scholarly journals PCL-Coated Multi-Substituted Calcium Phosphate Bone Scaffolds with Enhanced Properties

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4403
Author(s):  
Leonard Bauer ◽  
Maja Antunović ◽  
Gloria Gallego-Ferrer ◽  
Marica Ivanković ◽  
Hrvoje Ivanković
Keyword(s):  
Calcium Phosphate ◽  
Positive Impact ◽  
Early Stage ◽  
Quantitative Polymerase Chain Reaction ◽  
Human Mesenchymal Stem Cells ◽  
Magnesium Content ◽  
Vacuum Impregnation ◽  
Type I ◽  
Strontium Nitrate ◽  
Compression Tests

Ionic substitutions within the hydroxyapatite lattice are a widely used approach to mimic the chemical composition of the bone mineral. In this work, Sr-substituted and Mg- and Sr-co-substituted calcium phosphate (CaP) scaffolds, with various levels of strontium and magnesium substitution, were prepared using the hydrothermal method at 200 °C. Calcium carbonate skeletons of cuttlefish bone, ammonium dihydrogenphosphate (NH4H2PO4), strontium nitrate (Sr(NO3)2), and magnesium perchlorate (Mg(ClO4)2) were used as reagents. Materials were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Whole powder pattern decomposition refinements of XRD data indicated that increased magnesium content in the Mg- and Sr-co-substituted scaffolds was related to an increased proportion of the whitlockite (WH) phase in the biphasic hydroxyapatite (HAp)/WH scaffolds. In addition, refinements indicate that Sr2+ ions have replaced Ca2+ sites in the WH phase. Furthermore, PCL-coated Mg-substituted and Sr- and Mg-co-substituted scaffolds, with the HAp:WH wt. ratio of 90:10 were prepared by vacuum impregnation. Results of compression tests showed a positive impact of the WH phase and PCL coating on the mechanical properties of scaffolds. Human mesenchymal stem cells (hMSCs) were cultured on composite scaffolds in an osteogenic medium for 21 days. Immunohistochemical staining showed that Mg-Sr-CaP/PCL scaffold exhibited higher expression of collagen type I than the Mg-CaP/PCL scaffold, indicating the positive effect of Sr2+ ions on the differentiation of hMSCs, in concordance with histology results. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis confirmed an early stage of osteogenic differentiation.

Gene Expressions Induced by Calcium Phosphate Ceramics after Implantation into the Muscle of Rat

2005 ◽  
Vol 475-479 ◽  
pp. 2363-2366
Author(s):  
Jin Rui Xu ◽  
Hong Song Fan ◽  
Yan Fei Tan ◽  
Xing Dong Zhang
Keyword(s):  
Calcium Phosphate ◽  
Collagen Type ◽  
Early Stage ◽  
Collagen Type I ◽  
Type I ◽  
Rt Pcr ◽  
Gene Expressions ◽  
Porous Hydroxyapatite ◽  
Calcium Phosphate Ceramics

The osteoinductivity of calcium phosphate ceramics has been studied extensively, but the mechanism is still unclear and few reports about the molecular mechanism in the osteoinductive process. In this study the osteoblast related gene expressions induced by biomaterials were investigated by isolating the RNA from the tissue grown in porous hydroxyapatite/tricalcium phosphate (HA/TCP) ceramics implanted in rat femur muscle on day 7, 15, 30, 60, 90,120, and analyzed by RT-PCR technique. RNA extracted from muscle without implant was used as control at the same time. The results showed that osteopontin and osteocalcin genes, the important osteoblastic markers, expressed in early stage, on day 7 after implantation, and were detected at any period. Collagen type I gene expressed on day 60, 90 and 120. It revealed that osteoblast differentiation occurred very early before collagen type I expression after implanting HA/TCP ceramics in vivo.

scholarly journals The preparation and application of calcium phosphate biomedical composites in filling of weight-bearing bone defects

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lijia Cheng ◽  
Tianchang Lin ◽  
Ahmad Taha Khalaf ◽  
Yamei Zhang ◽  
Hongyan He ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Weight Bearing ◽  
Bone Defects ◽  
Type I ◽  
Artificial Bone ◽  
Thermosensitive Hydrogel ◽  
Bone Repairing ◽  
Histological Staining

