scholarly journals Biological Characterization of Polymeric Matrix and Graphene Oxide Biocomposites Filaments for Biomedical Implant Applications: A Preliminary Report

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3382
Author(s):  
Thamires Santos Silva ◽  
Marcelo Melo Soares ◽  
Ana Claudia Oliveira Carreira ◽  
Gustavo de Sá Schiavo Matias ◽  
Carolina Coming Tegon ◽  
...  

Carbon nanostructures application, such as graphene (Gr) and graphene oxide (GO), provides suitable efforts for new material acquirement in biomedical areas. By aiming to combine the unique physicochemical properties of GO to Poly L-lactic acid (PLLA), PLLA-GO filaments were produced and characterized by X-ray diffraction (XRD). The in vivo biocompatibility of these nanocomposites was performed by subcutaneous and intramuscular implantation in adult Wistar rats. Evaluation of the implantation inflammatory response (21 days) and mesenchymal stem cells (MSCs) with PLLA-GO took place in culture for 7 days. Through XRD, new crystallographic planes were formed by mixing GO with PLLA (PLLA-GO). Using macroscopic analysis, GO implanted in the subcutaneous region showed particles’ organization, forming a structure similar to a ribbon, without tissue invasion. Histologically, no tissue architecture changes were observed, and PLLA-GO cell adhesion was demonstrated by scanning electron microscopy (SEM). Finally, PLLA-GO nanocomposites showed promising results due to the in vivo biocompatibility test, which demonstrated effective integration and absence of inflammation after 21 days of implantation. These results indicate the future use of PLLA-GO nanocomposites as a new effort for tissue engineering (TE) application, although further analysis is required to evaluate their proliferative capacity and viability.

Author(s):  
K A Hing ◽  
S M Best ◽  
K E Tanner ◽  
P A Revell ◽  
W Bonfield

The standardization of characterization techniques is becoming increasingly important for bone replacement materials as it becomes apparent that, for the field to advance, testing must be developed to allow the biocompatibility or bioactivity of a new material to be assessed and directly compared with existing materials. Currently there are many forms of biocompatibility test for materials destined for the osseous environment, ranging from immersion in simulated body fluid to implantation into living bone. However, the variety of ways in which the data from these tests may be acquired and interpreted, as a result of changes in parameters such as surgical technique and mechanical test conditions, means that much of the published data within the field is not comparable. This paper will introduce the concept of biocompatibility by considering calcium phosphate bioceramics, and discusses some aspects of in vivo experimental design, including simple histomorphometry techniques, in addition to considering practical methods for the assessment of the biomechanical characteristics of an osseointegrated implant.


Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 189 ◽  
Author(s):  
George Mihail Vlasceanu ◽  
Livia Elena Crica ◽  
Andreea Madalina Pandele ◽  
Mariana Ionita

This study was targeted towards the synthesis and characterization of new chitosan–gelatin biocomposite films reinforced with graphene oxide and crosslinked with genipin. The composites’ mode of structuration was characterized by Fourier Transform Infrared spectroscopy and X-ray diffraction, while morphology and topography were investigated by scanning electron microscopy, nano-computer tomography and profilometry. Eventually, thermal stability was evaluated through thermogravimetrical analysis, mechanical properties assessment was carried out to detect potential improvements as a result of graphene oxide (GO) addition and in vitro enzyme degradation was performed to discern the most promising formulations for the maturation of the study towards in vivo assays. In accordance with similar works, results indicated the possibility of using GO as an agent for adjusting films’ roughness, chemical stability and polymer structuration. The enzymatic stability of chitosan–gelatin (CHT-GEL) films was also improved by genipin (GEN) crosslinking and GO supplementation, with the best results being obtained for CHT-GEL-GEN and CHT-GEL-GEN-GO3 (crosslinked formulation with 3 wt.% GO). Yet, contrary to previous reports, no great enhancement of CHT-GEN-GEL-GO thermal performances was obtained by the incorporation of GO.


Carbon ◽  
2016 ◽  
Vol 103 ◽  
pp. 291-298 ◽  
Author(s):  
Valeria Ettorre ◽  
Patrizia De Marco ◽  
Susi Zara ◽  
Vittoria Perrotti ◽  
Antonio Scarano ◽  
...  

2021 ◽  
Author(s):  
imane baba ◽  
Mounsif Ibnoussina ◽  
Omar Witam ◽  
Latifa Saadi

<p>Over the last few decades, the construction industry has become interested in materials that are durable, environmentally friendly and easily recyclable. This interest is due to the advantages these materials offer, among others local availability, low carbon footprint, energy efficiency and indoor comfort. The objective of this work is to study the properties of plasters prepared from a mixture of two types of gypsum. We were interested in the evolution of thermal conductivity, mechanical resistance and setting time as a function of the percentage of addition.</p><p>Two types of gypsum were studied, the first one belongs to the Safi basin and the second one comes from the High Atlas of Marrakech.</p><p>The characterization of the gypsums was necessary to determine its physical and geotechnical properties, its mineralogy, its thermal behavior and its microscopic structure. Several analyses were developed such as density measurement by pycnometer, X-ray diffraction, infrared spectroscopy and scanning electron microscopy.</p><p>We have made samples, of standardized dimensions, of mixtures based on both types of plaster. The water/gypsum mass ratio was set at 0.75.</p><p>The results revealed that the properties of gypsum as well as the percentage of addition affect the mechanical and thermal properties and the setting time of the composite material. The addition of the High Atlas gypsum of Marrakech allowed improving the material in terms of thermal insulation. The results of the other tests will be communicated later.</p>


