Spinning of Endless Bioactive Silicate Glass Fibres for Fibre Reinforcement Applications

Bioactive glasses have been used for many years in the human body as bone substitute. Since bioactive glasses are not readily available in the form of endless thin fibres with diameters below 20 µm, their use is limited to mainly non-load-bearing applications in the form of particles or granules. In this study, the spinnability of four bioactive silicate glasses was evaluated in terms of crystallisation behaviour, characteristic processing temperatures and viscosity determined by thermal analysis. The glass melts were drawn into fibres and their mechanical strength was measured by single fibre tensile tests before and after the surface treatment with different silanes. The degradation of the bioactive glasses was observed in simulated body fluid and pure water by recording the changes of the pH value and the ion concentration by inductively coupled plasma optical emission spectrometry; further, the glass degradation process was monitored by scanning electron microscopy. Additionally, first in vitro experiments using murine pre-osteoblast cell line MC3T3E1 were carried out in order to evaluate the interaction with the glass fibre surface. The results achieved in this work show up the potential of the manufacturing of endless bioactive glass fibres with appropriate mechanical strength to be applied as reinforcing fibres in new innovative medical implants.

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Acid-free Hydrothermal Process for Synthesis of Bioactive Glasses 70SiO2–(30-x)CaO–xZnO (x = 1, 3, 5 mol.%)

Proceedings ◽

10.3390/proceedings2020062006 ◽

2020 ◽

Vol 62 (1) ◽

pp. 6

Author(s):

Ta Anh Tuan ◽

Elena V. Guseva ◽

Le Hong Phuc ◽

Nguyen Quan Hien ◽

Nguyen Viet Long ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Hydrothermal Process ◽

Optical Emission ◽

Emission Spectrometry ◽

Bioactive Glasses ◽

Vitro Experiment ◽

In Vitro Experiment ◽

Zn Addition ◽

Sbf Solution

Bioactive glasses 70SiO2–(30-x)CaO–xZnO (x = 1, 3, 5 mol.%) were prepared by the acid-free hydrothermal method in keeping with green chemical technology. The synthetic glasses were investigated by TG-DSC, BET, XRD, and SEM–EDX methods. All synthetic glasses present mesoporous structures consisting of aggregates of nanoparticles. The bioactivity of synthetic glasses was confirmed through the formation of the hydroxyapatite phase after an in vitro experiment in simulated body fluid (SBF) solution. The effect of Zn addition is shown through the decrease in the bioactivity of synthetic glasses. Additionally, the inductively coupled plasma optical emission spectrometry (ICP-OES) analysis indicates that the Zn ions were released from the glassy networks during in vitro experiments, and they act as Zn(OH)2 suspended precipitation to inhibit the apatite deposition. The in vitro experiment in cell culture matter was performed for SaOS2 and Eahy929 cells. The results confirm the biocompatibility of synthetic glasses and the role of Zn addition in the proliferation of living cells.

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Release of metal ions from fixed orthodontic appliance: An in vitro study in continuous flow system

The Angle Orthodontist ◽

10.2319/113012-911.1 ◽

2013 ◽

Vol 84 (1) ◽

pp. 140-148 ◽

Cited By ~ 26

Author(s):

Marcin Mikulewicz ◽

Katarzyna Chojnacka ◽

Paulina Wołowiec

Keyword(s):

Metal Ions ◽

Metal Ion ◽

Ion Concentration ◽

Emission Spectrometry ◽

Orthodontic Appliances ◽

Orthodontic Appliance ◽

Toxic Dose ◽

Fixed Orthodontic Appliances ◽

Fixed Orthodontic Appliance

ABSTRACT Objective: To evaluate the release of metal ions from fixed orthodontic appliances. Materials and Methods: A new system for in vitro testing of dental materials was constructed and consisted of a thermostatic glass reactor that enabled immersion of the studied material. Experimental conditions reflected the human oral cavity, with a temperature of 37°C and a saliva flow rate of 0.5mL/min. The simulated fixed orthodontic appliance made of stainless steel was evaluated. Sampling was performed at several time points during the 28-day study, and the metal ion concentration was determined by inductively coupled plasma optical emission spectrometry. Results: The total mass of released metal ions from the appliance during 4 weeks of the experiment was as follows nickel 18.7 μg, chromium 5.47 μg, copper 31.3 μg. Conclusions: The estimated doses of nickel, chromium, and copper determined by extrapolation of experimental data released during the treatment period were far below the toxic dose to humans. This shows that orthodontic treatment might not be a significant source of exposure to these metal ions.

