scholarly journals Bioactive glasses and electrospun composites that release cobalt to stimulate the HIF pathway for wound healing applications

2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Anu K. Solanki ◽  
Ferdinand V. Lali ◽  
Hélène Autefage ◽  
Shweta Agarwal ◽  
Amy Nommeots-Nomm ◽  
...  
Keyword(s):  
Wound Healing ◽  
Bioactive Glass ◽  
Hypoxia Inducible Factor ◽  
Magnesium Content ◽  
Ion Release ◽  
Bioactive Glasses ◽  
Covalent Bonds ◽  
Cobalt Ions ◽  
Hif Pathway ◽  
Glass Compositions

Abstract Background Bioactive glasses are traditionally associated with bonding to bone through a hydroxycarbonate apatite (HCA) surface layer but the release of active ions is more important for bone regeneration. They are now being used to deliver ions for soft tissue applications, particularly wound healing. Cobalt is known to simulate hypoxia and provoke angiogenesis. The aim here was to develop new bioactive glass compositions designed to be scaffold materials to locally deliver pro-angiogenic cobalt ions, at a controlled rate, without forming an HCA layer, for wound healing applications. Methods New melt-derived bioactive glass compositions were designed that had the same network connectivity (mean number of bridging covalent bonds between silica tetrahedra), and therefore similar biodegradation rate, as the original 45S5 Bioglass. The amount of magnesium and cobalt in the glass was varied, with the aim of reducing or removing calcium and phosphate from the compositions. Electrospun poly(ε-caprolactone)/bioactive glass composites were also produced. Glasses were tested for ion release in dissolution studies and their influence on Hypoxia-Inducible Factor 1-alpha (HIF-1α) and expression of Vascular Endothelial Growth Factor (VEGF) from fibroblast cells was investigated. Results Dissolution tests showed the silica rich layer differed depending on the amount of MgO in the glass, which influenced the delivery of cobalt. The electrospun composites delivered a more sustained ion release relative to glass particles alone. Exposing fibroblasts to conditioned media from these composites did not cause a detrimental effect on metabolic activity but glasses containing cobalt did stabilise HIF-1α and provoked a significantly higher expression of VEGF (not seen in Co-free controls). Conclusions The composite fibres containing new bioactive glass compositions delivered cobalt ions at a sustained rate, which could be mediated by the magnesium content of the glass. The dissolution products stabilised HIF-1α and provoked a significantly higher expression of VEGF, suggesting the composites activated the HIF pathway to stimulate angiogenesis.

scholarly journals A thermodynamic discourse on the dissolution behavior of bioactive glasses

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Barbara Pföss ◽  
Reinhard Conradt
Keyword(s):  
Bioactive Glass ◽  
Body Fluid ◽  
Solid Material ◽  
Aqueous System ◽  
Dissolution Behavior ◽  
Glassy Material ◽  
Bioactive Glasses ◽  
Gibbs Energies ◽  
The Impact ◽  
Glass Compositions

AbstractThe interaction between bioactive glass and body fluid is crucial for the special properties of this material, therefore a large number of experimental data is available in literature. However, a frame for systematic interpretation of these results in terms of understanding the mechanisms at the interface between glass and body medium and the relation between glass composition and dissolution behavior is still missing. For two multicomponent bioactive glasses, 45S5 and 13-93, the Gibbs energies of the glassy material on one side and their aqueous system on the other side were calculated individually. The difference between solid material and aqueous system further constitutes the pH dependent Gibbs energy of hydration, ∆Ghydr. The impact of glass compositions and glassy or crystalline state on ∆Ghydr is demonstrated referring to chemical durability. Along considerations regarding the aqueous system, the thermodynamic calculations proof the precipitation of hydroxyapatite inwater and simulated body fluid for a systemcontaining P2O5 and Ca2+. In the course of deriving the Gibbs energies for bioactive glass compositions via constitutional compounds, bioactive behavior is discussed from the point of coexisting equilibrium phases in the system of Na2O-CaO-SiO2.

scholarly journals A New Generation of Electrospun Fibers Containing Bioactive Glass Particles for Wound Healing

