Material properties and progress in modification of hydrogel-based self-expandable poly(methyl methacrylate) bone...

Although traditional poly(methyl methacrylate) (PMMA) bone cements have been widely used in clinical practice, they are beset with many inherent drawbacks such as high polymerization heat, weak osteoinductive and osteoconductive ability, low bioactivity, volumetric shrinkage upon solidification, etc., which significantly limit its clinical application prospects. Chemical or physical modification of PMMA matrix to regulate its material properties has become a research hotspot in the field of bone tissue repair. Self-expandable PMMA bone cement (SBC) is a novel bone cement developed by copolymerizing PMMA matrix with hydrophilic monomers such as acrylic acid, hydroxyethyl acrylate, etc. They are of high bioactivity and adjustable mechanical properties, along with excellent volumetric swelling capability due to the spontaneous water absorption in body fluids. Moreover, with the addition of appropriate antibiotics and fillers, SBC can effectively prevent/heal tissue infection around the implant, and exhibit versatile biomechanical properties required for in vivo implantation, making SBC one of the best alternatives to replace commercially available bone cements. In this paper, the material properties and progress in modification of SBC will be reviewed, the influence of functional monomers and fillers on the biomechanical properties of SBC will be discussed, and the future research direction of SBC will be proposed.