scholarly journals Silicate/zinc-substituted strontium apatite coating improves the osteoinductive properties of β-tricalcium phosphate bone graft substitute

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hironori Sugimoto ◽  
Yusuke Inagaki ◽  
Akira Furukawa ◽  
Tsutomu Kira ◽  
Sachiko Kawasaki ◽  
...  

Abstract Background β-Tricalcium phosphate (β-TCP) is a popular synthetic bone graft substitute with excellent osteoconductive properties and bioabsorbability. However, its osteoinductive properties are inferior to those of autologous or allogeneic bone. Trace elements such as strontium (Sr), silica (Si), and zinc (Zn) have been reported to promote osteogenesis in materials. In this study, we aimed to determine whether a Si/Zn-substituted Sr apatite coating of β-TCP could enhance osteoinductive properties. Methods The apatite-coated β-TCP disks were prepared using nanoparticle suspensions of silicate-substituted Sr apatite (SrSiP) or silicate- and Zn-co-substituted Sr apatite (SrZnSiP). Bone marrow mesenchymal cells (BMSCs) from rat femur were cultured and subsequently seeded at a density of 1.0 × 106/cm2 onto apatite-coated and non-coated β-TCP disks. In vitro, the β-TCP disks were then placed in osteogenic medium, and lactate dehydrogenase (LDH) activity was measured from supernatants after culture for 2 days. Additionally, after culture for 14 days, the mRNA expression of genes encoding osteocalcin (OC), alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP-2), and vascular endothelial growth factor (VEGF) was evaluated by qRT-PCR. In vivo, the β-TCP disks were transplanted subcutaneously into rats that were sacrificed after 4 weeks. Then, the harvested disks were evaluated biochemically (ALP activity, OC content, mRNA expression of OC, ALP, BMP-2, and VEGF measured by qRT-PCR), radiologically, and histologically. Results Significantly higher mRNA expression of almost all evaluated osteogenic and angiogenic genes was observed in the SrZnSiP and SrSiP groups than in the non-coated group, with no significant cytotoxicity elicited by the apatite coating in vitro. Moreover, in vivo, the SrZnSiP and SrSiP groups showed significantly higher osteogenic and angiogenic gene expression and higher ALP activity and OC content than the non-coated group (P < 0.05). Radiological and histopathological findings revealed abundant bone formation in the apatite-coated group. Conclusions Our findings indicate that apatite coating of β-TCP improves osteoinductive properties without inducing significant cytotoxicity.

2021 ◽  
Author(s):  
Hironori Sugimoto ◽  
Yusuke Inagaki ◽  
Akira Furukawa ◽  
Tsutomu Kira ◽  
Sachiko Kawasaki ◽  
...  

Abstract Background: β-Tricalcium phosphate (β-TCP) is a popular synthetic bone graft substitute with excellent osteoconductive properties and bioabsorbability. However, its osteoinductive properties are inferior to those of autologous or allogeneic bone. Trace elements such as strontium (Sr), silica (Si), and zinc (Zn) have been reported to promote osteogenesis in materials. In this study, we aimed to determine whether a Si/Zn-substituted Sr apatite coating of β-TCP could enhance osteoinductive properties.Methods: The apatite-coated β-TCP disks were prepared using nanoparticle suspensions of silicate-substituted Sr apatite (SrSiP) or silicate- and Zn-co-substituted Sr apatite (SrZnSiP).Bone marrow mesenchymal cells (BMSCs) from rat femur were cultured and subsequently seeded at a density of 1.0 × 106/cm2 onto apatite-coated and non-coated β-TCP disks.In vitro, the β-TCP disks were then placed in osteogenic medium, and lactate dehydrogenase (LDH) activity was measured from supernatants after culture for 2 days. Additionally, after culture for 14 days, the mRNA expression of genes encoding osteocalcin (OC), alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP-2), and vascular endothelial growth factor (VEGF) was evaluated by qRT-PCR. In vivo, the β-TCP disks were transplanted subcutaneously into rats that were sacrificed after 4 weeks. Then, the harvested disks were evaluated biochemically (ALP activity, OC content, mRNA expression of OC, ALP, BMP-2, and VEGF measured by qRT-PCR), radiologically, and histologically.Results: Significantly higher mRNA expression of almost all evaluated osteogenic and angiogenic genes was observed in the SrZnSiP and SrSiP groups than in the non-coated group, with no significant cytotoxicity elicited by the apatite coating in vitro. Moreover, in vivo, the SrZnSiP and SrSiP groups showed significantly higher osteogenic and angiogenic gene expression and higher ALP activity and OC content than the non-coated group (P < 0.05). Radiological and histopathological findings revealed abundant bone formation in the apatite-coated group.Conclusions: Our findings indicate that apatite coating of β-TCP improves osteoinductive properties without inducing significant cytotoxicity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nan Jiang ◽  
Devendra H. Dusane ◽  
Jacob R. Brooks ◽  
Craig P. Delury ◽  
Sean S. Aiken ◽  
...  