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5651
Author(s):  
Rachele Sergi ◽  
Valeria Cannillo ◽  
Aldo R. Boccaccini ◽  
Liliana Liverani
Keyword(s):  
Mechanical Properties ◽  
Wound Healing ◽  
Bioactive Glass ◽  
Flexible Structures ◽  
Biological Properties ◽  
Cellular Viability ◽  
Bioactive Glasses ◽  
Electrospinning Technique ◽  
Potential Applications ◽  
Biological Performance

Chitosan fibers blended with polyethylene oxide (CHIT_PEO) and crosslinked with genipin were fabricated by electrospinning technique. Subsequently, CHIT_PEO bioactive glass composite electrospun mats were fabricated with the aim to achieve flexible structures with adequate mechanical properties and improved biological performance respect to CHIT_PEO fibers, for potential applications in wound healing. Three different compositions of bioactive glasses (BG) were selected and investigated: 45S5 BG, a Sr and Mg containing bioactive glass (BGMS10) and a Zn-containing bioactive glass (BGMS_2Zn). Particulate BGs (particles size < 20 μm) were separately added to the starting CHIT_PEO solution before electrospinning. The two recently developed bioactive glasses (BGMS10 and BGMS_2Zn) showed very promising biological properties in terms of bioactivity and cellular viability; thus, such compositions were added for the first time to CHIT_PEO solution to fabricate composite electrospun mats. The incorporation of bioactive glass particles and their distribution into CHIT_PEO fibers were assessed by SEM and FTIR analyses. Furthermore, CHIT_PEO composite electrospun mats showed improved mechanical properties in terms of Young’s Modulus compared to neat CHIT_PEO fibers; on the contrary, the values of tensile strain at break (%) were comparable. Biological performance in terms of cellular viability was investigated by means of WST-8 assay and CHIT_PEO composite electrospun mats showed cytocompatibility and the desired cellular viability.

Bioactive Glasses: A Promising Therapeutic Ion Release Strategy for Enhancing Wound Healing

2020 ◽  
Vol 6 (10) ◽  
pp. 5399-5430
Author(s):  
Tina Mehrabi ◽  
Abdorreza S. Mesgar ◽  
Zahra Mohammadi
Keyword(s):  
Wound Healing ◽  
Ion Release ◽  
Bioactive Glasses ◽  
Release Strategy

scholarly journals The Influence of Na and Ti on theIn VitroDegradation and Bioactivity in 58S Sol-Gel Bioactive Glass

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Shirong Ni ◽  
Ruilin Du ◽  
Siyu Ni
Keyword(s):  
Activation Energy ◽  
Bioactive Glass ◽  
Body Fluid ◽  
Sol Gel ◽  
Apatite Formation ◽  
Ion Release ◽  
Buffer Solution ◽  
Bioactive Glasses ◽  
Initial Stage

The aim of this study was to investigate the effect of Na and Ti on thein vitrodegradation and bioactivity in the 58S bioactive glass. The degradation was evaluated through the activation energy of Si ion release from bioactive glasses and the weight loss of bioactive glasses in Tris-HCl buffer solution. Thein vitrobioactivity of the bioactive glasses was investigated by analysis of apatite-formation ability in the simulated body fluid (SBF). The results showed that Na in the 58S glass accelerated the dissolution rate of the glass, whereas Ti in the 58S glass slowed down the rate of glass solubility. Bioactivity tests showed that Na in glass increased the apatite-forming ability in SBF. In contrast, Ti in glass retards the apatite formation at the initial stage of SBF soaking but does not affect the growth of apatite after long periods of soaking.

scholarly journals The Effect of Bioactive Glass-Enhanced Orthodontic Bonding Resins on Prevention of Demineralization: A Systematic Review

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2495 ◽  
Author(s):  
Abdulaziz Alamri ◽  
Zainah Salloot ◽  
Alaa Alshaia ◽  
Maria Salem Ibrahim
Keyword(s):  
Bioactive Glass ◽  
Polarized Light ◽  
Inclusion Criteria ◽  
Micro Computed Tomography ◽  
Ion Release ◽  
Bioactive Glasses ◽  
Standardized Protocol ◽  
Proportional Relationship ◽  
Orthodontic Bonding

