Abstract：
Hybrid nanohydroxyapatite/carboxymethyl chitosan (nHAp-CMC) scaffolds have garnered significant attention in the field of regenerative engineering. The current study comparatively analyzed the physicochemical and biological properties of synthetic nanohydroxyapatite (SnHA)- and eggshell-sourced nanohydroxyapatite (EnHA)- based CMC biocomposites for pulp-dentin regeneration. EnHA and CMC were synthesized through a chemical process, whereas SnHA was commercially obtained. Composite scaffolds of SnHA-CMC and EnHA-CMC (1:5 w/w) were prepared using freeze-drying method. All biomaterials were characterized by FTIR, micro-Raman, XRD, HRSEM-EDX, and TEM analyses, and their in vitro bioactivity was assessed by immersing them in simulated body fluid for 21 days. The biological properties of the composite scaffolds were evaluated by assessing cytocompatibility using MTT assay and biomineralization potential by analyzing the odontogenic gene expressions (ALP, DSPP, DMP-1 and VEGF) in human dental pulp stem cells (DPSCs) using RT-qPCR method. Characterization studies revealed that EnHA displayed higher crystallinity and superior surface morphology compared to SnHA. The composite scaffolds showed a highly interconnected porous microstructure with pore sizes ranging between 60 and 220 μm, ideal for cell seeding. All tested materials, SnHA, EnHA, and their respective composites, displayed high cytocompatibility, increased ALP activity and degree of mineralization with significant upregulation of odontogenic-related genes on DPSCs (p < 0.05). Nevertheless, the odontogenic differentiation potential of EnHA-CMC on DPSCs was significantly higher when compared to SnHA-CMC. The findings from this study highlight the potential of EnHA-CMC as a promising candidate for pulp-dentin engineering.
摘要：
混合纳米羟基磷灰石/羧甲基壳聚糖(nHAp-CMC)支架在再生工程领域得到了广泛的关注。当前的研究比较分析了合成纳米羟基磷灰石（SnHA）和蛋壳基纳米羟基磷灰石（EnHA）的CMC生物复合材料的物理化学和生物学特性，用于牙髓牙本质再生。EnHA和CMC是通过化学过程合成的，而SnHA是商业获得的。采用冷冻干燥法制备了SnHA-CMC和EnHA-CMC(1:5w/w)复合支架。所有生物材料均通过FTIR表征，微拉曼，XRD,HRSEM-EDX,和TEM分析，并通过将其浸入SBF中21天来评估其体外生物活性。通过使用MTT测定法评估细胞相容性和通过分析牙源性基因表达（ALP，DSPP,DMP-1和VEGF）在人牙髓干细胞（DPSC）中使用RT-qPCR方法。表征研究表明,与SnHA相比,EnHA显示出更高的结晶度和优异的表面形态。复合支架显示出高度互连的多孔微结构，孔径在60至220μm之间，理想的细胞接种。所有测试材料,SnHA,EnHA,以及它们各自的复合材料，表现出很高的细胞相容性，增加ALP活性和矿化程度，DPSC上牙源性相关基因的显着上调（p<0.05）。然而，与SnHA-CMC相比,EnHA-CMC在DPSC上的牙源性分化潜能显著更高。这项研究的发现强调了EnHA-CMC作为牙髓牙本质工程的有希望的候选者的潜力。