AbstractThis study investigated the efficacy of a biphasic synthetic β-tricalcium phosphate/calcium sulfate (β-TCP/CS) bone graft substitute for compatibility with vancomycin (V) in combination with tobramycin (T) or gentamicin (G) evidenced by the duration of potency and the prevention and killing efficacies of P. aeruginosa (PAO1) and S. aureus (SAP231) biofilms in in vitro assays. Antibiotic loaded β-TCP/CS beads were compared with antibiotic loaded beads formed from a well characterized synthetic calcium sulfate (CS) bone void filler. β-TCP/CS antibiotic loaded showed antimicrobial potency against PAO1 in a repeated Kirby-Bauer like zone of inhibition assay for 6 days compared to 8 days for CS. However, both bead types showed potency against SAP231 for 40 days. Both formulations loaded with V + T completely prevented biofilm formation (CFU below detection limits) for the 3 days of the experiment with daily fresh inoculum challenges (P < 0.001). In addition, both antibiotic loaded materials and antibiotic combinations significantly reduced the bioburden of pre-grown biofilms by between 3 and 5 logs (P < 0.001) with V + G performing slightly better against PAO1 than V + T. Our data, combined with previous data on osteogenesis suggest that antibiotic loaded β-TCP/CS may have potential to stimulate osteogenesis through acting as a scaffold as well as simultaneously protecting against biofilm infection. Future in vivo experiments and clinical investigations are warranted to more comprehensively evaluate the use of β-TCP/CS in the management of orthopaedic infections.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4200-4200
Author(s):  
Miroslav Koulnis ◽  
Homare Eda ◽  
Loredana Santo ◽  
Ka Tat Siu ◽  
Janani Ramachandran ◽  
...  

