Nanofunctionalized zirconia and barium sulfate particles as bone cement additives

Figures & data

Figure 1 SE M images of bone cements used in cytocompatibility testing [Left: 15K X (scale bar = 1 μm), Right: 50K X (scale bar = 100 nm)]: Plain (A, B), ZM (containing micron particulate ZrO₂) (C, D), ZN (containing unfunctionalized ZrO₂ nano-particles) (E, F), ZNFT (containing functionalized ZrO₂ nano-particles) (G, H), BM (containing micron particulate BaSO₄) (I, J), BN (containing unfunctionalized BaSO₄ nano-particles) (K, L), and BNFT (containing functionalized BaSO₄ nano-particles) (M, N).

Figure 2 Osteoblast cell density, after 4 hours, as a function of bone cement type. Data = mean +/− SEM; N = 3. Plain = Unmodified bone cements; BM = Bone cements with micron particulate BaSO₄, BN = Bone cements with unfunctionalized BaSO₄ nanoparticles, BNFT = Bone cements with functionalized BaSO₄ nanoparticles; ZM = Bone cements with micron particulate ZrO₂, ZN = Bone cements with unfunctionalized ZrO₂ nanoparticles; ZNFT = Bone cements with functionalized ZrO₂ nanoparticles. *Compared to plain bone cement; adhesion on bone cements containing the following ceramic particles was found to be greater: micron particulate BaSO₄ (p < 0.05), unfunctionalized BaSO₄ nano-particles (p < 0.05), and BaSO₄ nano-particles functionalized with TMS (p < 0.005).

Figure 3 Osteoblast cell-density, after 24 hours, as a function of bone cement type. Data = mean +/− SEM; N = 3. Plain = Unmodified bone cements, BM = Bone cements with micron particulate BaSO₄, BN = Bone cements with unfunctionalized BaSO₄ nanoparticles, BNFT = Bone cements with functionalized BaSO₄ nanoparticles, ZM = Bone cements with micron particulate ZrO₂, ZN = Bone cements with unfunctionalized ZrO₂ nanoparticles, ZNFT = Bone cements with functionalized ZrO₂ nanoparticles. *Compared to plain bone cement, adhesion on bone cements containing all ceramic particles was found to be greater: micron particulate BaSO₄ (p < 0.1), unfunctionalized BaSO₄ nano-particles (p < 0.005), ZrO₂ nano-particles functionalized with TMS (p < 0.005), BaSO₄ nano-particles functionalized with TMS (p < 0.001), micron ZrO₂ particles (p < 0.001), and unfunctionalized ZrO₂ nano-particles (p < 0.001). ^ΨCompared to bone cements containing micron BaSO₄ particles, adhesion was found to be greater on bone cements containing BaSO₄ nano-particles functionalized with TMS (p < 0.05). ^€WRT bone cements containing micron ZrO₂ particles, adhesion was found to be greater on bone cements containing unfunctionalized ZrO₂ nano-particles (p < 0.05) and ZrO₂ nano-particles functionalized with TMS (p < 0.1).

Figure 4 Fluorescence microscopy images (magnification = 10X) of osteoblasts after 4 hours of adhesion on different bone cements: A) Plain, B) ZM (containing micron particulate ZrO₂), C) ZN (containing unfunctionalized ZrO₂ nano-particles), D) ZNFT (containing ZrO₂ nano-particles functionalized with TMS, E) BM (containing micron particulate BaSO₄), F) BN (containing unfunctionalized BaSO₄ nano-additives), and G) BNFT (containing BaSO₄ nano-additives functionalized with TMS).

Figure 5 Fluorescence microscopy images (magnification = 10X) of osteoblasts after 24 hours of proliferation on different bone cements: A) Plain, B) ZM (containing micron particulate ZrO₂), C) ZN (containing unfunctionalized ZrO₂ nano-particles), D) ZNFT (containing ZrO₂ nano-particles functionalized with TMS, E) BM (containing micron particulate BaSO₄), F) BN (containing unfunctionalized BaSO₄ nano-additives), and G) BNFT (containing BaSO₄ nano-additives functionalized with TMS).

