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.