scholarly journals P137 DEGRADATION RESISTANCE OF PVDF MESH IN VIVO IN COMPARISON TO PP MESH

2021 ◽  
Vol 108 (Supplement_8) ◽  
Author(s):  
Hongshi Wang ◽  
Bernd Klosterhalfen ◽  
Andreas Müllen ◽  
Stephan Jockenhövel ◽  
Axel Dievernich ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Animal Experiment ◽  
Surface Condition ◽  
Ftir Spectra ◽  
Chemical Condition ◽  
Implantation Time ◽  
X Ray ◽  
Surface Cracking ◽  
Successful Removal

Abstract Aim To researched the degradation resistance of PVDF mesh by comparing its morphological and chemical condition with PP mesh. Material and Methods PVDF and PP meshes analysed in this study were received from a previous animal experiment. To expose the surface of explanted meshes, a tissue removing method with protease was used and the result of this cleaning process was tested by X-ray Photoelectron Spectroscopy (XPS). The morphological condition of the mesh surface was compared using Scanning Electron Microscopy (SEM) and the chemical condition concerning degradation was analysed through Fourier Transform Infrared Spectroscopy (FTIR). The surface condition of PVDF mesh after 3-, 6-, 12- and 24-month implantation was illustrated and compared with two types of PP meshes. Results XPS revealed an absence of nitrogen, confirming the successful removal of tissue residues using protease. SEM results presented no notable morphological surface change of the PVDF mesh and progressive surface cracking processes over time of both types of PP meshes. FTIR spectra of the implanted PVDF meshes had no considerable difference from the spectrum of the pristine mesh, while FTIR spectra of both types of PP meshes had extra chemical functional groups increasing with implantation time, indicating progressive degradation. Conclusions PVDF mesh does not show signs of degradation up to 24 months after implantation while PP meshes progressively degrade with increasing time under the same conditions, which appears as worsening Environmental Stress Cracks. This study highlights the morphological and chemical stability of the PVDF mesh and demonstrates that the PVDF mesh is more resistant to degradation in comparison to the PP meshes.

scholarly journals PROBLEMS OF DEVELOPMENT OF THE METHOD OF X-RAY PHOTOELECTRON SPECTROSCOPY IN UKRAINE

2021 ◽  
Vol 87 (1) ◽  
pp. 41-50
Author(s):  
Oleksandr Korduban ◽  
Volodymyr Ogenko ◽  
Taras Kryshchuk
Keyword(s):  
Photoelectron Spectroscopy ◽  
Materials Science ◽  
Surface Condition ◽  
Organometallic Compounds ◽  
Modern Method ◽  
High Tech ◽  
National Academy Of Sciences ◽  
Technical Problems ◽  
X Ray ◽  
Academy Of Sciences

The article is devoted to the development problems of the X-ray Photoelectron Spectroscopy (XPS) method in Ukraine. XPS is a modern method for studying the electronic structure of atoms. The XPS method is used at all stages of the synthesis and study of materials, the functional properties of which are determined by the state of the surface or interphase boundaries, charge states of atoms and the type of functional groups, and material degradation processes. The objects of study are catalysts, coatings, chemical sensors, sorbents, coordination and organometallic compounds (chemistry, materials science, phar­maceuticals), surface condition and composition (microelectronics), thin films (optics), alloys (aviation and space industry), nanopowders, nanofilms (nanotechnology). The method is relevant for the implementation of targeted synthesis of materials. In the world, the XPS method is widespread and integrated into innovative branches of science and technology, and XPS - instrumentation - is a high-tech business. In Ukraine, the method is practically not presented, there is no competition in this field of instrumentation. The article proposes the creation on the basis of the National Academy of Sciences of Ukraine a park of unitary, high-quality and affordable domestic XPS-spectrometers and the opening of a service center. The XPS method is necessary for most of the institutes of the National Academy of Sciences of Ukraine from the departments of chemistry, physics and astronomy, physical and technical problems of materials science, earth sciences and all specialized faculties of state universities. In general, for Ukraine, this is at least 50 spectrometers. The mechanism for the implementation of the project can be the formation of a state order for the development and manufacture of a batch of XPS spectrometers on the basis of imported and domestic components (50:50) and attracting business to the project. Creation of a network of Domestic XPS-spectrometers allows to obtain a sharp increase in the efficiency of scientific research in chemistry, physics, materials science and is one of the conditions for Ukraine’s transition to an innovative economy.

scholarly journals Surface-Modified Poly(l-lactide-co-glycolide) Scaffolds for the Treatment of Osteochondral Critical Size Defects—In Vivo Studies on Rabbits

