scholarly journals Advantage of Alveolar Ridge Augmentation with Bioactive/Bioresorbable Screws Made of Composites of Unsintered Hydroxyapatite and Poly-L-lactide

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3681 ◽  
Author(s):  
Shintaro Sukegawa ◽  
Hotaka Kawai ◽  
Keisuke Nakano ◽  
Kiyofumi Takabatake ◽  
Takahiro Kanno ◽  
...  

We studied human bone healing characteristics and the histological osteogenic environment by using devices made of a composite of uncalcined and unsintered hydroxyapatite (u-HA) and poly-L-lactide (PLLA). In eight cases of fixation, we used u-HA/PLLA screws for maxillary alveolar ridge augmentation, for which mandibular cortical bone block was used in preimplantation surgery. Five appropriate samples with screws were evaluated histologically and immunohistochemically for runt-related transcription factor 2 (RUNX2), transcription factor Sp7 (Osterix), and leptin receptor (LepR). In all cases, histological evaluation revealed that bone components had completely surrounded the u-HA/PLLA screws, and the bone was connected directly to the biomaterial. Inflammatory cells did not invade the space between the bone and the u-HA/PLLA screw. Immunohistochemical evaluation revealed that many cells were positive for RUNX2 or Osterix, which are markers for osteoblast and osteoprogenitor cells, in the tissues surrounding u-HA/PLLA. In addition, many bone marrow–derived mesenchymal stem cells were notably positive for both LepR and RUNX2. The u-HA/PLLA material showed excellent bioactive osteoconductivity and a highly biocompatibility with bone directly attached. In addition, our findings suggest that many bone marrow–derived mesenchymal stem cells and mature osteoblast are present in the osteogenic environment created with u-HA/PLLA screws and that this environment is suitable for osteogenesis.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kulisara Marupanthorn ◽  
Chairat Tantrawatpan ◽  
Pakpoom Kheolamai ◽  
Duangrat Tantikanlayaporn ◽  
Sirikul Manochantr

AbstractMesenchymal stem cells (MSCs) are important in regenerative medicine because of their potential for multi-differentiation. Bone marrow, chorion and placenta have all been suggested as potential sources for clinical application. However, the osteogenic differentiation potential of MSCs derived from chorion or placenta is not very efficient. Bone morphogenetic protein-2 (BMP-2) plays an important role in bone development. Its effect on osteogenic augmentation has been addressed in several studies. Recent studies have also shown a relationship between miRNAs and osteogenesis. We hypothesized that miRNAs targeted to Runt-related transcription factor 2 (Runx-2), a major transcription factor of osteogenesis, are responsible for regulating the differentiation of MSCs into osteoblasts. This study examines the effect of BMP-2 on the osteogenic differentiation of MSCs isolated from chorion and placenta in comparison to bone marrow-derived MSCs and investigates the role of miRNAs in the osteogenic differentiation of MSCs from these sources. MSCs were isolated from human bone marrow, chorion and placenta. The osteogenic differentiation potential after BMP-2 treatment was examined using ALP staining, ALP activity assay, and osteogenic gene expression. Candidate miRNAs were selected and their expression levels during osteoblastic differentiation were examined using real-time RT-PCR. The role of these miRNAs in osteogenesis was investigated by transfection with specific miRNA inhibitors. The level of osteogenic differentiation was monitored after anti-miRNA treatment. MSCs isolated from chorion and placenta exhibited self-renewal capacity and multi-lineage differentiation potential similar to MSCs isolated from bone marrow. BMP-2 treated MSCs showed higher ALP levels and osteogenic gene expression compared to untreated MSCs. All investigated miRNAs (miR-31, miR-106a and miR148) were consistently downregulated during the process of osteogenic differentiation. After treatment with miRNA inhibitors, ALP activity and osteogenic gene expression increased over the time of osteogenic differentiation. BMP-2 has a positive effect on osteogenic differentiation of chorion- and placenta-derived MSCs. The inhibition of specific miRNAs enhanced the osteogenic differentiation capacity of various MSCs in culture and this strategy might be used to promote bone regeneration. However, further in vivo experiments are required to assess the validity of this approach.


2014 ◽  
Vol 33 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Koji Otabe ◽  
Hiroyuki Nakahara ◽  
Akihiko Hasegawa ◽  
Tetsuya Matsukawa ◽  
Fumiaki Ayabe ◽  
...  

