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 ◽  
...  

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.

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Alexandre Pancotti ◽  
Dener Pereira Santos ◽  
Dielly Oliveira Morais ◽  
Mauro Vinícius de Barros Souza ◽  
Débora R. Lima ◽  
...  

AbstractIn this study, we report the synthesis and characterization of NiFe2O4 and CoFe2O4 nanoparticles (NPs) which are widely used in the biomedical area. There is still limited knowledge how the properties of these materials are influenced by different chemical routes. In this work, we investigated the effect of heat treatment over cytotoxicity of cobalt and niquel ferrites NPs synthesized by sol-gel method. Then the samples were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), Fourier Transform Infrared Spectroscopy Analysis (FTIR), and X-ray fluorescence (XRF). The average crystallite sizes of the particles were found to be in the range of 20–35 nm. The hemocompatibility (erythrocytes and leukocytes) was checked. Cytotoxicity results were similar to those of the control test sample, therefore suggesting hemocompatibility of the tested materials.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 825
Author(s):  
Saman Sargazi ◽  
Mohammad Reza Hajinezhad ◽  
Abbas Rahdar ◽  
Muhammad Nadeem Zafar ◽  
Aneesa Awan ◽  
...  

In this research, tin ferrite (SnFe2O4) NPs were synthesized via hydrothermal route using ferric chloride and tin chloride as precursors and were then characterized in terms of morphology and structure using Fourier-transform infrared spectroscopy (FTIR), Ultraviolet–visible spectroscopy (UV-Vis), X-ray power diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and Brunauer–Emmett–Teller (BET) method. The obtained UV-Vis spectra was used to measure band gap energy of as-prepared SnFe2O4 NPs. XRD confirmed the spinel structure of NPs, while SEM and TEM analyses disclosed the size of NPs in the range of 15–50 nm and revealed the spherical shape of NPs. Moreover, energy dispersive X-ray spectroscopy (EDS) and BET analysis was carried out to estimate elemental composition and specific surface area, respectively. In vitro cytotoxicity of the synthesized NPs were studied on normal (HUVEC, HEK293) and cancerous (A549) human cell lines. HUVEC cells were resistant to SnFe2O4 NPs; while a significant decrease in the viability of HEK293 cells was observed when treated with higher concentrations of SnFe2O4 NPs. Furthermore, SnFe2O4 NPs induced dramatic cytotoxicity against A549 cells. For in vivo study, rats received SnFe2O4 NPs at dosages of 0, 0.1, 1, and 10 mg/kg. The 10 mg/kg dose increased serum blood urea nitrogen and creatinine compared to the controls (P < 0.05). The pathology showed necrosis in the liver, heart, and lungs, and the greatest damages were related to the kidneys. Overall, the in vivo and in vitro experiments showed that SnFe2O4 NPs at high doses had toxic effects on lung, liver and kidney cells without inducing toxicity to HUVECs. Further studies are warranted to fully elucidate the side effects of SnFe2O4 NPs for their application in theranostics.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3117
Author(s):  
Krzysztof Rodzeń ◽  
Mary Josephine McIvor ◽  
Preetam K. Sharma ◽  
Jonathan G. Acheson ◽  
Alistair McIlhagger ◽  
...  

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.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Dorota A Kedziorek ◽  
Piotr Walczak ◽  
Yingli Fu ◽  
Nicole Azene ◽  
Aravind Arepally ◽  
...  

Introduction: Therapeutic angiogenesis in Peripheral Arterial Disease (PAD) using stem cell therapy is potentially complicated by immunorejection. To overcome this problem, microen-capsulation using the alginate-poly-L-lysine (PLL)-alginate (APA) method was developed to provide a protective porous bubble to block antibodies but allow exchange of small molecules. Recently, we have developed a method to enable X-ray detection of these capsules. However, cell survival within the capsules could not be determined. Plus PLL can be mildly cytotoxic. In the present study, we combined reporter gene methods to verify cell survival with X-ray detection of the microcapsules in a rabbit PAD model and studied the PLL impact on cell viability. Methods: Rabbit mesenchymal stem cells (MSCs) were transfected with triple fusion (TF) reporter gene for bioluminescence (firefly luciferase), fluorescence (red fluorescent protein) and PET (truncated thymidine kinase). TF-MSCs were encapsulated in the perfluorooctyl bromide (PFOB) capsules to enable computed tomographic detection. Capsule crosslinking was performed with three PLL concentrations, i.e., 0.005%, 0.025% and 0.05%. Bioluminescent imaging (BLI) was used to monitor cells survival for one week in vitro and after intramuscular injection in vivo . Results: Serial in vitro BLI enabled the detection of viable encapsulated MSCs without detrimental signal degradation (~13% decrease of BLI signal intensity after PFOB encapsulation comparing to equal number of naked MSCs). PLL did not result in cell death; higher PLL concentrations were correlated with stronger BLI signal. BLI signal production was only slightly reduced by second layer of alginate (~80% for 0.05% PLL). In vivo BLI demonstrated the detection of naked, APA, and PFOB-encapsulated TF-MSCs. X-ray imaging enabled PFOB microcapsules detection relative to vasculature. Conclusion: BLI allows monitoring of encapsulated cells survival. PLL concentrations ≤ 0.05% appear safe for encapsulated cells with higher concentration being associated with enhanced crosslinking and capsule stability. MSCs expressing TF reporter in PFOB microcapsules enables dual monitoring of cell delivery/capsule tracking by X-ray imaging and cell viability with BLI.


