Biological activity of hydroxyapatite/poly(methylmethacrylate) bone cement with different surface morphologies and modifications for induced osteogenesis

Abstract

Although having advantages such as good mechanical property and rapid curing, the poor absorption and biological activity of hydroxyapatite (HA)/poly(methylmethacrylate) (PMMA) bone cement limits its clinical application. Therefore, it is of vital importance to improve the integration and the biological activity of HA/PMMA bone cement. In this study, spherical and rod-like HA/PMMA bone cement with different content of P(MMA-co-MPS) were chosen to enhance its interface bioactivity. The content of P(MMA-co-MPS) on the surface of HA was 12, 30, 15, and 28%, respectively, corresponding to 0.3 r-HA, 1.5 r-HA, 0.3 s-HA, and 1.5 s-HA, whose calcium-to-phosphorus (Ca/P) ratios were 1.62, 1.5, 1.65, and 1.53, respectively, and were confirmed by energy dispersive spectroscopy. From scanning electron microscope, we found that the spherical HA (s-HA) promotes the biomineralization on the surface of PMMA than rod-like HA (r-HA). In addition, cell experiments in vitro showed that s-HA/PMMA with lower modification degree (0.3) of P(MMA-co-MPS) results in more cell adhesion and more evenly distributed on surface spreading while observed under laser confocal microscope. Meanwhile, in vitro, cell proliferation and alkaline phosphatase activity indicated that s-HA/PMMA bone cement promotes early osteogenic differentiation of rBMSCs in a deeper extent than r-HA/PMMA, demonstrating that 0.3 s-HA/PMMA provides a favorable theoretical basis for the further clinical application of HA/PMMA bone cement as an optimized bone repair material.

Osteogenic stimulation of human dental pulp stem cells with self‐setting biphasic calcium phosphate cement

“…To observe the surface of the cement after the hydration reaction, we examined the morphology of the hydrated crystals and the interlock between the crystals using a field emission scanning electron microscope (Hitachi SU8000, Japan) (Che, Min, Wang, Rao, & Quan, ; Kim et al, ). A 200‐Å‐thick gold film layer was deposited on the surface of the CPC sample prior to SEM analysis.…”

PMMA Bone Cements Modified with Silane-Treated and PMMA-Grafted Hydroxyapatite Nanocrystals: Preparation and Characterization

“…Therefore, the appearances of the ν(CH) and ν(CH 2 ) groups at 2928 and 2848 cm −1 , respectively, the ν(C=C) at 1607 and the ν(Si-C) at 762 cm −1 (Figure 1b) indicate that the hydrolyzed VTMS silane was successfully grafted onto the surfaces of the HAP particles as per the scheme of proposed reactions in Figure 2a,b [32]. Figure 1c is the spectrum of the gHAP, which clearly shows the specific absorption bands of the PMMA grafted onto surfaces of the HAP particles, such as δ(C=O) at 1729 and 754 cm −1 , δ(CH 2 ) at 1452 cm −1 , ν(-CH 3 , OCH 3 and CH 2 ) vibrations at 2997, 2953 and 2854 cm −1 , δ(CH 3 ) at 1453 cm −1 and ester C-O-C bands at 1243 and 1143 cm −1 [33,34]. The PMMA grafting reaction is displayed in Figure 2c.…”

Biomimetically precipitated nanocrystalline hydroxyapatite

“…In tissue engineering, researchers embedded nano-HAP particles into a 3D scaffold combined with stem cells creating a favorable osteogenic microenvironment [57]. An in vitro experiment demonstrated the early biological response of stem cells on bone cement conducted by Che and co-workers [60]. It has shown the addition of the nano-HAP phase into PMMA-based bone cement improved cell adhesion, spreading, proliferation, and early osteogenesis.…”