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3848-3848
Author(s):  
Marilena Ciciarello ◽  
Valentina Salvestrini ◽  
Davide Ferrari ◽  
Sara Gulinelli ◽  
Roberta Zini ◽  
...  

Abstract Abstract 3848 Introduction: Human bone marrow derived Mesenchymal Stem Cells (hMSCs) are adult multipotent cells. hMSCs differentiate in vitro and in vivo into several tissue lineages originating from the three germinal layers making them attractive candidates for bioengineering and cellular therapy. Thus, it seems of great relevance to search putative messengers and signalling able to modulate their proliferation and differentiation. Nucleotides triphosphates are extracellular messengers binding to specific receptors (P2Rs) that modulate cell functions depending on the cell type. Controversial information is available on P2 expression and activity in hMSCs. Methods and Results: Here we found that hMSCs expressed several P2R subtypes. hMSCs were very resistant to the cytotoxic effects of high concentrations of ATP, as demonstrated by the lack of morphological and mitochondrial changes or release of intracellular markers of cell death. Gene expression profiling revealed that ATP treatment down-regulated cell proliferation and up-regulated cell migration genes in hMSCs. Functional studies confirmed the inhibitory activity of ATP on proliferation and clonogenic ability of hMSCs. Furthermore, ATP potentiated the chemotactic response of hMSCs to the chemokine CXCL12, and increased their spontaneous migration. In vivo, xenotransplant experiments showed that the homing capacity of hMSCs to murine bone marrow was increased by ATP pre-treatment. Moreover, ATP increased pro-inflammatory cytokines production (IL-2, IFN-g, IL-12p70), while decreased secretion of the anti-inflammatory cytokine IL-10. This finding was associated with the reduced ability of ATP-treated hMSC of inhibiting T-cell proliferation. Microarrays data suggested that several genes implicated in hMSC differentiation can be modulated by ATP treatment. To further investigate this issue, hMSCs cells were cultured under adipogenic or osteogenic conditions and were transiently exposed to ATP before starting differentiation or continuously exposed to ATP for the first 3 days of differentiation induction. We demonstrated that adipogenesis-related accumulation of lipids, analyzed by Oil red O staining, was more evident in ATP treated cultures. Furthermore, quantitative real time PCR (qRT-PCR) assay showed that mRNA expression of PPARg, a transcription factor early up-regulated during adipogenesis, was significantly increased in hMSCs differentiated cells treated with ATP. In osteogenic condition, analysis of mineralized area through Alizarin Red staining, indicated that ATP treatment enhanced the extent of mineralization compared to untreated control. The expression of RUNX2, a key transcription factor in osteogenesis, analyzed by qRT-PCR in differentiated cells confirmed data obtained in Alizarin-based assay. Conclusions: These data demonstrated that purinergic signalling modulates biological functions and differentiation potential of hMSCs. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Frank Schwarz ◽  
Didem Sahin ◽  
Sara Civale-Schweighöfer ◽  
Jürgen Becker

Abstract Objectives To assess the long-term clinical outcomes following lateral alveolar ridge augmentation using a collagenated xenogeneic bone block (CXBB) and staged implant placement. Material and methods A total of n = 9 patients (9 implants) were available for the analysis. Each subject had received lateral ridge augmentation using a size-adapted rigidly fixed CXBB and contour augmentation at single-tooth gaps. Implant placement was performed after 24 weeks of submerged healing. Clinical parameters (e.g., bleeding on probing (BOP), probing pocket depth (PD), mucosal recession (MR)) were recorded at 16 to 20 weeks after the cementation of the crown (baseline) and scheduled for 0.5 (visit 1 (V1)), 1.5 (V2), 2.5 (V3), 3.5 (V4), and 4.5 (V5) years after implant loading. Results Changes in clinical parameters commonly remained low throughout the entire observation period. Significant changes to baseline were merely noted for mean BOP scores at V4 (19.14 ± 17.75%; n = 7; P = 0.029) and mean PD scores at V2 (0.78 ± 0.98 mm; n = 9; P = 0.044) and V3 (1.33 ± 1.05 mm; n = 9; P = 0.009), respectively. Conclusion CXBB was associated with high clinical implant success and survival rates on the long-term.


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