scholarly journals In Vivo and In Vitro Analyses of Titanium-Hydroxyapatite Functionally Graded Material for Dental Implants

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xinhua Wang ◽  
Chengpeng Wan ◽  
Xiaoxia Feng ◽  
Fuyan Zhao ◽  
Huiming Wang

Purpose. The stress shielding effect caused due to the mechanical mismatch between the solid titanium and the surrounding bone tissue warrants the utilization of a mechanically and biologically compatible material such as the titanium-hydroxyapatite (Ti-HA) functionally graded material (FGM) for dental implants. This study is aimed at fabricating a Ti-HA FGM with superior mechanical and biological properties for dental implantation. Materials and Methods. We fabricated a Ti-HA FGM with different Ti volume fractions (VFs) using HA and Ti powders. Ti-HA was characterized by studying its mechanical properties. Cytotoxicity was examined using a Cell Counting Kit-8 assay and an LDH cell cytotoxicity assay. Scanning electron microscopy was performed on an XL30 environmental scanning electron microscope (ESEM). Alkaline phosphatase (ALP) and transforming growth factor (TGF-β1) expressions were quantitatively monitored using enzyme-linked immunosorbent assay (ELISA) kits. The expressions of TGF-β receptors and ALP genes were measured using real-time polymerase chain reaction. The Ti-HA FGM dental implants were placed in beagle dogs. Microcomputed tomography (CT) and hard tissue slices were performed to evaluate the bone-implant contact (BIC) and bone volume over total volume (BV/TV). Results. The density and mechanical properties of the Ti-HA exhibited various graded distributions corresponding to VF. Based on the results of the Cell Counting Kit-8 (CCK-8) and lactate dehydrogenase (LDH) assays, the difference in cytotoxicity between the two groups was statistically nonsignificant ( P = 0.11 ). The ALP and TGF-β1 levels were slightly upregulated. The transcript levels of ALP and TGF-βRI were higher in the Ti-HA groups than in the Ti group at 7 days, whereas the transcript levels of TGF-βRII exhibited no obvious increase. The BIC did not exhibit significant differences between the Ti and Ti-HA FGM groups ( P = 0.0504 ). BV/TV showed the Ti-HA FGM group had better osteogenesis ( P = 0.04 ). Conclusion. Ti-HA FGM contributes to the osteogenesis of dental implants in vivo and in vitro.

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Longpeng Dong ◽  
Qingli Liu ◽  
Yongli Gao ◽  
Hengxing Jia ◽  
Wenling Dai ◽  
...  

Abstract Collagen is a promising material for tissue engineering, but the poor mechanical properties of collagen hydrogels, which tend to cause contraction under the action of cellular activity, make its application challengeable. In this study, the amino group of type I collagen (Col I) was modified with methacrylic anhydride (MA) and the photo-crosslinkable methacrylate anhydride modified type I collagen (CM) with three different degrees of substitution (DS) was prepared. The physical properties of CM and Col I hydrogels were tested, including micromorphology, mechanical properties and degradation properties. The results showed that the storage modulus and degradation rate of hydrogels could be adjusted by changing the DS of CM. In vitro, chondrocytes were seeded into these four groups of hydrogels and subjected to fluorescein diacetate/propidium iodide (FDA/PI) staining, cell counting kit-8 (CCK-8) test, histological staining and cartilage-related gene expression analysis. In vivo, these hydrogels encapsulating chondrocytes were implanted subcutaneously into nude mice, then histological staining and sulfated glycosaminoglycan (sGAG)/DNA assays were performed. The results demonstrated that contraction of hydrogels affected behaviors of chondrocytes, and CM hydrogels with suitable DS could resist contraction of hydrogels and promote the secretion of cartilage-specific matrix in vitro and in vivo.


2021 ◽  
Vol 22 (4) ◽  
pp. 1985
Author(s):  
Xiaohe Li ◽  
Ling Ma ◽  
Kai Huang ◽  
Yuli Wei ◽  
Shida Long ◽  
...  

