Novel Epigenetic Modulation Chitosan-Based Scaffold as a Promising Bone Regenerative Material

Abstract

Bone tissue engineering is a complicated field requiring concerted participation of cells, scaffolds, and osteoactive molecules to replace damaged bone. This study synthesized a chitosan-based (CS) scaffold incorporated with trichostatin A (TSA), an epigenetic modifier molecule, to achieve promising bone regeneration potential. The scaffolds with various biphasic calcium phosphate (BCP) proportions: 0%, 10%, 20%, and 40% were fabricated. The addition of BCP improved the scaffolds’ mechanical properties and delayed the degradation rate, whereas 20% BCP scaffold matched the appropriate scaffold requirements. The proper concentration of TSA was also validated. Our developed scaffold released TSA and sustained them for up to three days. The scaffold with 800 nM of TSA showed excellent biocompatibility and induced robust osteoblast-related gene expression in the primary human periodontal ligament cells (hPDLCs). To evaluate in vivo bone regeneration potential, the scaffolds were implanted in the mice calvarial defect model. The excellent bone regeneration ability was further demonstrated in the micro-CT and histology sections compared to both negative control and commercial bone graft product. New bone formed in the CS/BCP/TSA group revealed a trabeculae-liked characteristic of the mature bone as early as six weeks. The CS/BCP/TSA scaffold is an up-and-coming candidate for the bone tissue engineering scaffold.

Effect of Storage Time and Temperature on the Bioactivity of a Chitosan-Derived Epigenetic Modulation Scaffold

“…These observations align with the mechanical properties of the CS/BCP/TSA scaffold, as described by our previous studies [ 18 , 33 ]. Interestingly, all storage conditions, including freezing at −18 °C, chilling at 4 °C, and room temperature at 25 °C, did not affect the scaffolds’ mechanical properties, even if stored for up to 28 days.…”

“…Prior work has demonstrated the CS/BCP/TSA scaffold is an up-and-coming candidate for bone substitution material owing to its osteoinductive ability. This epigenetic modulation scaffold has advantageous characteristics, including (a) excellent biocompatibility with human cells, (b) induced robust osteoblast-related gene expression, and (c) excellent bone regeneration ability in a mouse calvarial defect model [ 18 ]. The details of chitosan-derived epigenetic modulation scaffold in comparison to other commercially available growth factor-enhanced bone grafts are shown in Table 1 , adapted with permission from [ 19 ], 2021, Marco Govoni.…”

“…Our recent study developed a chitosan-based scaffold incorporated with TSA, and this epigenetic modulation scaffold exhibited favorable TSA released for up to 3 days [ 18 ]. Despite its excellent in vitro and in vivo bone regeneration ability, using TSA as an osteogenic molecule has significant challenges in terms of drug stability.…”

“…Based on our previous reports, porous CS/BCP/TSA scaffolds were prepared via a freeze-drying technique [ 18 , 33 , 40 ]. Chitosan powder with ≥90% deacetylation, Mw: 250 kDa, Particle size: 0.5 mm, was obtained from Marine BioResources, Thailand.…”

“…The scaffold with 800 nM of TSA could increase RUNX2 activity in the primary human periodontal ligament cells (hPDLCs). This composite scaffold demonstrated remarkable biocompatibility and induced robust bone formation in the critical mouse calvarial defect [ 18 ]. Besides excellent physiological and biological properties, the stability of the biomaterial over time is an essential factor for its clinical application.…”