Sterilization of Chitosan Membranes for Use as Biomaterial

2014 ◽  
Vol 805 ◽  
pp. 35-40 ◽  
Author(s):  
Imarally V.S.R. Nascimento ◽  
Rita de Cássia A. Leal ◽  
Marcus Vinícius Lia Fook ◽  
Roberta Costa Meira
Keyword(s):  
Ethylene Oxide ◽  
Ultraviolet Radiation ◽  
Physicochemical Properties ◽  
Functional Groups ◽  
Medical Devices ◽  
The Other ◽  
Complete Destruction ◽  
Chitosan Membranes

Sterilization is a procedure which promotes complete destruction or elimination of all forms of microorganisms. It is a fundamental stage in the processing of biomaterials, and functionality of any sterilization system must be determined by its effectiveness in exterminating microorganisms without harming or adversely affect the properties of medical devices. Some sterilization techniques can react with functional groups of the polymer leading to changes in the properties, affecting the biomaterial. This study aimed to develop chitosan membranes sterilize them by following methods: an autoclave, ethylene oxide, glutaraldehyde and ultraviolet radiation and characterized by FTIR, XRD and SEM. Based on the results of this study it can be concluded that the method of sterilization indicated for the membranes of chitosan is ethylene oxide because the other altered physicochemical properties thereof.

scholarly journals Behaviour of diferent types of chitosan membranes implanted in horses

2019 ◽  
Vol 39 (10) ◽  
pp. 837-842
Author(s):  
Vinícius M. Rollim ◽  
Gustavo M. Reginato ◽  
Letícia M. Fernandes ◽  
Julia A. Arantes ◽  
Eliana C.S. Rigo ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Ultraviolet Radiation ◽  
Subcutaneous Tissue ◽  
Experimental Period ◽  
Preparation Technique ◽  
Surgical Wound ◽  
Surgical Wounds ◽  
Different Types ◽  
Chitosan Membranes ◽  
Minimum Interval

ABSTRACT Chitosan has been successfully used as a biomaterial with several purposes in many species. In this study, chitosan membranes were produced with six different types of materials, and their behavior were evaluated upon implantation in the subcutaneous tissue of the flank of twelve healthy horses. We assessed chitosan membranes obtained from commercial chitosan, impregnated or not with silver nanoparticles, sterilized with ethylene oxide (CCEO, n=3; CCSNEO, n=3) or by ultraviolet radiation (CCUR, n=3; CCSNUR, n=3), and chitosan membranes obtained from squid gladius, sterilized with ethylene oxide (SCEO, n=6) or by ultraviolet radiation (SCUR, n=6). The same animals were randomly used in two experimental groups, with a minimum interval of 60 days between procedures, respecting the fact of only one flank side, left or right, be under evaluation by experimental period. After preparation of the membranes and implantation in the flank subcutaneous tissue of the horses, macroscopic and ultrasonographic evaluations of the implant regions were performed, as well as physical examination, blood count and fibrinogen measurement. No clinical or laboratory abnormalities were observed. All animals that received commercial chitosan membranes, regardless of the preparation technique, showed rejection to the biomaterials, considering that 100% of the surgical wounds presented dehiscence of suture and expulsion of the implants. The animals that received squid gladius chitosan membranes showed success in the treatment, with healing by primary intention of the surgical wound. We conclude that squid gladius chitosan membranes are biocompatible and biodegradable when implanted in the subcutaneous tissue of the flank of healthy horses.

scholarly journals Influence of Physicochemical Properties and Parent Material on Chromium Fractionation in Soils

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1073
Author(s):  
Claudia Campillo-Cora ◽  
Laura Rodríguez-González ◽  
Manuel Arias-Estévez ◽  
David Fernández-Calviño ◽  
Diego Soto-Gómez
Keyword(s):  
Physicochemical Properties ◽  
Contaminated Soils ◽  
Research Work ◽  
Parent Material ◽  
The Other ◽  
Oxidation States ◽  
Diethylenetriaminepentaacetic Acid ◽  
Remediation Strategies ◽  
Exchangeable Aluminum ◽  
Efficient Extraction

Chromium is an element that possess several oxidation states and can easily pass from one to another, so its behavior in soils is very complex. For this reason, determining its fate in the environment can be difficult. In this research work we tried to determine which factors affect the chromium fractionation in natural soils, conditioning chromium mobility. We paid special attention to the parent material. For this purpose, extraction experiments were carried out on spiked soils incubated for 50–60 days, using H2O, CaCl2 and diethylenetriaminepentaacetic acid (DTPA). The most efficient extraction rate in all soils was achieved using water, followed by CaCl2 and DTPA. We obtained models with an adjusted R2 of 0.8097, 0.8471 and 0.7509 for the H2O Cr, CaCl2 Cr and DTPA Cr respectively. All models were influenced by the amount of chromium added and the parent material: amphibolite and granite influenced the amount of H2O Cr extracted, and schist affected the other two fractions (CaCl2 and DTPA). Soil texture also played an important role in the chromium extraction, as well as the amounts of exchangeable aluminum and magnesium, and the bioavailable phosphorus. We concluded that it is possible to make relatively accurate predictions of the behavior of the different Cr fractions studied, so that optimized remediation strategies for chromium-contaminated soils can be designed on the basis of a physicochemical soil characterization.

