Self-healing Poly(methyl methacrylate) Bone Cement Utilizing Embedded Microencapsulated 2-Octyl Cyanoacrylate Tissue Adhesive

Abstract

Extending the functional lifetime of acrylic poly(methyl methacrylate) (PMMA) bone cement may reduce the number of revision total joint replacement (TJR) surgeries performed each year. We developed a system utilizing an encapsulated water-reactive, FDA-approved tissue adhesive, 2-octyl cyanoacrylate (OCA), as a healing agent to repair microcracks within a bone cement matrix. The proposed research tested the following hypotheses: (1) reactive OCA can be successfully encapsulated and the resulting capsules thoroughly characterized; (2) the static mechanical properties of the PMMA composite can be improved or maintained through inclusion of an optimal wt% of OCA-containing capsules; (3) PMMA containing encapsulated OCA has a prolonged lifetime when compared with a capsule-free PMMA control as measured by the number of cycles to failure; and (4) the addition of capsules to the PMMA does not significantly alter the biocompatibility of the material. Based on the experiments reported herein, the primary conclusions of this dissertation are as follows: (1) functional OCA can be encapsulated within polyurethane spheres and successfully incorporated into PMMA bone cement; (2) lower wt% of capsules maintained the tensile, compressive, fracture toughness, and bending properties of the PMMA; (3) inclusion of 5 wt% of OCA-containing capsules in the matrix increased the number of cycles to failure when compared to unfilled specimens and those filled with OCA-free capsules; and (4) MG63 human osteosarcoma cell proliferation and viability were unchanged following exposure to OCA-containing PMMA when compared with a capsule-free control.