scholarly journals Development of New Generation Bone Graft Material: Silver, Silicon Co-Substituted Apatite with Bi-Functional Properties

2014 ◽  
Vol 1626 ◽  
Author(s):  
Poon Nian Lim ◽  
Lei Chang ◽  
Bow Ho ◽  
Bee Yen Tay ◽  
Choong Cleo ◽  
...  
Keyword(s):  
Bone Graft ◽  
Functional Properties ◽  
Bone Mineral ◽  
Antibacterial Property ◽  
Synergistic Effects ◽  
Precipitation Method ◽  
Type I ◽  
Ageing Population ◽  
Graft Material ◽  
Medical Needs

ABSTRACTWith the rise of ageing population, the need to restore the function of degenerative bone greatly drives the market for bone grafts. Hydroxyapatite (HA) is chemically similar to natural bone mineral and has been widely used in bone graft applications. However, its slow osseointegration process and lack of antibacterial property could lead to implant-related infection, resulting in implant failure. Studies on ionic substitution of apatite have gained attention in recent years with greater understanding of the composition of bone mineral being a multi-substituted apatite. An integrated approach is proposed by co-substituting silver (Ag) and silicon (Si) into HA (Ag,Si-HA) to modify its surface for bi-functional properties. Incorporation of Si can enhance the biomineralization of HA and introduction of Ag can create antibacterial property. Ag,Si-HA containing 0.5 wt.% of Ag and 0.8 wt.% of Si was prepared by a wet precipitation method. A phase-pure apatite with a nanorod morphology of dimensions 60 nm in length and 10 nm in width was synthesized. Surface Ag+ ions of Ag,Si-HA were demonstrated to prevent the replication of adherent Staphylococcus aureus bacteria for up to 120 h. Biocompatibility tests revealed that human adipose-derived mesenchymal stem cells (hMSCs) proliferated well on Ag,Si-HA with culturing time. Enhanced cell attachment in turn permitted greater bone differentiation as evidenced in the increase of collagen type I and osteocalcin expressions of hMSCs cultured on Ag,Si-HA as compared to HA from day 14 onwards. Overall, co-substitution of Ag and Si could complement the benefits of each substituent by endowing HA with antibacterial property, and concurrently promoting its biological performance. Their synergistic effects can serve unmet medical needs and solve the problem of implant-related infection. This work also enhances the understanding of substituted apatite with multiple ions for bi-functional properties.

scholarly journals Loading and Release Profile Assay of Carbonated Hydroxyapatite Incorporated with Propolis as Bone Graft Material

2020 ◽  
Vol 25 (2) ◽  
pp. 121
Author(s):  
Indi Kusumawati ◽  
Suryono Suryono ◽  
Ahmad Syaify
Keyword(s):  
Bone Graft ◽  
Bacterial Adhesion ◽  
Alveolar Bone ◽  
Antibacterial Property ◽  
Graft Material ◽  
Synthetic Material ◽  
Carbonated Hydroxyapatite ◽  
Bone Graft Material ◽  
Absorbance Reading ◽  
The Difference

Periodontitis can lead to the destruction of the alveolar bone. The loss of the alveolar bone can be treated using carbonated hydroxyapatite (CHA) as a bone graft material. However, CHA is an alloplastic graft whose primary function is to act as a scaffold, but it is unable to stimulate the process of bone regeneration. Carbonated hydroxyapatite is an avascular synthetic material, which will increase the risk of bacterial adhesion on site that can lead to unsuccessful periodontal therapy. The incorporation of propolis into CHA is expected to add antibacterial capability into CHA. Besides its antibacterial property, propolis also has a bone regenerating effect. Mixing CHA with propolis needs to consider the process of loading the active ingredients into the carrier. The release of propolis is expected to occur gradually over a lengthy period. The purpose of this study was to analyze the loading and releasing assay for propolis incorporated with CHA. A propolis solution of 5%, 7.5%, and 10% was each incorporated into 10 mg of CHA. The loading percentage and releasing assay of propolis were measured. The absorbance reading was done at 289 nm using a UV-vis. It was shown that a 10% propolis solution had the highest loading percentage (32.08%), while the 5% propolis solution had the smallest loading percentage (10.63%). The propolis releasing profiles in all concentration groups were similar. The difference in propolis concentration incorporated with CHA affected the loading percentage but did not affect the propolis releasing assay.

scholarly journals The effect of autogenous tooth bone graft material without organic matter and type I collagen treatment on bone regeneration