Abstract Model systems to study Multiple Myeloma (MM) related bone disease exist but have a number of limitations. Disseminated MM models have variable cell homing and do not precisely recapitulate the human microenvironment interactions with myeloma cells. Severe combined immunodeficiency (SCID) mice engrafted with human fetal bone (SCID-hu) have been used by us, and are able to recapitulate the human bone marrow microenvironment. The fetal bone chips are however difficult to obtain, and vary in size and shape, complicating inter-sample comparison. Similarly, the poly-ε-caprolactone polymeric scaffold, previously used to seed murine or human stromal compartment, may not correctly reproduce bone destruction and inhibition of osteogenesis by MM as seen in patients, making this model difficult to test therapies targeting the MM niche. β-tricalcium phosphate (β-TCP) is a biocompatible and biodegradable bone graft substitute that is uniform in structure and easily available, and may be a viable alternative to overcome SCID-hu difficulties in modeling MM bone disease. Here, we utilized β-TCP bone graft substitute to develop a novel in vivo MM model where β-TCP permits the development of the bone microenvironment, supports MM development, and is technically feasible and highly reproducible. Using this model, we aim to better understand the biology of the niche in MM by genetically modifying its components and by testing new niche-targeting therapies. Our initial results show that osteogenesis takes place in the β-TCP bone graft, and the implant is supportive of MM tumor growth. Inter-scapular subcutaneous implantation of β-TCP alone, or co-implantation with human-derived stromal cell line HS27A in immunocompromised recipients resulted in the expression of osteogenic markers Runx2, alkaline phosphatase (ALP), Col1A1, and Osteocalcin (OCN), as well as a marker of bone resorption. Further, implants supported the growth of human-derived MM1.S and murine 5TGM1 cells, as visualized directly in vivo by serial luciferase bioluminescence imaging (BLI) and by immunohistochemistry. Modifying the niche compartment in Cre/iDTR animals with MM disease is an exciting novel strategy to understand which niche component in vivo may be targeted to suppress MM development. Mouse strains with promoter-specific Cre recombinase that induces the expression of the diphtheria toxin (DT) receptor (iDTR) can be utilized to selectively ablate a cell population of interest in vivo, via intraperitoneal DT injection. Here, we first utilized OCN-Cre/iDTR mice to test the deletion of mature osteoblasts in β-TCP artificial bone graft post-implantation. Our data show a dose-dependent reduction in osteoblastic markers OCN, ALP, Runx2, Sclerostin, Osteoprotegerin and RANKL. Importantly, DT ablation of osteoblasts in the β-TCP implant resulted in a significantly increased 5TGM1 tumor growth, as judged by BLI and tumor weight. Our data show that the mature osteocalcin-positive niche population is protective against MM disease. Ongoing studies of the β-TCP mouse model will address the relative contribution of various osteogenic populations to the course of MM development in vivo, and test the efficacy of novel MM drugs. Disclosures Raje: BMS: Consultancy; Amgen: Consultancy; Celgene Corporation: Consultancy; Takeda: Consultancy; Onyx: Consultancy; Takeda: Consultancy; Amgen: Consultancy; Onyx: Consultancy; BMS: Consultancy; AstraZeneca: Research Funding; Eli Lilly: Research Funding; AstraZeneca: Research Funding; Millenium: Consultancy; Eli Lilly: Research Funding; Novartis: Consultancy; Acetylon: Research Funding; Millenium: Consultancy; Novartis: Consultancy; Acetylon: Research Funding.


2011 ◽  
Vol 300 (2) ◽  
pp. G316-G326 ◽  
Author(s):  
Melania Scarpa ◽  
Alessia R. Grillo ◽  
Paola Brun ◽  
Veronica Macchi ◽  
Annalisa Stefani ◽  
...  

Following liver injury, the wound-healing process is characterized by hepatic stellate cell (HSC) activation from the quiescent fat-storing phenotype to a highly proliferative myofibroblast-like phenotype. Snail1 is a transcription factor best known for its ability to trigger epithelial-mesenchymal transition, to influence mesoderm formation during embryonic development, and to favor cell survival. In this study, we evaluated the expression of Snail1 in experimental and human liver fibrosis and analyzed its role in the HSC transdifferentiation process. Liver samples from patients with liver fibrosis and from mice treated by either carbon tetrachloride (CCl4) or thioacetamide (TAA) were evaluated for mRNA expression of Snail1. The transcription factor expression was investigated by immunostaining and real-time quantitative RT-PCR (qRT-PCR) on in vitro and in vivo activated murine HSC. Snail1 knockdown studies on cultured HSC and on CCl4-treated mice were performed by adenoviral delivery of short-hairpin RNA; activation-related genes were quantitated by real-time qRT-PCR and Western blotting. Snail1 mRNA expression resulted upregulated in murine experimental models of liver injury and in human hepatic fibrosis. In vitro studies showed that Snail1 is expressed by HSC and that its transcription is augmented in in vitro and in vivo activated HSC compared with quiescent HSC. At the protein level, we could observe the nuclear translocation of Snail1 in activated HSC. Snail1 knockdown resulted in the downregulation of activation-related genes both in vitro and in vivo. Our data support a role for Snail1 transcription factor in the hepatic wound-healing response and its involvement in the HSC transdifferentiation process.