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In Vitro Evaluation of Biologically Derived Hydroxyapatite Coatings Manufactured by High Velocity Suspension Spraying

Journal of Thermal Spray Technology ◽

10.1007/s11666-021-01265-0 ◽

2021 ◽

Author(s):

M. Blum ◽

M. Sayed ◽

E. M. Mahmoud ◽

A. Killinger ◽

R. Gadow ◽

...

Keyword(s):

High Velocity ◽

Inductively Coupled Plasma ◽

Ph Value ◽

Low Cost ◽

Optical Emission ◽

Fish Bone ◽

Emission Spectrometry ◽

Slight Variation ◽

Flame Spray

AbstractThis investigation aims to study a novel biologically derived coating applied on Ti alloy substrates. Obtained from a low-cost fish bone resource, a nanocrystalline hydroxyapatite has been synthesized and converted to an organic suspension. Coating was then manufactured by a high-velocity suspension flame spray process. The microstructure, phase composition, coating thickness, and roughness of hydroxyapatite (HA)-coated samples were studied. The results indicated the presence of both hydroxyapatite and β-tricalcium phosphate phases and the final coating layer was uniform and dense. In vitro bioactivity and biodegradability of the HA/Ti composite samples were estimated by immersion in simulated body fluid. Remarkable reductions in Ca2+ and PO43− ion concentrations were observed as well as low weight loss percentage and a slight variation in the pH value, indicating the generation of an apatite layer on the surface of all studied samples. Scanning electron microscopy, energy-dispersive x-ray analysis, and inductively coupled plasma–optical emission spectrometry confirm these results. Thus biological derived HA coatings are a promising candidate to enhance bioactivity and biodegradability of bone implants. To demonstrate feasibility on commercial medical components, a medical screw was coated and evaluated.

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Rational Design and Fabrication of Biomimetic Hierarchical Scaffolds With Bone-Matchable Strength for Bone Regeneration

Frontiers in Materials ◽

10.3389/fmats.2020.622669 ◽

2021 ◽

Vol 7 ◽

Author(s):

Ruixian Lian ◽

Peng Xie ◽

Lan Xiao ◽

Zoya Iqbal ◽

Shihao Zhang ◽

...

Keyword(s):

Mechanical Properties ◽

Bone Regeneration ◽

Rational Design ◽

Ph Value ◽

Mesoporous Structure ◽

Degradation Process ◽

Bioactive Glasses ◽

Template Removal ◽

Clinical Level

The development of scaffolds with bone-mimicking compositions, hierarchical structure, and bone-matchable mechanical properties may offer a novel route for the achievement of effective bone regeneration. Although bioactive glasses have been widely utilized for bone regeneration at the clinical level, their brittleness and uncontrolled pore structure limit further applications. Herein, this study aims to develop a kind of bioactive scaffold with a macroporous/microporous/mesoporous structure via impregnating a sponge template with mesoporous bioactive glass (MBG) sol, followed by sponge template removal. In order to improve the mechanical properties and stability of the MBG scaffolds, desaminotyrosyl ethyl tyrosine polycarbonates (PDTEC), a biodegradable polymer which does not induce acid side-effects caused by conventional polylactide, was selected to decorate the resulting hierarchical scaffolds through a surface coating approach. The PDTEC functionalization endowed the scaffolds with improved mechanical strength matching the bearable range of trabecular bone (2–12 MPa). Meanwhile, the relative neutral pH value was maintained during their degradation process. In vitro studies demonstrated that the PDTEC accelerated the biomineralization of the scaffolds, and promoted the attachment and proliferation, holding high promise for bone regeneration.

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Bioactivity Behavior of YSZ-Al2O3/10HAP Bioceramics Composites in Simulated Body Fluid

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.980.13 ◽

2014 ◽

Vol 980 ◽

pp. 13-17

Author(s):

M.R.N. Liyana ◽

Nur Maizatul Shima Adzali ◽

M.Z.M. Zamzuri

Keyword(s):