Author(s):  
Nishad Km ◽  
Arul B ◽  
Rajasekaran S

 Objective: The present investigation was to formulate controlled release of mucoadhesive clarithromycin tablets using natural polymers.Methods: Tamarind seed polysaccharide obtained from Tamarindus indica and chitosan act as natural polymers. The formulated tablets of the combined form of thrombospondin (TSP) and chitosan were analyzed by in vitro dissolution method. The optimized formulations were selected for ex vivo and in vivo studies and compared with hydroxypropyl methylcellulose K100 polymer by evaluating gastric retention period by X-ray imaging technique, and drug bioavailability by a pharmacokinetic method from blood samples was determined by high-performance liquid chromatography-mass spectrometry method.Results: The gastric mucoadhesive tablets were prepared using chito-TSP polymers. The in vitro drug release showed good release character for 24 h. The ex vivo studies of tablets showed good adhesive property for a long time. The X-ray imaging technique also proved the adhesive character of tablets. From blood serum sample of rabbits, bioavailability of the drug is in according to the controlled release mechanism.Conclusion: The selected formulations were subjected to stability studies. The study concluded that combination of chitosan and TSP is best natural polymer for mucoadhesion by the advantages of controlled release and biodegradation.


Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3476
Author(s):  
Mohamed Rahamathulla ◽  
Srinivasan Saisivam ◽  
Abdullah Alshetaili ◽  
Umme Hani ◽  
Hosahalli Veerabhadrappa Gangadharappa ◽  
...  

Losartan potassium (LP) is an angiotensin receptor blocker used to treat hypertension. At higher pH, it shows poor aqueous solubility, which leads to poor bioavailability and lowers its therapeutic effectiveness. The main aim of this research was to develop a direct compressed effervescent floating matrix tablet (EFMT) of LP using hydroxyl propyl methylcellulose 90SH 15,000 (HPMC-90SH 15,000), karaya gum (KG), and an effervescent agent, such as sodium bicarbonate (SB). Therefore, an EFMT has been developed to prolong the stomach residence time (GRT) of a drug to several hours and improve its bioavailability in the stomach region. The blended powder was evaluated for pre-compression characteristics, followed by post-compression characteristics, in vitro floating, water uptake studies, and in vitro studies. The optimized formulation of EFMT was investigated for in vivo buoyancy by X-ray imaging and pharmacokinetic studies in Albino rabbits. The results revealed that the parameters of pre- and post-compression were within the USP limits. All tablets showed good floating capabilities (short floating lag time <1 min and floated for >24 h), good swelling characteristics, and controlled release for over 24 h. The Fourier-transform infrared (FTIR) and differential scanning calorimetry (DSC) spectra showed drug–polymer compatibility. The optimized formulation F3 (HPMC-90SH 15,000-KG) exhibited non-Fickian diffusion and showed 100% drug release at the end of 24 h. In addition, with the optimized formulation F3, we observed that the EFMT floated continuously in the rabbit’s stomach area; thus, the GRT could be extended to more than 12 h. The pharmacokinetic profiling in Albino rabbits revealed that the relative bioavailability of the optimized LP-EFMT was enhanced compared to an oral solution of LP. We conclude that this a potential method for improving the oral bioavailability of LP to treat hypertension effectively.


2020 ◽  
Author(s):  
Nan Jiang ◽  
Peijie Tan ◽  
Miaomiao He ◽  
dan Sun ◽  
Li Zhang ◽  
...  

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>


2020 ◽  
Author(s):  
Cheuk Sing Choy ◽  
Wei Fang Lee ◽  
Pei Ying Lin ◽  
Yi-Fan Wu ◽  
Haw-Ming Huang ◽  
...  

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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