Figure 6 Representative tensile stress-strain curves for various bone cements. One representative of three trials is shown for each bone cement. Bone cements tested included: Plain, ZM (containing micron particulate ZrO₂), ZN (containing unfunctionalized ZrO₂ nano-particles), ZNFT (containing functionalized ZrO₂ nano-particles), BM (containing micron particulate BaSO₄), BN (containing unfunctionalized BaSO₄ nano-particles), and BNFT (containing functionalized BaSO₄ nano-particles). A) All bone cements, B) Bone cements containing ZrO₂ particles, and C) Bone cements containing BaSO₄ particles.

Figure 7 Representative compressive stress-strain curves for various bone cements. One representative of three trials is shown for each bone cement. Bone cements tested included: Plain, ZM (containing micron particulate ZrO₂), ZN (containing unfunctionalized ZrO₂ nano-particles), ZNFT (containing functionalized ZrO₂ nano-particles), BM (containing micron particulate BaSO₄), BN (containing unfunctionalized BaSO₄ nano-particles), and BNFT (containing functionalized BaSO₄ nano-particles). A) All bone cements, B) Bone cements containing ZrO₂ particles, and C) Bone cements containing BaSO₄ particles.

Table 1 Maximum stresses and Young’s moduli of various bone cements under tension: Plain, ZM (containing micron particulate ZrO₂), ZN (containing unfunctionalized ZrO₂ nano-particles), ZNFT (containing functionalized ZrO₂ nano-particles), BM (containing micron particulate BaSO₄), BN (containing unfunctionalized BaSO₄ nano-particles), and BNFT (containing functionalized BaSO₄ nano-particles). Young’s moduli values for bone obtained from study by Mente et al

Substrate	Maximum stress (N/m^2)	Young’s modulus (N/m^2)
Plain	1.30E + 07	6.74E + 08
ZNFT	9.88E + 06	1.89E + 08
ZN	9.32E + 06	3.16E + 08
ZM	1.28E + 07	2.77E + 08
BNFT	1.16E + 07	2.55E + 08
BN	1.00E + 07	2.38E + 08
BM	1.25E + 07	2.98E + 08
Cortical bone – dry		1.82E + 10
Cortical bone – wet		1.24E + 10
Trabecular bone – dry		7.80E + 09

Figure 8 SE M images of bone cements fractured in tension [Left: 5K X (scale bar = 3 μm), Right: 15K X (scale bar = 1 μm)]: Plain (A, B), ZM (containing micron particulate ZrO₂) (C, D), ZN (containing unfunctionalized ZrO₂ nano-particles) (E, F), ZNFT (containing functionalized ZrO₂ nano-particles) (G, H), BM (containing micron particulate BaSO₄) (I, J), BN (containing unfunctionalized BaSO₄ nano-particles) (K, L), and BNFT (containing functionalized BaSO₄ nano-particles) (M, N).

Table 2 Compressive stress required to obtain 56% strain (1 mm of compression) in various bone cements: Plain, ZM (containing micron particulate ZrO₂), ZN (containing unfunctionalized ZrO₂ nano-particles), ZNFT (containing functionalized ZrO₂ nanoparticles), BM (containing micron particulate BaSO₄), BN (containing unfunctionalized BaSO₄ nano-particles), and BNFT (containing functionalized BaSO₄ nano-particles). Maximum compressive stress at 56% strain for bone calculated from Young’s moduli values obtained from study by Mente et al

Substrate	Maximum compressive stress (N/m^2)
Plain	−3.63E + 07
BN	−2.36E + 07
ZNFT	−2.36E + 07
BNFT	−1.90E + 07
ZN	−1.04E + 07
BM	−9.71E + 06
ZM	−7.50E + 06
Cortical bone – dry	−1.02E + 10
Cortical bone – wet	−6.94E + 09
Trabecular bone – dry	−4.37E + 09

Table 3 Radio-opacity, as indicated by mean gray value, of various bone cements. Higher mean gray value is indicative of a greater degree of radio-opacity. Bone cements analyzed included: Plain, ZM (containing micron particulate ZrO₂), ZN (containing unfunctionalized ZrO₂ nano-particles), ZNFT (containing functionalized ZrO₂ nano-particles), BM (containing micron particulate BaSO₄), BN (containing unfunctionalized BaSO₄ nano-particles), and BNFT (containing functionalized BaSO₄ nano-particles)

Substrate	Mean gray value (Normalized)
Plain	43.68
ZM	76.59
ZN	76.30
ZNFT	72.66
BM	54.63
BN	49.81
BNFT	63.44