Simulated Body Fluid ◽

Body Fluid ◽

Immersion Time ◽

Ph Value ◽

Dental Materials ◽

Biological Response ◽

Ion Concentration ◽

Human Blood Plasma ◽

Apatite Formation

Yttria-stabilized zirconia and alumina made significant contributions to the development of health care industry, specifically as orthopedic and dental materials. Both bioceramics are nearly inert ceramics, as they do not allow the interfacial bonding with tissue. Thus, it is necessary to provide bioactive surrounding as to elicit a specific biological response at the interface of material. This research reported the microstructure and bioactivity behavior of YSZ-Al2O3/10HAP with 30 wt. % and 60 wt. % of YSZ content. Powders were mixed before being compacted at 225MPa using uni-axial press machine. The composites were sintered at 1200 ̊C with heating rate of 10 ̊C/min. In-vitro bioactivity behavior of the composites were evaluated by immersing the composites into simulated body fluid. Results from x-ray diffraction pattern, confirmed the phase formation of apatite by the presence of Ca2P2O7, and CaO that might be useful on implant cell interaction in a body environment. The apatite formation was observed on the surfaces of the composites by SEM only after 9 days of immersion and subsequently apatite nucleation increased with prolonging immersion time. The dynamic changes in pH, between ion concentration in SBF and bioceramics surfaces correspondedwith an immersion time. Up to 30 days of immersion, the pH value of SBF stabilized approximately around pH 7.4-7.6, similar to the human blood plasma. Formation of apatite on composites surface of prepared YSZ-Al2O3/10HAP bioceramics may contribute to the improved biocompatibility and osteoconductivity.

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Rhenium-188 Labeled Hydroxyapatite and Rhenium-188 Sulfur Colloid

Nuklearmedizin ◽

10.1055/s-0038-1629737 ◽

1997 ◽

Vol 36 (02) ◽

pp. 71-75 ◽

Cited By ~ 6

Author(s):

S. Glatz ◽

S. N. Reske ◽

K. G. Grillenberger

Keyword(s):

Synovial Fluid ◽

Ph Value ◽

Surgical Removal ◽

Radiation Synovectomy ◽

Sulfur Colloid ◽

Target Organs ◽

Aseptic Conditions ◽

In Vitro Stability ◽

Potential Use

Summary Aim: One therapeutic approach to rheumatoid arthritis and other inflammatory arthropathies besides surgical removal of inflamed synovium is radiation synovectomy using beta-emitting radionuclides to destroy the affected synovial tissue. Up to now the major problem associated with the use of labeled particles or colloids has been considerable leakage of radionuclides from the injected joint coupled with high radiation doses to liver and other non target organs. In this study we compared 188Re labeled hydroxyapatite particles and 188Re rhenium sulfur colloid for their potential use in radiation synovectomy. Methods: To this end we varied the labeling conditions (concentrations, pH-value, heating procedure) and analyzed the labeling yield, radiochemical purity, and in vitro stability of the resulting radiopharmaceutical. Results: After optimizing labeling conditions we achieved a labeling yield of more than 80% for 188Re hydroxyapatite and more than 90% for the rhenium sulfur colloid. Both of the radiopharmaceuticals can be prepared under aseptic conditions using an autoclav for heating without loss of activity. In vitro stability studies using various challenge solutions (water, normal saline, diluted synovial fluid) showed that 188Re labeled hydroxyapatite particles lost about 80% of their activity within 5 d in synovial fluid. Rhenium sulfur colloid on the other hand proved to be very stable with a remaining activity of more than 93% after 5 d in diluted synovial fluid. Conclusion: These in vitro results suggest that 188Re labeled rhenium sulfur colloid expects to be more suitable for therapeutic use in radiation synovectomy than the labeled hydroxyapatite particles.

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Utilizing ICG Spectroscopical Properties for Real-Time Nanoparticle Release Quantification In vitro and In vivo in Imaging Setups

Current Pharmaceutical Design ◽

10.2174/1381612826666200318170849 ◽

2020 ◽

Vol 26 (31) ◽

pp. 3828-3833 ◽

Cited By ~ 2

Author(s):

Tuula Peñate-Medina ◽

Eike Kraas ◽

Kunliang Luo ◽

Jana Humbert ◽

Hanwen Zhu ◽

...

Keyword(s):

Release Kinetics ◽

Pure Water ◽

Squamous Carcinoma ◽

Peak Shift ◽

Intensity Increase ◽

Nude Mouse Model ◽

Absorption And Emission ◽

Squamous Carcinoma Cells

Background: Nanoparticle imaging and tracking the release of the loaded material from the nanoparticle system have attracted significant attention in recent years. If the release of the loaded molecules could be monitored reliably in vivo, it would speed up the development of drug delivery systems remarkably. Methods: Here, we test a system that uses indocyanine green (ICG) as a fluorescent agent for studying release kinetics in vitro and in vivo from the lipid iron nanoparticle delivery system. The ICG spectral properties like its concentration dependence, sensitivity and the fluctuation of the absorption and emission wavelengths can be utilized for gathering information about the change of the ICG surrounding. Results: We have found that the absorption, fluorescence, and photoacoustic spectra of ICG in lipid iron nanoparticles differ from the spectra of ICG in pure water and plasma. We followed the ICG containing liposomal nanoparticle uptake into squamous carcinoma cells (SCC) by fluorescence microscopy and the in vivo uptake into SCC tumors in an orthotopic xenograft nude mouse model under a surgical microscope. Conclusion: Absorption and emission properties of ICG in the different solvent environment, like in plasma and human serum albumin, differ from those in aqueous solution. Photoacoustic spectral imaging confirmed a peak shift towards longer wavelengths and an intensity increase of ICG when bound to the lipids. The SCC cells showed that the ICG containing liposomes bind to the cell surface but are not internalized in the SCC-9 cells after 60 minutes of incubation. We also showed here that ICG containing liposomal nanoparticles can be traced under a surgical camera in vivo in orthotopic SCC xenografts in mice.