A chemoinformatic analysis of atoms, scaffolds and functional groups in natural products

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Joelle Ngo Hanna ◽  
Boris D. Bekono ◽  
Luc C. O. Owono ◽  
Flavien A. A. Toze ◽  
James A. Mbah ◽  
...  
Keyword(s):  
Natural Products ◽  
Drug Discovery ◽  
Physicochemical Properties ◽  
Functional Groups ◽  
Atomic Composition ◽  
Synthetic Compounds ◽  
Chemical Libraries ◽  
Synthetic Drugs ◽  
Drugs Analysis ◽  
Chemical Class

Abstract In the quest to know why natural products (NPs) have often been considered as privileged scaffolds for drug discovery purposes, many investigations into the differences between NPs and synthetic compounds have been carried out. Several attempts to answer this question have led to the investigation of the atomic composition, scaffolds and functional groups (FGs) of NPs, in comparison with synthetic drugs analysis. This chapter briefly describes an atomic enumeration method for chemical libraries that has been applied for the analysis of NP libraries, followed by a description of the main differences between NPs of marine and terrestrial origin in terms of their general physicochemical properties, most common scaffolds and “drug-likeness” properties. The last parts of the work describe an analysis of scaffolds and FGs common in NP libraries, focusing on huge NP databases, e.g. those in the Dictionary of Natural Products (DNP), NPs from cyanobacteria and the largest chemical class of NP – terpenoids.

scholarly journals Rosuvastatin cocrystals: an attempt to modulate physicochemical parameters

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Venkata Deepthi Vemuri ◽  
Srinivas Lankalapalli
Keyword(s):  
Physicochemical Properties ◽  
Dissolution Rate ◽  
Functional Groups ◽  
Preliminary Investigation ◽  
Scale Up ◽  
Solvent Evaporation ◽  
Molar Ratio ◽  
The Novel ◽  
Formulation Development ◽  
Hydrogen Bond Interaction

Abstract Background The meager physicochemical properties like low solubility and low dissolution rate of rosuvastatin calcium remain as an obstruction for formulation development. In the present work, we explore the evolution of rosuvastatin cocrystal, which may offer the synergetic physico-chemical properties of the drug. Cocrystal crafting depends on two possible intermolecular interactions; heteromeric and the homomeric selection of compounds with complementary functional groups are contemplated as a possible cause of supramolecular synthons in cocrystal formation. Specifically, cocrystals of rosuvastatin with l-asparagine and l-glutamine with molar ratio (1:1) were fabricated by using slow solvent evaporation and slow evaporation techniques. Novel cocrystals of rosuvastatin-asparagine (RSC-C) and rosuvastatin-glutamine (RSC-G) cocrystals obtained by slow solvent evaporation were utilized for preliminary investigation and further scale-up was done by using the solvent evaporation technique. Results The novel cocrystals showed a new characteristic of powder X-ray diffraction, thermograms of differential scanning calorimetry, 1H liquid FT-NMR spectra, and scanning electron microscopy. These results signify the establishment of intermolecular interaction within the cocrystals. In both the novel cocrystals, rosuvastatin was determined to be engaged in the hydrogen bond interaction with the complementary functional groups of l-asparagine and l-glutamine. Compared with the pure rosuvastatin, RSC-C and RSC-G cocrystal showed 2.17-fold and 1.60-fold improved solubility respectively. The dissolution test showed that the RSC-C and RSC-G cocrystal exhibited 1.97-fold and 1.94-fold higher dissolution rate than the pure rosuvastatin in pH6.8 phosphate buffer respectively. Conclusion Modulation in the chemical environment, improvement in the solubility, and dissolution rate demonstrated the benefit of co-crystallization to improve the physicochemical properties of the drug. Graphical abstract

Physicochemical Properties of Micelles of Poly(styrene-b-2-vinylpyridine-b-ethylene Oxide) in Aqueous Solutions

