Biomechanical and cellular assessment of novel partially demineralized allogeneic bone plates: an ex-vivo and in-vitro study

Abstract

Purpose This study aimed to compare commercial allogeneic cortical bone plates (cCP) with innovative, differently demineralized CP (dCP) in biomechanics and human osteoblast (HOB) viability ex-vivo and in-vitro. Methods Breaking strength (BS; in N) and flexibility (F; in mm) of cCP and dCP were assessed and compared using four groups ((1) non-hydrated, (2) hydrated for 10, (3) 30, and (4) 60 min in saline), respectively. Cell viability of HOB was evaluated by resazurin reduction on non-hydrated cCP and dCP after 3, 7, and 10 days. Scanning electron microscopy (SEM) visualized CP breaking edges, internal structures, HOB cell morphology, and growth patterns. Results BS of hydrated dCP (d10: 15.45 ± 7.01 N, d30: 19.40 ± 3.78 N, d60: 20.31 ± 4.90 N) was significantly lower than that of non-hydrated dCP (d0: 74.70 ± 29.48 N) and native and hydrated cCP (c0: 75.00 ± 19.27 N, c10: 83.73 ± 10.92 N, c30: 83.80 ± 22.63 N, c60: 75.58 ± 14.25 N, p < 0.001 each). Next, dCP groups (d0: 2.64 ± 0.78 mm, d10: 2.14 ± 1.15 mm, d30: 2.76 ± 3.78 mm, d60: 2.86 ± 0.89 mm) exhibited significantly higher F than cCP groups (c0: 0.49 ± 0.14 mm, c10: 0.66 ± 0.10 mm, c30: 0.67 ± 0.16 mm, c60: 0.59 ± 0.12 mm, p < 0.05 each). No significant differences in F were observed among the different dCP groups. HOB cell viability was significantly increased on cCP compared to dCP after 7 (97.64 ± 2.11% vs. 76.88 ± 4.82%) and 10 days (96.14 ± 4.13% vs. 76.45 ± 4.64%; p < 0.001 each). SEM revealed well-defined breaking edges in cCP, whereas dCP displayed tear-off edges with shearing extensions. SEM showed disordered growth patterns and a physiological HOB cell morphology on dCP, contrasting with a parallel growth of fibroblast-like-looking HOB on cCP. Conclusions Compared to cCP, dCP showed increased flexibility but lower breaking strength and reduced HOB vitality. The increased flexibility and a decrease in breaking strength are likely due to differences in elasticity between dCP and cCP. The use of dCP may improve clinical handling efficiency.