Application of Hydroxyapatite scaffold from Portunus pelagicus on OPG and RANKL expression after tooth extraction of Cavia cobaya

Objective: This study was to determine OPG and RANKL expression after hydroxyapatite (HA) scaffold from crab shells (Portunus pelagicus) application in tooth socket of Cavia cobaya. Methods: This study was a post-test only control group design. Twenty four Cavia cobaya was divided into 4 groups. The lower left incisor was extracted and given a combination of HA and gelatin scaffold. Experimental animals were sacrificed on the 7th and 14th day. The amount of OPG and RANKL expression was calculated under a light microscope at 1000x magnification. The statistical analysis was done by One Way ANOVA Test and Tukey HSD. Results: Compared to other groups, the lowest and the highest level of OPG and RANKL were in P14 group. Conclusion: HA scaffold from crab shells (Portunus pelagicus) can increase OPG expression and decrease RANKL expression in the process of regenerating alveolar bone after tooth extraction.

Degradable RGD-Functionalized 3D-Printed Scaffold Promotes Osteogenesis

To establish an ideal microenvironment for regenerating maxillofacial defects, recent research interests have concentrated on developing scaffolds with intricate configurations and manipulating the stiffness of extracellular matrix toward osteogenesis. Herein, we propose to infuse a degradable RGD-functionalized alginate matrix (RAM) with osteoid-like stiffness, as an artificial extracellular matrix, to a rigid 3D-printed hydroxyapatite scaffold for maxillofacial regeneration. The 3D-printed hydroxyapatite scaffold was produced by microextrusion technology and showed good dimensional stability with consistent microporous detail. RAM was crosslinked by calcium sulfate to manipulate the stiffness, and its degradation was accelerated by partial oxidation using sodium periodate. The results revealed that viability of bone marrow stem cells was significantly improved on the RAM and was promoted on the oxidized RAM. In addition, the migration and osteogenic differentiation of bone marrow stem cells were promoted on the RAM with osteoid-like stiffness, specifically on the oxidized RAM. The in vivo evidence revealed that nonoxidized RAM with osteoid-like stiffness upregulated osteogenic genes but prevented ingrowth of newly formed bone, leading to limited regeneration. Oxidized RAM with osteoid-like stiffness facilitated collagen synthesis, angiogenesis, and osteogenesis and induced robust bone formation, thereby significantly promoting maxillofacial regeneration. Overall, this study supported that in the stabilized microenvironment, oxidized RAM with osteoid-like stiffness offered requisite mechanical cues for osteogenesis and an appropriate degradation profile to facilitate bone formation. Combining the 3D-printed hydroxyapatite scaffold and oxidized RAM with osteoid-like stiffness may be an advantageous approach for maxillofacial regeneration.

Differential Expression Profiling of microRNAs in hPMSCs Co-culture With a Novel Porous Hydroxyapatite Scaffold

Background and objective: Scaffold materials used for bone defect repair are often limited by the osteogenic efficacy. Meanwhile, microRNAs (miRNAs) have been shown to be involved in regulating the expression of osteogenic related genes. In previous studies, we have verified that the enhancement of osteogenesis using a novel porous hydroxyapatite scaffold (HAG). In this study, we analyzed the contribution of HAG to osteogenic differentiation of Human placenta-derived mesenchymal stem cells (hPMSCs) from the perspective of miRNA differential expression.Methods: The properties of hPMSCs were identified by flow cytometry, including CD44, CD90 and CD45 surface marker. The expression of osteogenic differentiation related genes mRNA and protein were detected by quantitative real-time PCR (qRT-PCR) and western blotting. The mineral depositions were measured by Alizarin red S (ARS) staining. The miRNA profiles were performed by microarray assay, and then further summarized through target, gene ontology and pathway analysis. The expression of differential miRNA were verified by qRT-PCR.Results: The results showed that HAG promoted the osteogenic differentiation of hPMSCs. Meanwhile, sequencing results showed that 16 miRNAs were significantly up-regulated and 29 miRNAs were down-regulated with HAG. In addition, bioinformatics analyses showed that the differentially expressed miRNAs are involved in a variety of biological processes including signal transduction, cell metabolic, cell junction, cell development and differentiation and connect to osteogenic differentiation through axon guidance, MAPK, and TGF-beta signaling pathway. Furthermore, multiple potential target genes of miRNA are closely related to osteogenic differentiation.Conclusion: The work first confirmed that differential expression of miRNAs in the process of osteogenic differentiation promoted by HAG scaffold, which also lays the foundation for the further construction of bone scaffolds loaded with miRNAs.