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Min-Gu Kim ◽  
Jung-Han Lee ◽  
Gyoo-Cheon Kim ◽  
Dae-Seok Hwang ◽  
Chul-Hun Kim ◽  
...  
Keyword(s):  
Organic Matter ◽  
Bone Graft ◽  
Bone Regeneration ◽  
Bone Grafting ◽  
Type I Collagen ◽  
Treated Group ◽  
Control Group ◽  
Type I ◽  
Graft Material ◽  
Collagen Treatment

Abstract Objectives The aim of this study is to examine the effect of particulate autogenous tooth graft removed with organic matter and type I collagen addition on bone regeneration and to validate the possibility of useful allograft material for jaw defects. Material and methods Autogenous tooth bone maker (Korean Dental Solution® KOREA) made particulate autogenous tooth not including organic matter. We used to the developed tooth grafts for experiment. Cell adhesion test with hemacytometer and energy dispersive X-ray spectroscopy (Supra40 VP®, Carl Zeiss, Germany) analysis about the particulate autogenous tooth and type I collagen were performed. Rabbits were divided into three groups: bone graft with organic matter (OM) removing particulate autogenous tooth group, bone graft with OM removing particulate autogenous tooth and type I collagen group, and a control group. Bone grafting was performed in rabbit’s calvaria. The rabbits were sacrificed at different interval at 1, 2, 4, and 6 weeks after bone grafting for the histopathologic observation and observed the effect of bone regeneration by SEM, H-E & Masson stains, osteocalcin IHC staining. Result In vitro cytopathological study showed affinity for cells, cell attachment pattern, and cell proliferation in the order of control group, OM-removed and collagen-treated group, OM-removed particulate autogenous tooth group. The results of the degree of mineralization were opposite to those of the previous cell experimental results, and the OM-removed group, OM-removed group and collagen-treated group were relatively higher than the control group. Histopathologic analysis showed that vascularization and neonatal bone formation were higher in particulate autogenous tooth group with removing OM and with addition of collagen than control group and group of OM removed only. Immunohistochemical analysis showed that osteocalcin (OSC) expression was not observed in the control group, but at 4 weeks groups, OSC expression was observed the OM removed and OM-removed-collagen-treated particulate autogenous tooth, and the degree of expression was somewhat stronger in group of the OM removed and collagen additionally treated particulate autogenous tooth. Conclusion Particles that do not contain organic matter, the saint tooth, was responsible for sufficient bone graft material through the role of space maintenance and bone conduction, and further improved bone formation ability through additional collagen treatment. Therefore, research on various extracellular substrates and autologous bone grafting materials is necessary, and through this, it is possible to lay the foundation for a new type of autologous bone grafting material with excellent academic and technical utility.

Anorganic Bone Mineral Coated with Tetra-Cell Adhesion Molecule Enhances Bone Formation in Rabbit Calvarial Defects

2006 ◽  
Vol 309-311 ◽  
pp. 981-984
Author(s):  
Ji Ho Lee ◽  
Jin Woo Park ◽  
Byung Ju Choi ◽  
In San Kim ◽  
Jo Young Suh
Keyword(s):  
Cell Adhesion ◽  
Bone Formation ◽  
Bone Mineral ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Statistical Significance ◽  
Type I ◽  
Graft Material ◽  
New Bone Formation ◽  
Calvarial Defects

This study was performed to evaluate the effect of anorganic bone mineral (ABM) coated with Tetra-Cell Adhesion Molecule (T-CAM) for bone formation in rabbit calvarial defects and compare the capability of bone formation in ABM coated with T-CAM (ABM/T-CAM) to that in commercially available ABM coated with a synthetic peptide (P-15) which mimics the cell-binding domain of type I collagen, PepGen P-15TM. T-CAM composed of four cell adhesion molecules (RGD, PHSRN, EPDIM, and YH) was synthesized and ABM/T-CAM were prepared by absorbing T-CAM on ABM (OsteoGraf/N-300; Densply Friadent Ceramed Corp., USA). Two 9-mm diameter, full-thickness calvarial defects were made in each rabbit parietal bone and sixteen adult male rabbits were used in this experiment. The defects were reconstructed according to four treatment groups: unfilled, BM-grafted, PepGen P-15TM-grafted, and ABM/T-CAM-grafted. The animals were sacrificed at 2 and 4 weeks after surgery for histologic and histomorphometric evaluation. An active new bone formation were observed in the defects of ABM/T-CAM and PepGen P-15TM grafted groups at 2 and 4 weeks of healing in histologic observation. The results of histomorphometric analysis revealed higher new bone formation in ABM/T-CAM-grafted (14.62±0.6% at 2 weeks, 15.33±2.4% at 4 weeks) and PepGen P-15TM-grafted (12.46±1.0% at 2 weeks, 18.14±1.7% at 4 weeks) groups than in unfilled control (7.03±2.3% at 2 weeks, 8.71±3.4% at 4 weeks) and ABMgrafted (6.59±1.7% at 2 weeks, 9.25±0.8% at 4 weeks) groups at 2 and 4 weeks of healing with statistical significance (P<0.01). The results of this study indicated that the immobilizing T-CAM on ABM enhances the capability of bone substitutes to serve as an effective habitat for bone forming cells in vivo. In conclusion, we suggested that this composite graft material, ABM/T-CAM may be served as an effective tissue-engineered bone graft material in osseous reconstructive surgery.