2020 ◽  
Vol 21 (20) ◽  
pp. 7541
Author(s):  
Małgorzata Krok-Borkowicz ◽  
Katarzyna Reczyńska ◽  
Łucja Rumian ◽  
Elżbieta Menaszek ◽  
Maciej Orzelski ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Tissue Regeneration ◽  
Photoelectron Spectroscopy ◽  
Sessile Drop ◽  
Bone Tissue Regeneration ◽  
In Vivo Studies ◽  
In Vivo Model ◽  
Type I ◽  
X Ray

Poly(l-lactide-co-glycolide) (PLGA) porous scaffolds were modified with collagen type I (PLGA/coll) or hydroxyapatite (PLGA/HAp) and implanted in rabbits osteochondral defects to check their biocompatibility and bone tissue regeneration potential. The scaffolds were fabricated using solvent casting/particulate leaching method. Their total porosity was 85% and the pore size was in the range of 250–320 µm. The physico-chemical properties of the scaffolds were evaluated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), sessile drop, and compression tests. Three types of the scaffolds (unmodified PLGA, PLGA/coll, and PLGA/HAp) were implanted into the defects created in New Zealand rabbit femoral trochlears; empty defect acted as control. Samples were extracted after 1, 4, 12, and 26 weeks from the implantation, evaluated using micro-computed tomography (µCT), and stained by Masson–Goldner and hematoxylin-eosin. The results showed that the proposed method is suitable for fabrication of highly porous PLGA scaffolds. Effective deposition of both coll and HAp was confirmed on all surfaces of the pores through the entire scaffold volume. In the in vivo model, PLGA and PLGA/HAp scaffolds enhanced tissue ingrowth as shown by histological and morphometric analyses. Bone formation was the highest for PLGA/HAp scaffolds as evidenced by µCT. Neo-tissue formation in the defect site was well correlated with degradation kinetics of the scaffold material. Interestingly, around PLGA/coll extensive inflammation and inhibited tissue healing were detected, presumably due to immunological response of the host towards collagen of bovine origin. To summarize, PLGA scaffolds modified with HAp are the most promising materials for bone tissue regeneration.

scholarly journals Highly Efficient and Stable Removal of Arsenic by Live Cell Fabricated Magnetic Nanoparticles

2019 ◽  
Vol 20 (14) ◽  
pp. 3566
Author(s):  
Hyo Kyeong Kim ◽  
Sun-Wook Jeong ◽  
Jung Eun Yang ◽  
Yong Jun Choi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Iron Nanoparticles ◽  
Deinococcus Radiodurans ◽  
Specific Treatment ◽  
Arsenic Species ◽  
Live Cell ◽  
Toxic Substances ◽  
X Ray ◽  
Removal Capacity

As concerns about public health and environmental problems regarding contamination by toxic substances increase worldwide, the development of a highly effective and specific treatment method is imperative. Although physicochemical arsenic treatment methods have been developed, microbial in vivo remediation processes using live cell fabricated nanoparticles have not yet been reported. Herein, we report the development of magnetic iron nanoparticles immobilized an extremophilic microorganism, Deinococcus radiodurans R1, capable of removing toxic arsenic species. First, in vivo synthesis of magnetic iron nanoparticles was successfully achieved with the D. radiodurans R1 strain and characterized by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), dynamic light scattering (DLS), zeta-potential, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analysis. Second, the maximum removal capacity of the magnetic iron nanoparticle-immobilized D. radiodurans R1 strain (DR-FeNPs) for arsenic [As(V)] was evaluated under the optimized conditions. Finally, the removal capacity of DR-FeNPs in the presence of various competitive anions was also investigated to simulate the practical application. More than 98% of As(V) was efficiently removed by DR-FeNPs within 1 h, and the removal efficiency was stably maintained for up to 32 h (98.97%). Furthermore, the possibility of recovery of DR-FeNPs after use was also suggested using magnets as a proof-of-concept.

scholarly journals The Surface Characterisation of Fused Filament Fabricated (FFF) 3D Printed PEEK/Hydroxyapatite Composites

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3117
Author(s):  
Krzysztof Rodzeń ◽  
Mary Josephine McIvor ◽  
Preetam K. Sharma ◽  
Jonathan G. Acheson ◽  
Alistair McIlhagger ◽  
...  
Keyword(s):  
3D Printing ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Fused Filament Fabrication ◽  
Surface Characterisation ◽  
X Ray ◽  
3D Printed

