scholarly journals Nanocomposite Films of Chitosan-Grafted Carbon Nano-Onions for Biomedical Applications

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1203 ◽  
Author(s):  
Carlos David Grande Tovar ◽  
Jorge Iván Castro ◽  
Carlos Humberto Valencia ◽  
Diana Paola Navia Porras ◽  
José Herminsul Mina Hernandez ◽  
...  

The design of scaffolding from biocompatible and resistant materials such as carbon nanomaterials and biopolymers has become very important, given the high rate of injured patients. Graphene and carbon nanotubes, for example, have been used to improve the physical, mechanical, and biological properties of different materials and devices. In this work, we report the grafting of carbon nano-onions with chitosan (CS-g-CNO) through an amide-type bond. These compounds were blended with chitosan and polyvinyl alcohol composites to produce films for subdermal implantation in Wistar rats. Films with physical mixture between chitosan, polyvinyl alcohol, and carbon nano-onions were also prepared for comparison purposes. Film characterization was performed with Fourier Transformation Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Tensile strength, X-ray Diffraction Spectroscopy (XRD), and Scanning Electron Microscopy (SEM). The degradation of films into simulated body fluid (SBF) showed losses between 14% and 16% of the initial weight after 25 days of treatment. Still, a faster degradation (weight loss and pH changes) was obtained with composites of CS-g-CNO due to a higher SBF interaction by hydrogen bonding. On the other hand, in vivo evaluation of nanocomposites during 30 days in Wistar rats, subdermal tissue demonstrated normal resorption of the materials with lower inflammation processes as compared with the physical blends of ox-CNO formulations. SBF hydrolytic results agreed with the in vivo degradation for all samples, demonstrating that with a higher ox-CNO content increased the stability of the material and decreased its degradation capacity; however, we observed greater reabsorption with the formulations including CS-g-CNO. With this research, we demonstrated the future impact of CS/PVA/CS-g-CNO nanocomposite films for biomedical applications.

Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 684 ◽  
Author(s):  
Carlos Grande Tovar ◽  
Jorge Castro ◽  
Carlos Valencia ◽  
Diana Navia Porras ◽  
José Mina Hernandez ◽  
...  

Recently, tissue engineering became a very important medical alternative in patients who need to regenerate damaged or lost tissues through the use of scaffolds that support cell adhesion and proliferation. Carbon nanomaterials (carbon nanotubes, fullerenes, multi-wall fullerenes, and graphene) became a very important alternative to reinforce the mechanical, thermal, and antimicrobial properties of several biopolymers. In this work, five different formulations of chitosan/poly(vinyl alcohol)/oxidized carbon nano-onions (CS/PVA/ox-CNO) were used to prepare biodegradable scaffolds with potential biomedical applications. Film characterization consisted of Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tension strength, Young’s modulus, X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The degradation in a simulated body fluid (FBS) demonstrated that all the formulations lost between 75% and 80% of their weight after 15 days of treatment, but the degradation decreased with the ox-CNO content. In vivo tests after 90 days of subdermal implantation of the nanocomposite films in Wistar rats’ tissue demonstrated good biocompatibility without allergenic reactions or pus formation. There was a good correlation between FBS hydrolytic degradation and degradation in vivo for all the samples, since the ox-CNO content increased the stability of the material. All these results indicate the potential of the CS/PVA/ox-CNO nanocomposite films in tissue engineering, especially for long-term applications.


Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension.  From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Fausta Loffredo ◽  
Loredana Tammaro ◽  
Tiziana Di Luccio ◽  
Carmela Borriello ◽  
Fulvia Villani ◽  
...  

AbstractTungsten disulfide (WS2) nanotubes (NTs) are examined here as a filler for polylactide (PLA) for their ability to accelerate PLA crystallization and for their promising biocompatibility in relevant to biomedical applications of PLA-WS2 nanocomposites. In this work, we have studied the structural and thermal properties of PLA-WS2 nanocomposite films varying the concentration of WS2 NTs from 0 (neat PLA) to 0.6 wt%. The films were uniaxially drawn at 90 °C and annealed at the same temperature for 3 and 10 min. Using wide angle x-ray scattering, Raman spectroscopy and differential scanning calorimetry, we probed the effects of WS2 NT addition on the structure of the PLA films at various stages of processing (unstretched, stretching, annealing). We found that 0.6 wt% of WS2 induces the same level of crystallinity in as stretched PLA-WS2 as annealing in neat PLA for 10 min. These data provide useful insights into the role of WS2 NTs on the structural evolution of PLA-WS2 composites under uniaxial deformation, and extend their applicability to situations where fine tuning of PLA crystallinity is desirable.