2015 ◽  
Vol 27 (03) ◽  
pp. 1550028 ◽  
Author(s):  
Kam-Kong Chan ◽  
Chia-Hsien Chen ◽  
Lien-Chen Wu ◽  
Yi-Jie Kuo ◽  
Chun-Jen Liao ◽  
...  

Calcium phosphate ceramics, of a similar composition to that of mineral bone, and which possess the properties of bioactivity and osteoconductivity, have been widely used as substitutes for bone graft in orthopedic, plastic and craniofacial surgeries. A synthetic β-tricalcium phosphate, Osteocera™, a recently developed bone graft substitute, has been used in this study. To evaluate the affinity and efficacy of Osteocera™ as bone defect implant, we used a New Zealand white rabbit femur defect model to test the osteoconductivity of this new bone substitute. Alternative commercially available bone substitutes, Triosite® and ProOsteon500, were used as the control materials. These three bone substitutes show good biocompatibility, and no abnormal inflammation either infection was seen at the implantation sites. In the histological and histomorphometric images, newly formed bone grew into the peripheral pores in the bone substitutes. After six months implantation, the volume of bone formation was found to be 20.5 ± 5.2%, 29.8 ± 6.5% and 75.5 ± 4.9% of the potential total cavity offered by ProOsteon500, Triosite® and Osteocera™, respectively. The newly formed bone area within the femur defect section for Osteocera™ was significantly larger than ProOsteon500 and Triosite®. We concluded that Osteocera™ shows better bioresorbability, biocompatibility and osteoconductivity in the rabbit femur defect model.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Endang Wahyuningtyas ◽  
Ling-Chuan Hsu ◽  
Wen-Chien Lan ◽  
Shih-Cheng Wen ◽  
Keng-Liang Ou ◽  
...  

The purpose of thehttp://mts.hindawi.com/update/) in our Manuscript Tracking System and after you have logged in click on the ORCID link at the top of the page. This link will take you to the ORCID website where you will be able to create an account for yourself. Once you have done so, your new ORCID will be saved in our Manuscript Tracking System automatically."?> present study was to investigate the effect of local hydroxyapatite (HA) combined with extracted sea cucumber (Stichopus hermanni) collagen as a promising bone graft substitute on bone remodeling. Fourier-transform infrared spectroscopy, X-ray diffractometry, transmission electron microscopy, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and Sprague-Dawley rat model were used to characterize the microstructure, in vitro cytotoxicity, and in vivo bone-healing properties of the investigated biocomposite material. Analytical results found that the hydrothermal reaction-synthesized local HA had a hexagonal close-packed structure. The addition of extracted S. hermanni collagen did not influence the microstructure and functional groups of the local HA. Moreover, the MTT assay indicated that the investigated biocomposite material possessed a good in vitro biocompatibility. The in vivo animal study also revealed that the investigated biocomposite material exhibited the highest number of osteoblasts after 14 days of healing. Therefore, the results demonstrate that the local HA combined with extracted S. hermanni collagen could potentially enhance osteoblast formation in promoting bone healing and regeneration.


2020 ◽  
Vol 18 ◽  
Author(s):  
Zirui Zhang ◽  
Shangcong Han ◽  
Panpan Liu ◽  
Xu Yang ◽  
Jing Han ◽  
...  

