Chitosan-Nanocellulose Composites for Regenerative Medicine Applications

2020 ◽  
Vol 27 (28) ◽  
pp. 4584-4592 ◽  
Author(s):  
Avik Khan ◽  
Baobin Wang ◽  
Yonghao Ni

Regenerative medicine represents an emerging multidisciplinary field that brings together engineering methods and complexity of life sciences into a unified fundamental understanding of structure-property relationship in micro/nano environment to develop the next generation of scaffolds and hydrogels to restore or improve tissue functions. Chitosan has several unique physico-chemical properties that make it a highly desirable polysaccharide for various applications such as, biomedical, food, nutraceutical, agriculture, packaging, coating, etc. However, the utilization of chitosan in regenerative medicine is often limited due to its inadequate mechanical, barrier and thermal properties. Cellulosic nanomaterials (CNs), owing to their exceptional mechanical strength, ease of chemical modification, biocompatibility and favorable interaction with chitosan, represent an attractive candidate for the fabrication of chitosan/ CNs scaffolds and hydrogels. The unique mechanical and biological properties of the chitosan/CNs bio-nanocomposite make them a material of choice for the development of next generation bio-scaffolds and hydrogels for regenerative medicine applications. In this review, we have summarized the preparation method, mechanical properties, morphology, cytotoxicity/ biocompatibility of chitosan/CNs nanocomposites for regenerative medicine applications, which comprises tissue engineering and wound dressing applications.

RSC Advances ◽  
2015 ◽  
Vol 5 (117) ◽  
pp. 97016-97026 ◽  
Author(s):  
Mariana-Dana Damaceanu ◽  
Luminita Marin

For the first time, the electropolymerization of 4,4′-(9-fluorenylidene)-dianiline and physico-chemical properties of the obtained polymer films are reported.


2020 ◽  
Author(s):  
Artur Schweidtmann ◽  
Jan Rittig ◽  
Andrea König ◽  
Martin Grohe ◽  
Alexander Mitsos ◽  
...  

<div>Prediction of combustion-related properties of (oxygenated) hydrocarbons is an important and challenging task for which quantitative structure-property relationship (QSPR) models are frequently employed. Recently, a machine learning method, graph neural networks (GNNs), has shown promising results for the prediction of structure-property relationships. GNNs utilize a graph representation of molecules, where atoms correspond to nodes and bonds to edges containing information about the molecular structure. More specifically, GNNs learn physico-chemical properties as a function of the molecular graph in a supervised learning setup using a backpropagation algorithm. This end-to-end learning approach eliminates the need for selection of molecular descriptors or structural groups, as it learns optimal fingerprints through graph convolutions and maps the fingerprints to the physico-chemical properties by deep learning. We develop GNN models for predicting three fuel ignition quality indicators, i.e., the derived cetane number (DCN), the research octane number (RON), and the motor octane number (MON), of oxygenated and non-oxygenated hydrocarbons. In light of limited experimental data in the order of hundreds, we propose a combination of multi-task learning, transfer learning, and ensemble learning. The results show competitive performance of the proposed GNN approach compared to state-of-the-art QSPR models making it a promising field for future research. The prediction tool is available via a web front-end at www.avt.rwth-aachen.de/gnn.</div>


2014 ◽  
Vol 70 (a1) ◽  
pp. C141-C141
Author(s):  
Ozen Ozgen ◽  
Engin Kendi ◽  
Semra Koyunoglu ◽  
Akgul Yesilada ◽  
Hwo-Shuenn Sheu

A significant part of medicine is based on the discovery and development of drugs. It is very important to know the crystal structure of pharmaceutical compounds for fundamental understanding of structure, physical and chemical properties. Many of these materials are available only as powders. So any structural information must be obtained from powder diffraction. I am going to present following the stages while solving the structure of C23H19N4OBr, 2-[3-phenyl-4(m-bromophenyl)-2-pyrazolin-1-yl]-3-methyl-4(3H)-quinazolinone, from 2-pyrazolines derivatives. The compounds are known to display various biological properties such as fungicidal insecticidal, anti bacterial, anti viral activities, pharmacological properties such as antiinflammatory agents and have industral properties(1). The powder diffraction data was collected with Debye Scherrer camera at the BL01C2 beamline at room temperature in National Synchrotron Radiation Research Center(NSRRC), Taiwan. X-ray of wavelength was 1.0333Å. This compound crystallizes in orthorhombic system space group P bca, Z=8, unit cell parameters of a=25.83(1)Å, b=15.55(5)Å, c=10.63(3)Å, and V=4266.0(10)Å3. Reliability factors were reached Rwp=0.075, Rp=0.053, RB=0.086 ve S=1.31 after Rietveld refinement.