Polyetheretherketone (PEEK) is a high-performance thermoplastic polymer which has found increasing application in orthopaedics and has shown a lot of promise for ‘made-to-measure’ implants via additive manufacturing approaches. However, PEEK is bioinert and needs to undergo surface modification to make it at least osteoconductive to ensure a more rapid, improved, and stable fixation that will last longer in vivo. One approach to solving this issue is to modify PEEK with bioactive agents such as hydroxyapatite (HA). The work reported in this study demonstrates the direct 3D printing of PEEK/HA composites of up to 30 weight percent (wt%) HA using a Fused Filament Fabrication (FFF) approach. The surface characteristics and in vitro properties of the composite materials were investigated. X-ray diffraction revealed the samples to be semi-crystalline in nature, with X-ray Photoelectron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry revealing HA materials were available in the uppermost surface of all the 3D printed samples. In vitro testing of the samples at 7 days demonstrated that the PEEK/HA composite surfaces supported the adherence and growth of viable U-2 OS osteoblast like cells. These results demonstrate that FFF can deliver bioactive HA on the surface of PEEK bio-composites in a one-step 3D printing process.

scholarly journals Surface Modified β-Tricalcium phosphate enhanced stem cell osteogenic differentiation in vitro and bone regeneration in vivo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheuk Sing Choy ◽  
Wei Fang Lee ◽  
Pei Ying Lin ◽  
Yi-Fan Wu ◽  
Haw-Ming Huang ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Tricalcium Phosphate ◽  
Photoelectron Spectroscopy ◽  
Osteoblastic Differentiation ◽  
Water Soluble ◽  
Glow Discharge Plasma ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Micro Particles

AbstractA major number of studies have demonstrated Beta-tricalcium phosphate (β-TCP) biocompatibility, bioactivity, and osteoconductivity characteristics in bone regeneration. The aim of this research was to enhance β-TCP's biocompatibility, and evaluate its physicochemical properties by argon glow discharge plasma (GDP) plasma surface treatment without modifying its surface. Treated β-TCP was analyzed by scanning electron microscopy (SEM), energy-dispersive spectrometry, X-ray photoelectron spectroscopy (XPS), X-ray diffraction analysis, and Fourier transform infrared spectroscopy characterization. To evaluate treated β-TCP biocompatibility and osteoblastic differentiation, water-soluble tetrazolium salts-1 (WST-1), immunofluorescence, alkaline phosphatase (ALP) assay, and quantitative real-time polymerase chain reaction (QPCR) were done using human mesenchymal stem cells (hMSCs). The results indicated a slight enhancement of the β-TCP by GDP sputtering, which resulted in a higher Ca/P ratio (2.05) than the control. Furthermore, when compared with control β-TCP, we observed an improvement of WST-1 on all days (p < 0.05) as well as of ALP activity (day 7, p < 0.05), with up-regulation of ALP, osteocalcin, and Osteoprotegerin osteogenic genes in cells cultured with the treated β-TCP. XPS and SEM results indicated that treated β-TCP’s surface was not modified. In vivo, micro-computed tomography and histomorphometric analysis indicated that the β-TCP test managed to regenerate more new bone than the untreated β-TCP and control defects at 8 weeks (p < 0.05). Argon GDP treatment is a viable method for removing macro and micro particles of < 7 μm in size from β-TCP bigger particles surfaces and therefore improving its biocompatibility with slight surface roughness modification, enhancing hMSCs proliferation, osteoblastic differentiation, and stimulating more new bone formation.

scholarly journals Impact of Crystal Habit on the Dissolution Rate and In Vivo Pharmacokinetics of Sorafenib Tosylate

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3469
Author(s):  
Chi Uyen Phan ◽  
Jie Shen ◽  
Kaxi Yu ◽  
Jianming Mao ◽  
Guping Tang
Keyword(s):  
Dissolution Rate ◽  
Photoelectron Spectroscopy ◽  
Class Ii ◽  
Crystal Habit ◽  
Factors Affecting ◽  
X Ray ◽  
Bcs Class Ii ◽  
Rate Limiting Step ◽  
In Vivo Pharmacokinetics

The dissolution rate is the rate-limiting step for Biopharmaceutics Classification System (BCS) class II drugs to enhance their in vivo pharmacokinetic behaviors. There are some factors affecting the dissolution rate, such as polymorphism, particle size, and crystal habit. In this study, to improve the dissolution rate and enhance the in vivo pharmacokinetics of sorafenib tosylate (Sor-Tos), a BCS class II drug, two crystal habits of Sor-Tos were prepared. A plate-shaped crystal habit (ST-A) and a needle-shaped crystal habit (ST-B) were harvested by recrystallization from acetone (ACN) and n-butanol (BuOH), respectively. The surface chemistry of the two crystal habits was determined by powder X-ray diffraction (PXRD) data, molecular modeling, and face indexation analysis, and confirmed by X-ray photoelectron spectroscopy (XPS) data. The results showed that ST-B had a larger hydrophilic surface than ST-A, and subsequently a higher dissolution rate and a substantial enhancement of the in vivo pharmacokinetic performance of ST-B.

