaged.…”