2020 ◽  
pp. 089270572090765
Author(s):  
Ayesha Kausar

This review presents state-of-the-art progress in the field of polystyrene (PS)/graphene nanocomposite. Graphene is a monoatomic thick nanoallotrope of carbon. It has attracted tremendous research consideration owing to chemical functionalization aptitude and remarkable physical properties. Graphene has been used as a potential nanofiller to dramatically improve the performance of polymeric nanocomposite. PS is an important synthetic aromatic thermoplastic polymer. Graphene has been used to enhance the mechanical strength, thermal stability, electrical conductivity, and thermal conductivity of PS/graphene nanocomposite. Dispersion routes and synthetic methods of graphene and PS/graphene nanocomposite have also been reviewed. PS/graphene nanocomposites have been explored for anticorrosion, electromagnetic interference shielding, batteries, electrocatalysis, and microextraction applications. In spite of interesting developments, a lot remains to be done with regard to fundamental understanding of structure–property relationship and designing materials to operate for advanced high performance applications. This review is also concluded listing current challenges associated with processing and future perspectives of nanocomposite.


1971 ◽  
Vol 3 (6) ◽  
pp. 642-645
Author(s):  
V. G. Kulichikhin ◽  
B. L. Biber ◽  
E. B. Kostikova ◽  
D. N. Arkhangelskii ◽  
M. A. Ginzberg ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6191
Author(s):  
Alexandra-Elisabeta Stamate ◽  
Rodica Zăvoianu ◽  
Octavian Dumitru Pavel ◽  
Ruxandra Birjega ◽  
Andreea Matei ◽  
...  

Mechanical activation and mechanochemical reactions are the subjects of mechanochemistry, a special branch of chemistry studied intensively since the 19th century. Herein, we comparably describe two synthesis methods used to obtain the following layered double hydroxide doped with cerium, Mg3Al0.75Ce0.25(OH)8(CO3)0.5·2H2O: the mechanochemical route and the co-precipitation method, respectively. The influence of the preparation method on the physico-chemical properties as determined by multiple techniques such as XRD, SEM, EDS, XPS, DRIFT, RAMAN, DR-UV-VIS, basicity, acidity, real/bulk densities, and BET measurements was also analyzed. The obtained samples, abbreviated HTCe-PP (prepared by co-precipitation) and HTCe-MC (prepared by mechanochemical method), and their corresponding mixed oxides, Ce-PP (resulting from HTCe-PP) and Ce-MC (resulting from HTCe-MC), were used as base catalysts in the self-condensation reaction of cyclohexanone and two Claisen–Schmidt condensations, which involve the reaction between an aromatic aldehyde and a ketone, at different molar ratios to synthesize compounds with significant biologic activity from the flavonoid family, namely chalcone (1,3-diphenyl-2-propen-1-one) and flavone (2-phenyl-4H-1benzoxiran-4-one). The mechanochemical route was shown to have indisputable advantages over the co-precipitation method for both the catalytic activity of the solids and the costs.


2019 ◽  
pp. 28-44
Author(s):  
V. V. Parchenko

Modern medicine and pharmacy has at its disposal highly efficient synthetic drugs. Large extent of these drugs accounted for derivatives of 1,2,4-triazole. The purpose of the work was an attempt to summarize the literature in recent years related to the methods of synthesis and study of physico-chemical properties 3-thio- and 3-thio-4-amino derivatives of 1,2,4-triazole. Studies national scientists in recent years indicates prospects of the search in this direction, since this class of organic compounds is interest not only to scientists pharmaceutical, medical and veterinary field, but also among researchers of engineering, metallurgical and agricultural areas. 1,2,4-triazole derivatives are also widely used in practice for optical materials, photosensitizers are used as coloring agents, antioxidants, additives for fuels and oils, some of which are widely used as corrosion inhibitors for controlling various pests in agriculture. In addition, 1,2,4-triazole derivatives belong to the class low toxic or essentially non-toxic substances. The presence of a growing number of publications about methods of synthesis, reactions, physico-chemical and biological properties of 1,2,4-triazole, inspires scientists around the world search for perspective molecules of substituted 1,2,4-triazole. It should be noted that in spite of a sufficient amount of information about the derivatives of 1,2,4-triazole, some issues related to the generalization of data in the literature synthesis presented insufficient.


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