scholarly journals Bimodal Ultrasound and X-Ray Bioimaging Properties of Particulate Calcium Fluoride Biomaterial

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5447
Author(s):  
Cristhian Marcelo Chingo Aimacaña ◽  
Kevin O. Pila ◽  
Dilan A. Quinchiguango Perez ◽  
Alexis Debut ◽  
Mohamed F. Attia ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Calcium Fluoride ◽  
In Vitro Cytotoxicity ◽  
Diagnostic Methods ◽  
Face Centered Cubic ◽  
X Ray ◽  
Peak Broadening ◽  
X Ray Imaging

Ultrasound (US) and X-ray imaging are diagnostic methods that are commonly used to image internal body structures. Several organic and inorganic imaging contrast agents are commercially available. However, their synthesis and purification remain challenging, in addition to posing safety issues. Here, we report on the promise of widespread, safe, and easy-to-produce particulate calcium fluoride (part-CaF2) as a bimodal US and X-ray contrast agent. Pure and highly crystalline part-CaF2 is obtained using a cheap commercial product. Scanning electron microscopy (SEM) depicts the morphology of these particles, while energy-dispersive X-ray spectroscopy (EDS) confirms their chemical composition. Diffuse reflectance ultraviolet-visible spectroscopy highlights their insulating behavior. The X-ray diffraction (XRD) pattern reveals that part-CaF2 crystallizes in the face-centered cubic cell lattice. Further analyses regarding peak broadening are performed using the Scherrer and Williamson–Hall (W-H) methods, which pinpoint the small crystallite size and the presence of lattice strain. X-ray photoelectron spectroscopy (XPS) solely exhibits specific peaks related to CaF2, confirming the absence of any contamination. Additionally, in vitro cytotoxicity and in vivo maximum tolerated dose (MTD) tests prove the biocompatibility of part-CaF2. Finally, the results of the US and X-ray imaging tests strongly signal that part-CaF2 could be exploited in bimodal bioimaging applications. These findings may shed a new light on calcium fluoride and the opportunities it offers in biomedical engineering.

scholarly journals Surface and Bulk Modifications of Fibrous Erionite in Mimicked Gamble’s Solution at Acidic pH

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 914
Author(s):  
Alessandro Pacella ◽  
Paolo Ballirano ◽  
Marzia Fantauzzi ◽  
Antonella Rossi ◽  
Cecilia Viti ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Morphological Changes ◽  
Biological Effects ◽  
Emission Spectrometry ◽  
Primary Role ◽  
Acidic Ph ◽  
X Ray

This study aimed at investigating both the surface and bulk modifications occurring on fibrous erionite during leaching in a mimicked Gamble’s solution (MGS) at pH of 4.5 and T = 37 °C, up to one month of incubation. Samples were characterized by a multi-analytical approach: field-emission scanning electron microscopy (FE-SEM) was employed to investigate the morphological changes of both pristine and reacted fibres, inductively coupled plasma optical emission spectrometry (ICP-OES) was used to measure the concentration of the released cations; X-ray photoelectron spectroscopy (XPS) was exploited for highlighting possible modifications of surface chemistry; X-ray powder diffraction (XRPD) and high-resolution transmission electron microscopy (HR-TEM) were applied aiming to get information on the structural state of the fibres following the incubation. ICP results integrated with those obtained by both bulk- and surface-chemical characterization highlighted that erionite binds Na especially in the first 24 h of sample incubation in the MGS, following ion exchange with the extra framework cations, in particular Ca. Moreover, our new results show that the Na binding process caused structural modifications with the migration of Na toward the Ca2 site and redistribution of the cations within the erionite cage. TEM investigation pointed out that the interaction between erionite and MGS results in the formation of a new surface amorphous layer with an irregular lobate pattern on an earlier surface weathered layer. However, the silicate framework is not weakened by incubation in the MGS at acidic pH. In addition, on the basis of the Si release normalized to the mineral surface area, fibrous erionite resulted significantly more biodurable than amphibole asbestos. Notably, considering the primary role played by biodurability in inducing pathogenicity, this result certainly supports in vivo observations showing that erionite is much more tumorigenic than asbestos. Moreover, the ions released by erionite when immersed in MGS may trigger biological effects, such as those on lipid packing and membrane permeability. On this basis, we expect a regulatory definition that would provide protection from this carcinogenic fibre.