AbstractNowadays, artificial bone materials have been widely applied in the filling of non-weight bearing bone defects, but scarcely ever in weight-bearing bone defects. This study aims to develop an artificial bone with excellent mechanical properties and good osteogenic capability. Firstly, the collagen-thermosensitive hydrogel-calcium phosphate (CTC) composites were prepared as follows: dissolving thermosensitive hydrogel at 4 °C, then mixing with type I collagen as well as tricalcium phosphate (CaP) powder, and moulding the composites at 37 °C. Next, the CTC composites were subjected to evaluate for their chemical composition, micro morphology, pore size, Shore durometer, porosity and water absorption ability. Following this, the CTC composites were implanted into the muscle of mice while the 70% hydroxyapatite/30% β-tricalcium phosphate (HA/TCP) biomaterials were set as the control group; 8 weeks later, the osteoinductive abilities of biomaterials were detected by histological staining. Finally, the CTC and HA/TCP biomaterials were used to fill the large segments of tibia defects in mice. The bone repairing and load-bearing abilities of materials were evaluated by histological staining, X-ray and micro-CT at week 8. Both the CTC and HA/TCP biomaterials could induce ectopic bone formation in mice; however, the CTC composites tended to produce larger areas of bone and bone marrow tissues than HA/TCP. Simultaneously, bone-repairing experiments showed that HA/TCP biomaterials were easily crushed or pushed out by new bone growth as the material has a poor hardness. In comparison, the CTC composites could be replaced gradually by newly formed bone and repair larger segments of bone defects. The CTC composites trialled in this study have better mechanical properties, osteoinductivity and weight-bearing capacity than HA/TCP. The CTC composites provide an experimental foundation for the synthesis of artificial bone and a new option for orthopedic patients.

scholarly journals Mineralization of Titanium Surfaces: Biomimetic Implants

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2879
Author(s):  
Javier Gil ◽  
Jose Maria Manero ◽  
Elisa Ruperez ◽  
Eugenio Velasco-Ortega ◽  
Alvaro Jiménez-Guerra ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Dental Implants ◽  
Early Stage ◽  
Calcium Phosphates ◽  
Biological Fixation ◽  
Biomimetic Surfaces ◽  
Titanium Surfaces ◽  
Deposition Processes ◽  
Fast Dissolution ◽  
Plasma Sprayed

The surface modification by the formation of apatitic compounds, such as hydroxyapatite, improves biological fixation implants at an early stage after implantation. The structure, which is identical to mineral content of human bone, has the potential to be osteoinductive and/or osteoconductive materials. These calcium phosphates provoke the action of the cell signals that interact with the surface after implantation in order to quickly regenerate bone in contact with dental implants with mineral coating. A new generation of calcium phosphate coatings applied on the titanium surfaces of dental implants using laser, plasma-sprayed, laser-ablation, or electrochemical deposition processes produces that response. However, these modifications produce failures and bad responses in long-term behavior. Calcium phosphates films result in heterogeneous degradation due to the lack of crystallinity of the phosphates with a fast dissolution; conversely, the film presents cracks, which produce fractures in the coating. New thermochemical treatments have been developed to obtain biomimetic surfaces with calcium phosphate compounds that overcome the aforementioned problems. Among them, the chemical modification using biomineralization treatments has been extended to other materials, including composites, bioceramics, biopolymers, peptides, organic molecules, and other metallic materials, showing the potential for growing a calcium phosphate layer under biomimetic conditions.

scholarly journals Proteomic and genomic analysis of acid dentin lysate with focus on TGF-β signaling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jila Nasirzade ◽  
Zahra Kargarpour ◽  
Goran Mitulović ◽  
Franz Josef Strauss ◽  
Layla Panahipour ◽  
...  
Keyword(s):  
Cellular Response ◽  
Alveolar Bone ◽  
Quantitative Polymerase Chain Reaction ◽  
Genomic Analysis ◽  
Type I ◽  
Gingival Fibroblasts ◽  
Nadph Oxidase 4 ◽  
Major Response ◽  
Collagen Membranes ◽  
Β Receptor