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In vitro Lipolysis as a Tool for the Establishment of IVIVC for Lipid-Based Drug Delivery Systems

Current Drug Delivery ◽

10.2174/1567201816666190620115716 ◽

2019 ◽

Vol 16 (8) ◽

pp. 688-697

Author(s):

Ravinder Verma ◽

Deepak Kaushik

Keyword(s):

Drug Delivery ◽

Ph Value ◽

Electron Paramagnetic Resonance Spectroscopy ◽

Rapid Screening ◽

Resonance Spectroscopy ◽

Fed State ◽

In Vitro Lipolysis ◽

Ph Stat

: In vitro lipolysis has emerged as a powerful tool in the development of in vitro in vivo correlation for Lipid-based Drug Delivery System (LbDDS). In vitro lipolysis possesses the ability to mimic the assimilation of LbDDS in the human biological system. The digestion medium for in vitro lipolysis commonly contains an aqueous buffer media, bile salts, phospholipids and sodium chloride. The concentrations of these compounds are defined by the physiological conditions prevailing in the fasted or fed state. The pH of the medium is monitored by a pH-sensitive electrode connected to a computercontrolled pH-stat device capable of maintaining a predefined pH value via titration with sodium hydroxide. Copenhagen, Monash and Jerusalem are used as different models for in vitro lipolysis studies. The most common approach used in evaluating the kinetics of lipolysis of emulsion-based encapsulation systems is the pH-stat titration technique. This is widely used in both the nutritional and the pharmacological research fields as a rapid screening tool. Analytical tools for the assessment of in vitro lipolysis include HPLC, GC, HPTLC, SEM, Cryo TEM, Electron paramagnetic resonance spectroscopy, Raman spectroscopy and Nanoparticle Tracking Analysis (NTA) for the characterization of the lipids and colloidal phases after digestion of lipids. Various researches have been carried out for the establishment of IVIVC by using in vitro lipolysis models. The current publication also presents an updated review of various researches in the field of in vitro lipolysis.

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Improving Topical Skin Delivery of Monocrotaline Via Liposome Gel-based Nanosystems

Current Drug Delivery ◽

10.2174/1567201816666191029125300 ◽

2019 ◽

Vol 16 (10) ◽

pp. 940-950 ◽

Cited By ~ 1

Author(s):

Jiandong Yu ◽

Zhi Chen ◽

Yan-zhi Yin ◽

Chaoyuan Tang ◽

Enying Hu ◽

...

Keyword(s):

Gradient Method ◽

Encapsulation Efficiency ◽

Ph Value ◽

Topical Administration ◽

Ph Gradient ◽

Stability Factor ◽

Buffer Solution ◽

Skin Delivery ◽

Skin Retention

Background: In this study, a liposomal gel based on a pH-gradient method was used to increase the skin-layer retention of monocrotaline (MCT) for topical administration. Methods: Using the Box-Behnken design, different formulations were designed to form liposome suspensions with optimal encapsulation efficiency (EE%) and stability factor (KE). In order to keep MCT in liposomes and accumulate in skin slowly and selectively, MCT liposome suspensions were engineered into gels. Results: A pH-gradient method was used to prepare liposome suspensions. The optimal formulation of liposome suspensions (encapsulation efficiency: 83.10 ± 0.21%) was as follows: MCT 12 mg, soybean phosphatidyl choline (sbPC) 200 mg, cholesterol (CH) 41 mg, vitamin E (VE) 5 mg, and citric acid buffer solution (CBS) 4.0 10 mL (pH 7.0). The final formulation of liposomal gels consisted of 32 mL liposome suspensions, 4.76 mL deionized water, 0.40 g Carbopol-940, 1.6 g glycerol, 0.04 g methylparaben, and a suitable amount of triethanolamine for pH value adjustment. The results of in vitro drug release showed that MCT in liposomal gels could be released in 12 h constantly in physiological saline as a Ritger-Peppas model. Compared with plain MCT in gel form, liposomal MCT in gel had higher skin retention in vitro. Conclusion: In this study, liposomal gels were formed for greater skin retention of MCT. It is potentially beneficial for reducing toxicities of MCT by topical administration with liposomal gel.

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