scholarly journals Graphene Reinforced Polyether Ether Ketone Nanocomposites for Bone Repair Applications

2020 ◽  
Author(s):  
Nan Jiang ◽  
Peijie Tan ◽  
Miaomiao He ◽  
dan Sun ◽  
Li Zhang ◽  
...  
Keyword(s):  
Mechanical Testing ◽  
Photoelectron Spectroscopy ◽  
Bone Repair ◽  
Early Stage ◽  
Angle Measurement ◽  
X Ray ◽  
Polyether Ether Ketone ◽  
Ether Ketone

To improve the performance of polyether ether ketone matrix (PEEK) in hard tissue repair and replacement applications, we fabricated graphene (G) reinforced PEEK with graded G concentrations (0.1%-5%) through injection molding. The mechanical properties, surface morphology, chemical composition and thermal stability of the composites have been characterized through universal mechanical testing, scanning electron microscopy, contact-angle measurement, transmission electron microscope, X-ray photoelectron spectroscopy, X-ray diffraction and thermal analysis system. The biocompatibility has been assessed in vitro and the bone repair function of the composite implant have been assessed in vivo using a rabbit mandibular bone defect model. Mechanical testing results suggest that the composite samples have compressive moduli similar to that of the natural bone. Although addition of G into PEEK does not significantly influence the composite tensile, flexural or compressive moduli, it can significantly enhance the ductility and toughness of the material. On the other hand, all G-reinforced PEEK implants demonstrated enhanced adhesion and differentiation of rat bone marrow stromal cells (BMSCs), with 5% G-PEEK showing the highest bioactivity among all samples. The in vivo osseointegration data further revealed that 5% G-PEEK has the best effect in promoting osseointegration and bone regeneration, in both early stage and late stage bone re-growth. Study shows that our G-reinforced PEEK-based implants provides a promising strategy for enhancing the performance of future regenerative bone implants.<br>

Surface Modified β-Tricalcium Phosphate Enhanced Stem Cell Osteogenic Differentiation in Vitro and Bone Regeneration in Vivo

2020 ◽  
Author(s):  
Cheuk Sing Choy ◽  
Wei Fang Lee ◽  
Pei Ying Lin ◽  
Yi-Fan Wu ◽  
Haw-Ming Huang ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Tricalcium Phosphate ◽  
Photoelectron Spectroscopy ◽  
Osteoblastic Differentiation ◽  
Water Soluble ◽  
Glow Discharge Plasma ◽  
X Ray ◽  
Micro Particles

Abstract In vitro, in vivo, and clinical studies had demonstrated Beta-tricalcium phosphate (β-TCP) biocompatibility, bioactivity, and osteoconductivity in bone regeneration. The present research aimed to enhance β-TCP's biocompatibility and physical and chemical properties by argon plasma surface treatment without surface modification. Treated β-TCP characterization was done by scanning electron microscopy (SEM), energy-dispersive spectrometry, X-ray photoelectron spectroscopy (XPS), X-ray diffraction analysis, and Fourier transform infrared spectroscopy characterization. The viability of human mesenchymal stem cells (hMSCs) and osteoblastic differentiation were determined by water-soluble tetrazolium salts-1 (WST-1), immunofluorescence, alkaline phosphatase (ALP) assay, and quantitative real-time polymerase chain reaction. The results indicated a slight enhancement of the β-TCP by argon glow discharge plasma (GDP) sputtering, which resulted in a higher Ca/P ratio (2.05) than the control. Furthermore, when compared withcontrol β-TCP, we observed an improvement of WST-1 on all days (p < 0.05) as well as of ALP activity (day 7, p < 0.05), with up-regulation of ALP, osteocalcin, and Osteoprotegerin osteogenic genes in cells cultured with the β-TCP test. XPS and SEM analyses indicated treated β-TCP’s surface was not modified when impurities were removed. In vivo, micro-computed tomography and histomorphometric analysis indicated that the β-TCP test managed to regenerate more new bone than the β-TCP control and was able to control defects at 8 weeks (p < 0.05). Argon GDP treatment is a viable method for removing macro and micro particles of <7 μm in size from β-TCP bigger particles surfaces while improving its biocompatibility with slight surface roughness modification, enhancing hMSCs proliferation, osteoblastic differentiation, and stimulating more new bone formation.

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