AbstractParticulate autologous tooth roots are increasingly used for alveolar bone augmentation; however, the proteomic profile of acid dentin lysate and the respective cellular response have not been investigated. Here we show that TGF-β1 is among the 226 proteins of acid dentin lysate (ADL) prepared from porcine teeth. RNA sequencing identified 231 strongly regulated genes when gingival fibroblasts were exposed to ADL. Out of these genes, about one third required activation of the TGF-β receptor type I kinase including interleukin 11 (IL11) and NADPH oxidase 4 (NOX4). Reverse transcription-quantitative polymerase chain reaction and immunoassay confirmed the TGF-β-dependent expression of IL11 and NOX4. The activation of canonical TGF-β signaling by ADL was further confirmed by the phosphorylation of Smad3 and translocation of Smad2/3, using Western blot and immunofluorescence staining, respectively. Finally, we showed that TGF-β activity released from dentin by acid lysis adsorbs to titanium and collagen membranes. These findings suggest that dentin particles are a rich source of TGF-β causing a major response of gingival fibroblasts.

scholarly journals Micafungin Inhibits Dengue Virus Infection through the Disruption of Virus Binding, Entry, and Stability

2021 ◽  
Vol 14 (4) ◽  
pp. 338
Author(s):  
Yen-Chen Chen ◽  
Jeng-Wei Lu ◽  
Chia-Tsui Yeh ◽  
Te-Yu Lin ◽  
Feng-Cheng Liu ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Dengue Fever ◽  
Early Stage ◽  
Quantitative Polymerase Chain Reaction ◽  
Enterovirus 71 ◽  
Denv Infection ◽  
Immunofluorescence Assay ◽  
Dependent Manner ◽  
Virus Binding ◽  
Virus Serotype

Dengue fever is an arbovirus disease caused by infection with the dengue virus (DENV). Half of the world’s population lives under the threat of dengue fever, however, researchers have yet to develop any drugs that are clinically applicable to this infection. Micafungin is a member of the echinocandins family of anti-fungal drugs, capable of blocking the synthesis of β-1,3-D-glucan in the walls of fungal cells. Previous studies have demonstrated the effectiveness of Micafungin against infections of enterovirus 71 (EV71) and chikungunya virus (CHIKV). This is the first study demonstrating the effectiveness of micafungin in inhibiting the cytopathic effects of dengue virus serotype 2 (DENV-2) in a dose-dependent manner. Time-of-addition assays verified the inhibitory effects of micafungin in pre-treated, co-treated, and full-treatment groups. Binding and entry assays also demonstrated the effectiveness of micafungin in the early stage of DENV-2 infection. The virucidal efficacy of micafungin appears to lie in its ability to destroy the virion. Molecular docking assays revealed the binding of micafungin to the envelope protein of DENV-2, thereby revealing the mechanism by which micafungin affects the early stage of DENV infection and the stability of DENV. Two other micafungin analogs, caspofungin and anidulafungin, were also shown to have the antiviral effects on DENV-2. Finally, immunofluorescence assay (IFA) and reverse-transcription quantitative polymerase chain reaction (RT-qPCR) confirmed the broad anti-DENV ability of micafungin against dengue virus serotypes 1, 3, and 4 (DENV-1, DENV-3, and DENV-4). Taken together, these results demonstrate the potential of micafungin and its analogs as candidates for the development of broad-spectrum treatments for DENV infection.

scholarly journals Early-stage macroporosity enhancement in calcium phosphate cements by inclusion of poly(N-vinylpyrrolidone) particles as a porogen

2020 ◽  
Vol 23 ◽  
pp. 100901 ◽  
Author(s):  
Irene Lodoso-Torrecilla ◽  
Floris Stumpel ◽  
John A. Jansen ◽  
Jeroen J.J.P. van den Beucken
Keyword(s):  
Calcium Phosphate ◽  
Early Stage ◽  
Calcium Phosphate Cements

Expression of Cannabinoid Receptors in Myometrium and its Correlation With Dysmenorrhea in Adenomyosis

2019 ◽  
Vol 26 (12) ◽  
pp. 1618-1625 ◽  
Author(s):  
Xue Shen ◽  
Hua Duan ◽  
Sha Wang ◽  
Wei Hong ◽  
Yu-Yan Wang ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Cannabinoid Receptors ◽  
Pain Perception ◽  
Cannabinoid Receptor ◽  
Quantitative Polymerase Chain Reaction ◽  
Premenopausal Women ◽  
Type I ◽  
Junctional Zone ◽  
Tissue Samples ◽  
Expression Levels