2019 ◽  
pp. 089270571988909
Author(s):  
Sedigheh Khalili ◽  
Zahra Rafiee

The ternary superparamagnetic nanocomposites consisting of graphene oxide (GO), Fe3O4 nanoparticles, and optically active poly(amide-imide) (PAI) were fabricated in three steps consisting of a facile one-pot in situ growth of Fe3O4 on GO, resulted in the preparation of the magnetic Fe3O4@GO, modification of Fe3O4@GO by 3-aminopropyltriethoxy silane to introduce amino groups on its surface, and subsequently its compositing by various levels of 5, 10, and 15 wt% with chiral PAI derived from 3,5-diamino- N-(4-(di(1H-indol-3-yl)methyl)phenyl)benzamide and N, N′-(4,4′-carbonyldiphthaloyl)-bis-l-phenylalanine diacid through ultrasonic irradiation. Characterization of the resulting nanocomposites was performed by Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer, scanning electron microscope (SEM), and thermogravimetric analysis (TGA). The SEM analysis showed Fe3O4 nanoparticles with 30 nm size successfully decorated the GO nanosheets. The TGA analysis established the expected thermal stabilities for PAI/Fe3O4@GO nanocomposites. Furthermore, incorporation of Fe3O4@GO in polymer matrix improved the mechanical properties substantially. PAI/Fe3O4@GO 10 wt% was used to evaluate the sorption properties of Hg2+ at pH 7.


2016 ◽  
Vol 25 (6) ◽  
pp. 096369351602500 ◽  
Author(s):  
Ruimin Fu ◽  
Mingfu Zhu

Nowadays, the hummers method for preparation of graphene oxide (GO) was improved. The grapheme oxide @ Fe3O4 magnetic nanocomposites were synthesized by co-precipitation method. After analysing the morphology and structure of obtained nanocomposites by X-ray diffraction (XRD), transmission electron microscope (TEM) and Fourier transform infrared (FT-IR) spectroscopy, the result was shown as follows. The particle size of Fe3O4 in nanocomposites is 30 nm. Many functional groups are found in grapheme oxide, and such groups could be used to bind with the drug. In the test for magnetic properties, the nanocomposites gathered rapidly in the vicinity of the permanent magnet. The nanocomposites, with high superparamagnetism, can be used in the following applications: drug targeting transports, drug carrier, and diagnosis assistant system.


2009 ◽  
Vol 416 ◽  
pp. 416-420 ◽  
Author(s):  
Wei Li ◽  
Zhi Yang Song ◽  
Tian Ming Yu ◽  
Bao Gong Geng

A new BCB (Bamboo Charcoal Bonded) grinding wheel was developed by bamboo charcoal-phenolic resin composite under vacuum for ELID grinding technology. The pyrolysis behavior of the new bamboo charcoal-phenolic resin material was studied by thermo gravimetric analysis (TGA), and structural characterization of the new material was performed by scanning electron microscopy (SEM), X-ray diffraction (XRD), the friction characteristics was also investigated in this paper.


2018 ◽  
Vol 792 ◽  
pp. 89-97
Author(s):  
Xiao Feng Zhao ◽  
Zi Li Yu ◽  
Cong Li Fu ◽  
Xiu Li Wang

For many excellent graphene derivatives, tailoring the material properties is crucial to get a broader application. In the present work, a series of fluorinated graphene oxide (FGO) with various oxidation degree were synthesized using a modified Hummers method at different reaction temperatures. The structure and property of FGO were analyzed by X-ray diffraction (XRD), Fourier transform infra-red spectra (FT-IR), X-ray photoelectron spectra (XPS) and Zeta potential analysis. The results indicate that the oxygen contents range from 5.61 % to 21.96 % in FGO can be tuned by altering the reaction temperatures. The oxygen in FGO is presented mainly in the form of epoxide and carboxyl groups. With increasing reaction temperature from 50 °C to 90 °C, the oxygen content in FGO decreases and thicker multilayered FGO is formed with lower dispersibility.


2019 ◽  
Vol 4 (2) ◽  
pp. 130-137
Author(s):  
Satya Sankar Sahoo ◽  
Chandu Babu Rao

The objective of this study was to formulate and optimize a stable rilpivirine nanosuspension. In the present study, yttrium stabilized zirconium oxide beads being used as the milling media in nanomilling process. The lyophilized nanocrystals were being characterized by particle size distribution (PSD), polydispersity index (PDI), X-ray diffraction (XRD) and FTIR (Fourier transform infrared spectroscopy). Optimized nanosuspension has mean particle diameter of 266 nm, PDI of 0.158, zeta potential of 22.1 mV and spherical in shape with surface oriented stabilizer molecules. Flow properties like sedimentation volume, poura-bility with the F value of 0.94 and also the redispersability even after 4 weeks of storage was found to be satisfactory for the optimized nano-suspension. Many folds increase in solubility and rate of drug release observed, The lyophilized nanocrystals retains its crystallinity after nanomilling, stable chemically with high drug content, therefore, the developed nanosuspension would be an alternative better formulation than its conventional formulation to address its bioavailability issue. However, this should be further confirmed by appropriate techniques in vivo studies.


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