At present, bioactive glasses (BAGs) are demonstrating promising results in the remineralization of hard tissues. Their bioactive properties can potentially overcome the demineralization effect accompanying orthodontic treatment. This review aimed to evaluate the effectiveness of bioactive glass enhanced orthodontic bonding resins on enamel remineralization, in addition to their antibacterial, ion release and acid neutralization effect. Four databases (PubMed, MEDLINE, Web of Science and Scopus) were searched. Two hundred and fifty-one full-text articles were screened independently, out of which seven studies satisfied the inclusion criteria. Quality appraisal was performed by two independent reviewers. Methodologies used to assess the anti-demineralization effect included Micro-Computed Tomography, Polarized Light Microscopy and Hardness Testing (Knoop and Berkovich). All seven articles confirmed the superior remineralization effect of BAG orthodontic bonding resins compared to their non-BAG counterparts. A proportional relationship was proved between BAG concentrations and increased anti-demineralization effect. The addition of antibacterial agents to BAG does not necessarily improve its anti-demineralization effect. Although studies have confirmed the effectiveness of BAG orthodontic bonding resins on enamel remineralization, there was a degree of heterogeneity across studies due to the lack of an in vitro studies standardized protocol.

scholarly journals Incorporation of Novel Elements in Bioactive Glass Compositions to Enhance Implant Performance

2021 ◽  
Author(s):  
Joy-anne N. Oliver ◽  
Olanrewaju Akande ◽  
Melanie Ecker
Keyword(s):  
Cell Proliferation ◽  
Bioactive Glass ◽  
Bacterial Infections ◽  
Glass Composition ◽  
Medical Applications ◽  
The Novel ◽  
Bioactive Glasses ◽  
Overall Performance ◽  
A Site ◽  
Glass Compositions

Increasing popularities of bioactive-glasses and their potential medical applications have led to countless studies into improving their material characteristics and overall performance. Some scientists hope to create new bioactive-glass compositions, while others seek to merely modify existing ones such as the novel 45S5 bioactive-glass composition; created by Dr. Larry Hench. These modifications aim to address potential complications that may arise at a site following implantation such as bacterial infections. In other cases, the incorporation of a selected element or compound may aim to improve the implant functioning by increasing cell proliferation. Although possibilities are plentiful, researchers avoid compromising the typical bioactive glass characteristics when doping with elements such as silver, or gold to achieve additional properties. This chapter elaborates on the incorporation of popular elements by doping bioactive-glass compositions to introduce desired properties based on the implant application.

Preparation and in vitro evaluation of Lithium-doped bioactive glasses for wound healing with nerve repair potential

2021 ◽  
Vol 292 ◽  
pp. 129629
Author(s):  
Rong Wei ◽  
Zhaowenbin Zhang ◽  
Min Xing ◽  
Yanling Zhou ◽  
Jiang Chang
Keyword(s):  
Wound Healing ◽  
Nerve Repair ◽  
Bioactive Glasses ◽  
In Vitro Evaluation

scholarly journals A small molecule HIF-1α stabilizer that accelerates diabetic wound healing

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guodong Li ◽  
Chung-Nga Ko ◽  
Dan Li ◽  
Chao Yang ◽  
Wanhe Wang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Small Molecule ◽  
Hypoxia Inducible Factor ◽  
Diabetic Patients ◽  
Diabetic Mice ◽  
Impaired Wound Healing ◽  
Von Hippel Lindau ◽  
Design And Synthesis

AbstractImpaired wound healing and ulcer complications are a leading cause of death in diabetic patients. In this study, we report the design and synthesis of a cyclometalated iridium(III) metal complex 1a as a stabilizer of hypoxia-inducible factor-1α (HIF-1α). In vitro biophysical and cellular analyses demonstrate that this compound binds to Von Hippel-Lindau (VHL) and inhibits the VHL–HIF-1α interaction. Furthermore, the compound accumulates HIF-1α levels in cellulo and activates HIF-1α mediated gene expression, including VEGF, GLUT1, and EPO. In in vivo mouse models, the compound significantly accelerates wound closure in both normal and diabetic mice, with a greater effect being observed in the diabetic group. We also demonstrate that HIF-1α driven genes related to wound healing (i.e. HSP-90, VEGFR-1, SDF-1, SCF, and Tie-2) are increased in the wound tissue of 1a-treated diabetic mice (including, db/db, HFD/STZ and STZ models). Our study demonstrates a small molecule stabilizer of HIF-1α as a promising therapeutic agent for wound healing, and, more importantly, validates the feasibility of treating diabetic wounds by blocking the VHL and HIF-1α interaction.