2021 ◽  
Vol 37 (5) ◽  
pp. 88-95
Author(s):  
N.A. Petrov ◽  
S.N. Zorin ◽  
N.A. Biryulina ◽  
V.K. Mazo

Abstract- One of the promising food sources of biologically active substances is quinoa grain, which is valued for its high content of protein, sulfur-containing amino acids, lysine, fiber, and minerals. In addition, quinoa grain can be a valuable food source of polyphenolic compounds and phytoecdysteroids. The method for production of a concentrate of flavonoids and 20-hydroxyecdysone from quinoa grains sorbed on coagulated egg protein has been developed. The in vivo evaluation of efficacy of the developed food ingredient was conducted using male Wistar rats under immobilization stress and after exhausting physical exertion. The consumption of the food ingredient prevented an increase in the level of the main stress markers, catecholamines, in animals subjected to immobilization stress. The opposite effect was observed in animals that received the food ingredient after exhausting physical exertion: their levels of catecholamines were significantly higher than in the rest comparison groups. Using the Elevated Plus Maze and Open Field tests, it was shown that the consumption of the developed concentrate neutralized the negative effect of immobilization stress and treadmill exercise on anxiety in Wistar rats. The results obtained require additional study under conditions of preventive introduction of the food ingredient into the diet of intact animals, as well as a toxicological safety assessment. Key words: quinoa, 20-hydroxyecdysone, flavonoids, stress, immobilization, exhaustive physical exercise, catecholamines, corticosterone This work was supported by the Russian Scientific Foundation, grant no. 19-16-00107.


2009 ◽  
Vol 4 (3) ◽  
pp. 96-107 ◽  
Author(s):  
Claucia Fernanda Vol Souza ◽  
Janaina Guimaraes ◽  
Simone Hickmann Flores ◽  
Marco Antonio Zachia Ayub

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Ziyu Ge ◽  
Luming Yang ◽  
Fang Xiao ◽  
Yani Wu ◽  
Tingting Yu ◽  
...  

Graphene family nanomaterials, with superior mechanical, chemical, and biological properties, have grabbed appreciable attention on the path of researches seeking new materials for future biomedical applications. Although potential applications of graphene had been highly reviewed in other fields of medicine, especially for their antibacterial properties and tissue regenerative capacities, in vivo and in vitro studies related to dentistry are very limited. Therefore, based on current knowledge and latest progress, this article aimed to present the recent achievements and provide a comprehensive literature review on potential applications of graphene that could be translated into clinical reality in dentistry.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 328 ◽  
Author(s):  
Zhuang Ding ◽  
Lili Wang ◽  
Yangyang Xing ◽  
Yanna Zhao ◽  
Zhengping Wang ◽  
...  

Celecoxib (CLX), a selective COX-2 inhibitor, is a biopharmaceutics classification system (BCS) class II drug with its bioavailability being limited by thepoor aqueoussolubility. The purpose of this study was to develop and optimize CLX nanocrystalline(CLX-NC) solid dispersion prepared by the wet medium millingtechnique combined with lyophilizationto enhance oral bioavailability. In formulation screening, the resulting CLX-NC usingpolyvinylpyrrolidone (PVP) VA64 and sodiumdodecyl sulfate (SDS) as combined stabilizers showed the minimum particle size and a satisfactory stability. The formulation and preparation processwere further optimized by central composite experimentaldesign with PVP VA64 concentration (X1), SDS concentration (X2) and milling times (X3) as independent factors and particle size (Y1), polydispersity index (PDI, Y2) and zeta potential (Y3) as response variables. The optimal condition was determined as a combination of 0.75% PVP VA64, 0.11% SDS with milling for 90 min.The particle size, PDI and zeta potential of optimized CLX-NC were found to be 152.4 ± 1.4 nm, 0.191 ± 0.012 and −34.4 ± 0.6 mV, respectively. The optimized formulation showed homogeneous rod-like morphology as observed by scanning electron microscopy and was in a crystalline state as determined by differential scanning calorimetry and powder X-ray diffraction. In a storage stability study, optimized CLX-NC exhibited an excellent physical stability during six months’ storage at both the refrigeration and room conditions. In vivo pharmacokinetic research in Sprague-Dawley ratsdisplayed that Cmax and AUC0–∞ of CLX-NC were increased by 2.9 and 3.1 fold, compared with physical mixture. In this study, the screening and optimizing strategy of CLX-NC formulation represents a commercially viable approach forenhancing the oral bioavailability of CLX.


2007 ◽  
Vol 2 (1) ◽  
pp. S38-S44 ◽  
Author(s):  
Mahmoud Rouabhia ◽  
Vanessa Gilbert ◽  
Hongxum Wang ◽  
Muriel Subirade

2018 ◽  
Vol 1 (2) ◽  
pp. 226-236
Author(s):  
Mariana Branco ◽  
Ana R. Caseiro ◽  
Dina M. Silva ◽  
Irina Amorim ◽  
Alexandra Rêma ◽  
...  

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