HEMA‐Modified Expandable P(MMA‐AA) Bone Cement with Dual Water Absorption Networks

Abstract

Although the shrinkage of polymethyl methacrylate (PMMA) bone cement has been tackled by the poly(methyl methacrylate‐co‐acrylic acid) [P(MMA‐AA)] bone cement due to the expandable P(MMA‐AA) copolymer in the solid phase, the hydrophobicity of PMMA and its solidification restrict simulated body fluid (SBF) diffusion and expansion properties. In this research, hydroxyethyl methacrylate (HEMA)‐modified P(MMA‐AA) bone cement (HMBC) is obtained by introducing HEMA into the liquid phase of P(MMA‐AA) bone cement. It is assumed that the dual water absorption networks can promote the SBF absorption capacity, thus resulting in the increased expansion behavior. The results demonstrate that the introduction of HEMA improves the hydrophilicity of the bulk. SBF absorption efficiency and swelling efficiency are promoted in the primary step of expansion. The porous structure of HMBC contributes to the increased SBF absorption and swelling in the second step of expansion behavior. Meanwhile, the remarkable absorption ratio and expansion ratio reach 88.5% and 97.4%, respectively. Furthermore, enhanced biocompatibility and osteogenesis activity provide HMBC as a promising biomaterial in the clinical setting.

Swelling behavior of expandable poly(methyl methacrylate‐acrylic acid)/polymethyl methacrylate bio‐composites with different crosslinking densities

“…Although the setting time of all components, except for EBC 1, was longer than the value specified in ISO 5833, the prolonged setting time enabled the flexible operation time in the surgeries, meanwhile, it was also possible for the increment of the SBF absorption and swelling behavior of the EBC as the adequate exposure time with the SBF before the solidification, which was conducive to the diffusion of SBF into EBC and subsequently the full stretch of the three-dimensional network structure in the P(MMA-AA) copolymer without the restriction of rigid PMMA skeleton. [8,18]…”

High water‐absorbent and fast‐expanding PMMA bone cement with double‐bridged structure

“…absorption and swelling behavior tends to reach an equilibrium with the solidification of the bone cement. 11,12 (b) The absorption and expansion capacity of the composite depends entirely on the content and distribution of the internal additives. [11][12][13] In the case of low additive amount, it will be blocked or even embedded by hydrophobic PMMA particles, which cannot transfer water effectively and thus has an inferior water absorption and expansion capacity.…”

“…11,12 (b) The absorption and expansion capacity of the composite depends entirely on the content and distribution of the internal additives. [11][12][13] In the case of low additive amount, it will be blocked or even embedded by hydrophobic PMMA particles, which cannot transfer water effectively and thus has an inferior water absorption and expansion capacity. With the increased amount of additives, although the composite bone cement has excellent water absorption and swelling properties as a higher contact probability, the prolonged solidification time and reduced mechanical properties of bone cement affect its long-term stability in the human body.…”

“…The promoted ability of its threedimensional network structure to contact with water per unit of time accelerated the absorption, resulting in a rapid expansion of the composite bone cement. 11,12 Taking advantage of the large surface area of twodimensional sheet-like graphene oxide (GO) and its excellent performance of hydrophilic and mechanical properties, [14][15][16][17][18] poly(methyl methacrylate-acrylic acid)graphene oxide [P(MMA-AA)-GO] was prepared by in situ polymerization, a bridging structure was constructed between the P(MMA-AA) microspheres by layered graphene oxide flakes, which shortened the water transfer routes between the P(MMA-AA) microspheres for the rapid transfer rate of water. Meanwhile, hydroxyethyl methacrylate (HEMA) had been widely used in pharmaceutical and medical applications due to its biocompatibility, non-toxicity, high permeability to small metabolites, high hydrophilicity, and resistance to adhesion of blood proteins and cells.…”

“…The bridging structure with hydrophilic groups was also formed between the originally hydrophobic PMMA particles as well as additives with the water absorption and swelling capacity, which cannot interact with each other, thus forming a threedimensional water transfer network. Although there were many reports on GO and HEMA modified bone cements, [24][25][26]12 these works mainly focused on the single solid phase modification or liquid phase modification. GO modified bone cement was mainly designed to improve the mechanical properties.…”