scholarly journals Hypoxia-Inducible Factor 2a Expression Is Positively Correlated With Gleason Score in Prostate Cancer

2021 ◽  
Vol 20 ◽  
pp. 153303382199001
Author(s):  
Dimitrios Pavlakis ◽  
Spyridon Kampantais ◽  
Konstantinos Gkagkalidis ◽  
Victoras Gourvas ◽  
Dimitrios Memmos ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Gleason Score ◽  
Locally Advanced ◽  
Hypoxia Inducible Factor ◽  
Immunohistochemical Expression ◽  
Locally Advanced Prostate Cancer ◽  
Grade Group ◽  
Main Factors ◽  
Hif Pathway ◽  
Lower Expression

Background: One of the main factors in response to hypoxia in the tumor microenvironment is the hypoxia-inducible factor (HIF) pathway. Although its role in other solid tumors, particularly renal cell carcinoma, has been sufficiently elucidated, it remains elusive in prostate cancer. The aim of the present study was to investigate the expression of main proteins involved in this pathway and determine the correlation of the results with clinicopathological outcomes of patients with prostate cancer. Methods: The immunohistochemical expression of HIF-1a, HIF-2a and their regulators, prolyl hydroxylase domain (PHD)1, PHD2 and PHD3 and factor inhibiting HIF (FIH), was assessed on a tissue microarray. This was constructed from radical prostatectomy specimens, involving both tumor and corresponding adjacent non-tumoral prostate tissues from 50 patients with localized or locally advanced prostate cancer. Results: In comparison with non-tumoral adjacent tissue, HIF-1a exhibited an equal or lower expression in 86% of the specimens (P = 0.017), while HIF-2a was overexpressed in 52% (P = 0.032) of the cases. HIF-1a protein expression was correlated with HIF-2a (P < 0.001), FIH (P = 0.004), PHD1 (P < 0.001), PHD2 (P < 0.001) and PHD3 (P = 0.035). HIF-2a expression was positively correlated with Gleason score (P = 0.017) and International Society of Urological Pathologists (ISUP) grade group (P = 0.022). Conclusions: The findings of the present study suggest a key role for HIF-2a in prostate cancer, as HIF-2a expression was found to be correlated with Gleason score and ISUP grade of the patients. However, further studies are required to validate these results and investigate the potential value of HIF-2a as a therapeutic target in prostate cancer.

Study of the Bioactive Behavior of Thermally Treated Modified 58S Bioactive Glass

2008 ◽  
Vol 396-398 ◽  
pp. 131-134 ◽  
Author(s):  
Ourania Menti Goudouri ◽  
Xanthippi Chatzistavrou ◽  
Eleana Kontonasaki ◽  
Nikolaos Kantiranis ◽  
Lambrini Papadopoulou ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Bioactive Glass ◽  
Sol Gel ◽  
Bioactive Glasses ◽  
X Ray ◽  
Characteristic Temperatures ◽  
Calcium Silicates ◽  
Crystal Phases ◽  
Thermally Treated

Thermal treatment of bioactive glasses can affect their microstructure and thus their bioactivity. The aim of this study was the characterization of the thermally treated sol-gel-derived bioactive glass 58S at characteristic temperatures and the dependence of its bioactive behavior on the specific thermal treatment. The thermal behavior of the bioactive glass was studied by thermal analysis (TG/DTA). Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffractometry (XRD) were used for the characterization of the bioactive glass. The bioactive behavior in Simulated Body Fluid (SBF) was examined by Scanning Electron Microscopy (SEM-EDS) and FTIR. The major crystal phases after thermal treatment were Calcium Silicates, Wollastonite and Pseudowollastonite, while all thermally treated samples developed apatite after 48 hours in SBF. A slight enhancement of bioactivity was observed for the samples heated at the temperature range 910-970oC.

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