Idiopathic pulmonary fibrosis (IPF) is a fatal and age-related pulmonary disease. Nintedanib is a receptor tyrosine kinase inhibitor, and one of the only two listed drugs against IPF. Regorafenib is a novel, orally active, multi-kinase inhibitor that has similar targets to nintedanib and is applied to treat colorectal cancer and gastrointestinal stromal tumors in patients. In this study, we first identified that regorafenib could alleviate bleomycin-induced pulmonary fibrosis in mice. The in vivo experiments indicated that regorafenib suppresses collagen accumulation and myofibroblast activation. Further in vitro mechanism studies showed that regorafenib inhibits the activation and migration of myofibroblasts and extracellular matrix production, mainly through suppressing the transforming growth factor (TGF)-β1/Smad and non-Smad signaling pathways. In vitro studies have also indicated that regorafenib could augment autophagy in myofibroblasts by suppressing TGF-β1/mTOR (mechanistic target of rapamycin) signaling, and could promote apoptosis in myofibroblasts. In conclusion, regorafenib attenuates bleomycin-induced pulmonary fibrosis by suppressing the TGF-β1 signaling pathway.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Qilu Wei ◽  
Ning Kong ◽  
Xiaohui Liu ◽  
Run Tian ◽  
Ming Jiao ◽  
...  

Abstract Background Osteoarthritis (OA) is a disease of the entire joint involving synovial fibrosis and inflammation. Pathological changes to the synovium can accelerate the progression of OA. Pirfenidone (PFD) is a potent anti-fibrotic drug with additional anti-inflammatory properties. However, the influence of PFD on OA is unknown. Methods Proliferation of human fibroblast-like synoviocytes (FLSs) after treatment with TGF-β1 or PFD was evaluated using a Cell Counting Kit-8 assay and their migration using a Transwell assay. The expression of fibrosis-related genes (COL1A1, TIMP-1, and ACTA-2) and those related to inflammation (IL-6 and TNF-α) was quantified by real-time quantitative PCR. The protein expression levels of COL1A1, α-SMA (coded by ACTA-2), IL-6 and TNF-α were measured by enzyme-linked immunosorbent assay. A rabbit model of OA was established and then PFD was administered by gavage. The expression of genes related to fibrosis (COL1A1, TIMP-1, and ADAM-12) and inflammation (IL-6 and TNF-α) was measured using RNA extracted from the synovium. Synovial tissue was examined histologically after staining with H&E, Masson’s trichrome, and immunofluorescence. Synovitis scores, the volume fraction of collagen, and mean fluorescence intensity were calculated. Degeneration of articular cartilage was analyzed using a Safranin O-fast green stain and OARSI grading. Results The proliferation of FLSs was greatest when induced with 2.5 ng/ml TGF-β1 although it did not promote their migration. Therefore, 2.5 ng/ml TGF-β1 was used to stimulate the FLSs and evaluate the effects of PFD, which inhibited the migration of FLSs at concentrations as low as 1.0 mg/ml. PFD decreased the expression of COL1A1 while TGF-β1 increased both mRNA and protein expression levels of IL-6 but had no effect on α-SMA or TNF-α expression. PFD decreased mRNA expression levels of COL1A1, IL-6, and TNF-α in vivo. H&E staining and synovitis scores indicated that PFD reduced synovial inflammation, while Masson’s trichrome and immunofluorescence staining suggested that PFD decreased synovial fibrosis. Safranin O-Fast Green staining and the OARSI scores demonstrated that PFD delayed the progression of OA. Conclusions PFD attenuated synovial fibrosis and inflammation, and postponed the progression of osteoarthritis in a modified Hulth model of OA in rabbits, which was related to its anti-fibrotic and anti-inflammatory properties.


Author(s):  
Pia‐Merete Jervøe‐Storm ◽  
Alexandra Selina Hablützel ◽  
Philipp Bartels ◽  
Dominik Kraus ◽  
Søren Jepsen ◽  
...  

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xixi Li ◽  
Shengli Hu ◽  
Haitao Yin ◽  
Hongbo Zhang ◽  
Dan Zhou ◽  
...  