The myometrium, especially the junctional zone (JZ), is now well documented to have a role in the pathogenesis of adenomyosis. Cannabinoid receptors have been shown to participate in the establishment of endometriosis and its pain perception. However, its relation to adenomyosis has not been identified yet. The aim of this study was to investigate the expression of cannabinoid receptor type I (CB1) and type II (CB2) in myometrium of uteri with and without adenomyosis and determine the correlation between their levels and clinical parameters of adenomyosis. We collected tissue samples of JZ and the outer myometrium from 45 premenopausal women with adenomyosis and 34 women without adenomyosis. CB1 and CB2 messenger RNA (mRNA) and protein expression levels were evaluated by the use of Western blotting and real-time quantitative polymerase chain reaction from all samples. Clinical information on the severity of dysmenorrhea and other data were collected. We found both CB1 and CB2 mRNA and protein levels in women with adenomyosis were significantly higher than those of controls, and CB1 expression levels in JZ were positively correlated with the severity of dysmenorrhea. These data suggest that cannabinoid receptor CB1 may be involved in the pathogenesis of dysmenorrhea in adenomyosis and may be a potential therapeutic target.

Calcium phosphate-based particles influence osteogenic maturation of human mesenchymal stem cells

2009 ◽  
Vol 5 (4) ◽  
pp. 1294-1305 ◽  
Author(s):  
L. Saldaña ◽  
S. Sánchez-Salcedo ◽  
I. Izquierdo-Barba ◽  
F. Bensiamar ◽  
L. Munuera ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Calcium Phosphate ◽  
Human Mesenchymal Stem Cells

scholarly journals Lymphocytes are detrimental during the early innate immune response against Listeria monocytogenes

2006 ◽  
Vol 203 (4) ◽  
pp. 933-940 ◽  
Author(s):  
Javier A. Carrero ◽  
Boris Calderon ◽  
Emil R. Unanue
Keyword(s):  
Immune Response ◽  
Listeria Monocytogenes ◽  
Innate Immune Response ◽  
Early Stage ◽  
Bacterial Pathogen ◽  
Interleukin 10 ◽  
Innate Immune ◽  
Type I ◽  
Phagocytic Cells ◽  
Immunodeficient Mice

Mice deficient in lymphocytes are more resistant than normal mice to Listeria monocytogenes infection during the early innate immune response. This paradox remains unresolved: lymphocytes are required for sterilizing immunity, but their presence during the early stage of the infection is not an asset and may even be detrimental. We found that lymphocyte-deficient mice, which showed limited apoptosis in infected organs, were resistant during the first four days of infection but became susceptible when engrafted with lymphocytes. Engraftment with lymphocytes from type I interferon receptor–deficient (IFN-αβR−/−) mice, which had reduced apoptosis, did not confer increased susceptibility to infection, even when the phagocytes were IFN-αβR+/+. The attenuation of innate immunity was due, in part, to the production of the antiinflammatory cytokine interleukin 10 by phagocytic cells after the apoptotic phase of the infection. Thus, immunodeficient mice were more resistant relative to normal mice because the latter went through a stage of lymphocyte apoptosis that was detrimental to the innate immune response. This is an example of a bacterial pathogen creating a cascade of events that leads to a permissive infective niche early during infection.

scholarly journals Can Financial Economics Cure Cancer?

2021 ◽  
Author(s):  
Andrew W. Lo
Keyword(s):  
High Throughput Screening ◽  
Business Models ◽  
Positive Impact ◽  
Early Stage ◽  
Genome Project ◽  
Gene Therapies ◽  
Biomedical Innovation ◽  
New Business ◽  
The Cost ◽  
The Human Genome Project

AbstractFunding for early-stage biomedical innovation has become more difficult to secure at the same time that medical breakthroughs seem to be occurring at ever increasing rates. One explanation for this counterintuitive trend is that increasing scientific knowledge can actually lead to greater economic risk for investors in the life sciences. While the Human Genome Project, high-throughput screening, genetic biomarkers, immunotherapies, and gene therapies have made a tremendously positive impact on biomedical research and, consequently, patient lives, they have also increased the cost and complexity of the drug development process, causing many investors to shift their assets to more attractive investment opportunities. This suggests that new business models and financing strategies can be used to reduce the risk and increase the attractiveness of biomedical innovation so as to bring new and better therapies to patients faster.

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