scholarly journals Profiling PRMT methylome reveals roles of hnRNPA1 arginine methylation in RNA splicing and cell growth

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wen-juan Li ◽  
Yao-hui He ◽  
Jing-jing Yang ◽  
Guo-sheng Hu ◽  
Yi-an Lin ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Cell Growth ◽  
Rna Splicing ◽  
Synergistic Effects ◽  
Arginine Methylation ◽  
Type I ◽  
Prostate Cancer Cells ◽  
Cancer Cell Growth ◽  
Cancer Mutations ◽  
Substrate Spectrum

AbstractNumerous substrates have been identified for Type I and II arginine methyltransferases (PRMTs). However, the full substrate spectrum of the only type III PRMT, PRMT7, and its connection to type I and II PRMT substrates remains unknown. Here, we use mass spectrometry to reveal features of PRMT7-regulated methylation. We find that PRMT7 predominantly methylates a glycine and arginine motif; multiple PRMT7-regulated arginine methylation sites are close to phosphorylations sites; methylation sites and proximal sequences are vulnerable to cancer mutations; and methylation is enriched in proteins associated with spliceosome and RNA-related pathways. We show that PRMT4/5/7-mediated arginine methylation regulates hnRNPA1 binding to RNA and several alternative splicing events. In breast, colorectal and prostate cancer cells, PRMT4/5/7 are upregulated and associated with high levels of hnRNPA1 arginine methylation and aberrant alternative splicing. Pharmacological inhibition of PRMT4/5/7 suppresses cancer cell growth and their co-inhibition shows synergistic effects, suggesting them as targets for cancer therapy.

CSIG-17. IMMUNE MODULATORY ROLE OF TYPE I INTERFERON IN SYNGENEIC MOUSE GLIOMA MODELS

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi36-vi37
Author(s):  
Evelina Blomberg ◽  
Manuela Silginer ◽  
Michael Weller
Keyword(s):  
Tumor Cells ◽  
Immune Cell ◽  
Synergistic Effects ◽  
Xenograft Model ◽  
Prolonged Survival ◽  
Type I ◽  
Syngeneic Mouse ◽  
Glioma Initiating Cells ◽  
Glioma Growth

Abstract Glioblastoma is characterized by a poor prognosis and a challenging phenotype for drug development. Although multimodal treatment, including surgery, radio- and chemotherapy is applied, the overall survival remains just above one year. Numerous clinical trials have studied targeted therapies against commonly deregulated pathways, but an efficient targeted drug is yet to be discovered. Likewise, immunotherapy has not been shown to be active. A subset of glioma tumor cells demonstrates stem-like properties; these cells are commonly referred to as glioma initiating cells (GIC). These types of cells are pluripotent and can by definition initiate and recapitulate glioma growth in experimental animals in vivo. Furthermore, these cells are often resistant to conventional therapies. Interferon β (IFN-β) is an immunomodulatory molecule with anti-cancer properties. We have previously shown that IFN-β greatly reduces sphere-formation capability of GIC. It was also confirmed that IFN-β sensitized resistant GIC to irradiation or the chemotherapeutic agent, temozolomide (TMZ). IFN-β treatment significantly prolonged survival in a xenograft model with GIC cells. In the current project, we want to use syngeneic mouse models to study the immunomodulatory effects of type I IFNs. Preliminary results indicate that abrogation of IFN signalling in tumor cells by CRISPR/Cas9 technology prolonged survival in mice only in cell lines which have substantial baseline autocrine IFN signalling. On the contrary, we did not observe a difference in survival when wild-type tumor cells were implanted in either IFNAR1 deficient or proficient hosts. Flow cytometry analysis will elucidate changes in immune cell recruitment and infiltration upon IFN signalling disruption. Moreover, we explore different treatments in combination with IFN-β as there are indications that TMZ or radiotherapy can have synergistic effects with stimulation of interferon type I signalling.

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