Abstract Background Culex pipiens (Cx. pipiens) complex, which acts as a vector of viruses and is widespread and abundant worldwide, including West Nile virus, Japanese encephalitis virus, and Sindbis virus, can cause serious vector-borne diseases affecting human health. Unfortunately, mosquitoes have developed deltamethrin resistance because of its long-term overuse, representing a major challenge to mosquito control. Understanding the molecular regulatory mechanisms of resistance is vital to control mosquitoes. MicroRNAs (miRNAs) are short non-coding RNAs that have been demonstrated to be important regulators of gene expression across a wide variety of organisms, which might function in mosquito deltamethrin resistance. In the present study, we aimed to investigate the regulatory functions of miR-4448 and CYP4H31 in the formation of insecticidal resistance in mosquito Culex pipiens pallens. Methods We used quantitative real-time reverse transcription PCR to measure miR-4448 and CYP4H31 (encoding a cytochrome P450) expression levels. The regulatory functions of miR-4448 and CYP4H31 were assessed using dual-luciferase reporter assays. Then, oral feeding, RNA interference, and the American Centers for Disease Control and Prevention bottle bioassay were used to determine miR-4448’s association with deltamethrin resistance by targeting CYP4H31in vivo. Cell Counting Kit-8 (CCK-8) was also used to detect the viability of pIB/V5-His-CYP4H31-transfected C6/36 cells after deltamethrin treatment in vitro. Results MiR-4448 was downregulated in the deltamethrin-resistant strain (DR strain), whereas CYP4H31 was downregulated in deltamethrin-susceptible strain. CYP4H31 expression was downregulated by miR-4448 recognizing and binding to its 3′ untranslated region. Functional verification experiments showed that miR-4448 overexpression resulted in lower expression of CYP4H31. The mortality of miR-4448 mimic-injected DR strain mosquitoes was higher than that of the controls. CCK-8 assays showed that CYP4H31 decreased cellular resistance to deltamethrin in vitro and the mortality of the DR strain increased when CYP4H31 was knocked down in vivo. Conclusions In mosquitoes, miR-4448 participates in deltamethrin resistance by targeting CYP4H31. The results of the present study increase our understanding of deltamethrin resistance mechanisms.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryosuke Nakamura ◽  
Nao Hiwatashi ◽  
Renjie Bing ◽  
Carina P. Doyle ◽  
Ryan C. Branski

AbstractVocal fold (VF) fibrosis is a major cause of intractable voice-related disability and reduced quality of life. Excision of fibrotic regions is suboptimal and associated with scar recurrence and/or further iatrogenic damage. Non-surgical interventions are limited, putatively related to limited insight regarding biochemical events underlying fibrosis, and downstream, the lack of therapeutic targets. YAP/TAZ integrates diverse cell signaling events and interacts with signaling pathways related to fibrosis, including the TGF-β/SMAD pathway. We investigated the expression of YAP/TAZ following vocal fold injury in vivo as well as the effects of TGF-β1 on YAP/TAZ activity in human vocal fold fibroblasts, fibroblast-myofibroblast transition, and TGF-β/SMAD signaling. Iatrogenic injury increased nuclear localization of YAP and TAZ in fibrotic rat vocal folds. In vitro, TGF-β1 activated YAP and TAZ in human VF fibroblasts, and inhibition of YAP/TAZ reversed TGF-β1-stimulated fibroplastic gene upregulation. Additionally, TGF-β1 induced localization of YAP and TAZ in close proximity to SMAD2/3, and nuclear accumulation of SMAD2/3 was inhibited by a YAP/TAZ inhibitor. Collectively, YAP and TAZ were synergistically activated with the TGF-β/SMAD pathway, and likely essential for the fibroplastic phenotypic shift in VF fibroblasts. Based on these data, YAP/TAZ may evolve as an attractive therapeutic target for VF fibrosis.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
JiangSheng Zhao ◽  
GuoFeng Chen ◽  
Jingqi Li ◽  
Shiqi Liu ◽  
Quan Jin ◽  
...  