Background: Chronic inflammation and lack of angiogenesis are the important pathological mechanisms in deep tissue injury (DTI). Curcumin is a well-known anti-inflammatory and antioxidant agent. However, curcumin is unstable under acidic and alkaline conditions, and can be rapidly metabolized and excreted in the bile, which shortens its bioactivity and efficacy. Objective: This study aimed to prepare curcumin-loaded poly (lactic-co-glycolic acid) nanoparticles (CPNPs) and to elucidate the protective effects and underlying mechanisms of wound healing in DTI models. Methods: CPNPs were evaluated for particle size, biocompatibility, in vitro drug release and their effect on in vivo wound healing. Results : The results of in vivo wound closure analysis revealed that CPNP treatments significantly improved wound contraction rates (p<0.01) at a faster rate than other three treatment groups. H&E staining revealed that CPNP treatments resulted in complete epithelialization and thick granulation tissue formation, whereas control groups resulted in a lack of compact epithelialization and persistence of inflammatory cells within the wound sites. Quantitative real-time PCR analysis showed that treatment with CPNPs suppressed IL-6 and TNF-α mRNA expression, and up-regulated TGF-β, VEGF-A and IL-10 mRNA expression. Western blot analysis showed up-regulated protein expression of TGF-β, VEGF-A and phosphorylatedSTAT3. Conclusion: Our results showed that CPNPs enhanced wound healing in DTI models, through modulation of the JAK2/STAT3 signalling pathway and subsequent upregulation of pro-healing factors.


Author(s):  
Niketa Chauhan ◽  
Nilay Lakhkar ◽  
Amol Chaudhari

AbstractThe process of bone regeneration in bone grafting procedures is greatly influenced by the physicochemical properties of the bone graft substitute. In this study, porous phosphate glass (PPG) morsels were developed and their physicochemical properties such as degradation, crystallinity, organic content, surface topography, particle size and porosity were evaluated using various analytical methods. The in vitro cytotoxicity of the PPG morsels was assessed and the interaction of the PPG morsels with Dental Pulp Stem Cells (DPSCs) was studied by measuring cell proliferation and cell penetration depth. The cell-material interactions between PPG morsels and a commercially available xenograft (XG) were compared. The PPG morsels were observed to be amorphous, biocompatible and highly porous (porosity = 58.45%). From in vitro experiments, PPG morsels were observed to be non-cytotoxic and showed better cell proliferation. The internal surface of PPG was easily accessible to the cells compared to XG.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Xiaoping Zhang ◽  
Dan Li ◽  
Chengyou Jia ◽  
Haidong Cai ◽  
Zhongwei Lv ◽  
...  

Abstract Background Papillary thyroid cancer (PTC) is the most common type of cancer of the endocrine system. Long noncoding RNAs (lncRNAs) are emerging as a novel class of gene expression regulators associated with tumorigenesis. Through preexisting databases available for differentially expressed lncRNAs in PTC, we uncovered that lncRNA OIP5-AS1 was significantly upregulated in PTC tissues. However, the function and the underlying mechanism of OIP5-AS1 in PTC are poorly understood. Methods Expression of lncRNA OIP5-AS1 and miR-98 in PTC tissue and cells were measured by quantitative real-time PCR (qRT-PCR). And expression of METTL14 and ADAMTS8 in PTC tissue and cells were measured by qRT-PCR and western blot. The biological functions of METTL14, OIP5-AS1, and ADAMTS8 were examined using MTT, colony formation, transwell, and wound healing assays in PTC cells. The relationship between METTL14 and OIP5-AS1 were evaluated using RNA immunoprecipitation (RIP) and RNA pull down assay. And the relationship between miR-98 and ADAMTS8 were examined by luciferase reporter assay. For in vivo experiments, a xenograft model was used to investigate the effects of OIP5-AS1 and ADAMTS8 in PTC. Results Functional validation revealed that OIP5-AS1 overexpression promotes PTC cell proliferation, migration/invasion in vitro and in vivo, while OIP5-AS1 knockdown shows an opposite effect. Mechanistically, OIP5-AS1 acts as a target of miR-98, which activates ADAMTS8. OIP5-AS1 promotes PTC cell progression through miR-98/ADAMTS8 and EGFR, MEK/ERK pathways. Furthermore, RIP and RNA pull down assays identified OIP5-AS1 as the downstream target of METTL14. Overexpression of METTL14 suppresses PTC cell proliferation and migration/invasion through inhibiting OIP5-AS1 expression and regulating EGFR, MEK/ERK pathways. Conclusions Collectively, our findings demonstrate that OIP5-AS1 is a METTL14-regulated lncRNA that plays an important role in PTC progression and offers new insights into the regulatory mechanisms underlying PTC development.


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