Abstract Background PR55α plays important roles in oncogenesis and progression of numerous malignancies. However, its role in hepatocellular carcinoma (HCC) is unclear. This study aims to characterize the functions of PR55α in HCC. Methods PR55α expressions in HCC tissues and paired healthy liver samples were evaluated using Western blot and tissue microarray immunohistochemistry. We knocked down the expression of PR55α in SMMC-7721 and LM3 cell lines via small interfering and lentivirus. In vitro cell counting, colony formation, migration and invasion assays were performed along with in vivo xenograft implantation and lung metastases experiments. The potential mechanisms involving target signal pathways were investigated by RNA-sequencing. Results PR55α expression level was suppressed in HCC tissues in comparison to healthy liver samples. Decreased PR55α levels were correlated with poorer prognosis (P = 0.0059). Knockdown of PR55α significantly promoted cell proliferation and migration, induced repression of the cell cycle progression and apoptosis in vitro while accelerating in vivo HCC growth and metastasis. Mechanistic analysis indicated that PR55α silencing was involved with MAPK/AKT signal pathway activation and resulted in increased phosphorylation of both AKT and ERK1/2. Conclusions This study identifies PR55α to be a candidate novel therapeutic target in the treatment of HCC.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xuejie Gao ◽  
Bo Li ◽  
Anqi Ye ◽  
Houcai Wang ◽  
Yongsheng Xie ◽  
...  

Abstract Background Multiple myeloma (MM) is a highly aggressive and incurable clonal plasma cell disease with a high rate of recurrence. Thus, the development of new therapies is urgently needed. DCZ0805, a novel compound synthesized from osalmide and pterostilbene, has few observed side effects. In the current study, we intend to investigate the therapeutic effects of DCZ0805 in MM cells and elucidate the molecular mechanism underlying its anti-myeloma activity. Methods We used the Cell Counting Kit-8 assay, immunofluorescence staining, cell cycle assessment, apoptosis assay, western blot analysis, dual-luciferase reporter assay and a tumor xenograft mouse model to investigate the effect of DCZ0805 treatment both in vivo and in vitro. Results The results showed that DCZ0805 treatment arrested the cell at the G0/G1 phase and suppressed MM cells survival by inducing apoptosis via extrinsic and intrinsic pathways. DCZ0805 suppressed the NF-κB signaling pathway activation, which may have contributed to the inhibition of cell proliferation. DCZ0805 treatment remarkably reduced the tumor burden in the immunocompromised xenograft mouse model, with no obvious toxicity observed. Conclusion The findings of this study indicate that DCZ0805 can serve as a novel therapeutic agent for the treatment of MM.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Zetao Chen ◽  
Yihong Chen ◽  
Yan Li ◽  
Weidong Lian ◽  
Kehong Zheng ◽  
...  

AbstractGlioma is one of the most lethal cancers with highly vascularized networks and growing evidences have identified glioma stem cells (GSCs) to account for excessive angiogenesis in glioma. Aberrant expression of paired-related homeobox1 (Prrx1) has been functionally associated with cancer stem cells including GSCs. In this study, Prrx1 was found to be markedly upregulated in glioma specimens and elevated Prrx1 expression was inversely correlated with prognosis of glioma patients. Prrx1 potentiated stemness acquisition in non-stem tumor cells (NSTCs) and stemness maintenance in GSCs, accompanied with increased expression of stemness markers such as SOX2. Prrx1 also promoted glioma angiogenesis by upregulating proangiogenic factors such as VEGF. Consistently, silencing Prrx1 markedly inhibited glioma proliferation, stemness, and angiogenesis in vivo. Using a combination of subcellular proteomics and in vitro analyses, we revealed that Prrx1 directly bound to the promoter regions of TGF-β1 gene, upregulated TGF-β1 expression, and ultimately activated the TGF-β/smad pathway. Silencing TGF-β1 mitigated the malignant behaviors induced by Prrx1. Activation of this pathway cooperates with Prrx1 to upregulate the expression of stemness-related genes and proangiogenic factors. In summary, our findings revealed that Prrx1/TGF-β/smad signal axis exerted a critical role in glioma stemness and angiogeneis. Disrupting the function of this signal axis might represent a new therapeutic strategy in glioma patients.


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