2005 ◽  
Vol 78 (3) ◽  
pp. 529-533 ◽  
Author(s):  
Yuan Li ◽  
Anil Khanal ◽  
Nobuo Kawasaki ◽  
Yushi Oishi ◽  
Kenichi Nakashima
Keyword(s):  
Ethylene Oxide ◽  
Physicochemical Properties ◽  
Aqueous Solutions

scholarly journals A CONTRIBUTION TO THE HYDROCHEMISTRY AND WATER TYPOLOGY OF THE AMAZON RIVER AND ITS TRIBUTARIES

2019 ◽  
Vol 20 (72) ◽  
pp. 360-374 ◽  
Author(s):  
Maria do Socorro Rocha da Silva ◽  
Eduardo Antonio Ríos-Villamizar ◽  
Hillândia Brandão da Cunha ◽  
Sebastião Átila Fonseca Miranda ◽  
Sávio José Filgueiras Ferreira ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Physicochemical Properties ◽  
Amazon Basin ◽  
The Other ◽  
Amazon River ◽  
Left Bank ◽  
Guiana Shield ◽  
Ionic Charge ◽  
Physical Chemical ◽  
Geological Diversity

The geological diversity of the Amazon Basin, as well as the pluvial regime, influences the characteristics of the waters. To know the water types of the rivers of the Amazon basin, 288 superficial water samples were collected, 94 of them along the Amazon River and 194 in their tributaries, from March 2009 to September 2012. The physical, chemical, and physicochemical properties were analyzed. Rivers with pH between 6.5 and 7.6 and electrical conductivity (40.00 - 80.00 μS cm-1) are water bodies that are influenced by the Andean region (e.g., the Amazon River and some of its right bank tributaries). On the other hand, the rivers with pH in the range of 3.5 to 5.5 and conductivity <30.00 μS cm-1, which are Amazon River’s left bank tributaries, reflect the characteristics of the Guiana Shield. The rivers with pH (6.0 to 7.0), low ionic charge, and conductivity <40.0 μS cm-1, such as the lower Amazon River’s right bank tributaries (Tapajos and Xingu) which are influenced by the Central Brazilian Shield, and also the middle/upper Amazon River’s right bank tributaries (Tefé, Coari and Jutaí).

scholarly journals A Welcome to the New Journal, Journal of Advanced Therapies and Medical Innovation Science (j.ATAMIS).

2016 ◽  
Vol 1 ◽  
Author(s):  
Andrew Coats ◽  
Louise Shewan
Keyword(s):  
Venture Capital ◽  
Medical Devices ◽  
Medical Science ◽  
The Other ◽  
Proof Of Concept ◽  
Medical Innovation ◽  
Start Up ◽  
Advanced Therapies ◽  
Publishing Journal

<p>A new journal has been launched by Barcaray Publishing: Journal of Advanced Therapies and Medical Innovation Sciences (J.ATAMIS, www.j-atamis.org).  This journal fills a crucial gap in the literature – and in the cycle of advances in medical science, therapeutics and devices - covering the pipeline from idea through proof of concept studies and start-up funding to regulatory approval.  It will be multi-disciplinary and unusually we will have significant input from funders - both angel and venture capital-, start-up CEO’s, and regulators as well as medical scientists and triallists.  We have quite frankly a stellar editorial board, with leading lights of biotechnology, medical devices, new and established pharma as well as the “other side”, CEO’s and investors.  </p>

scholarly journals Isolation and Charactherization of Collagen from Swim Bladder Waste of Yellow-pike Conger (Muraenesox talabon)

2016 ◽  
Vol 19 (3) ◽  
pp. 222 ◽  
Author(s):  
I Wayan Darya Kartika ◽  
Wini Trilaksani
Keyword(s):  
Amino Acids ◽  
Body Weight ◽  
Physicochemical Properties ◽  
Functional Groups ◽  
Hydrothermal Process ◽  
Acid Extraction ◽  
Swim Bladder ◽  
Chemical Content ◽  
Wet Weight ◽  
Acid Process

<p>Indonesian capture fisheries production reached ± 6.4 million tons in 2014. This number was predicted<br />resulted a huge fishery waste, one of them was swim bladder that potentially contain collagen, so it needs to<br />be developed. This aim of this study was to determine the characteristics of the swim bladder (proportion<br />and chemical content) and collagen characteristics (yield and physicochemical properties) extracted from<br />the swim bladder cunang (Muraenesox talabon). Swim bladder waste had proportion 0.57 to 0.67% of whole<br />yellow-piked conger body weight and 24.74% protein/100 g wet weight (equivalent to 93.39% of protein/100<br />gram dry). The waste had a potency of collagen, which is characterized by the high proportion of the<br />amino acids glycine, proline, hydroxyproline and alain. Acid extraction and hydrothermal process resulted<br />collagen extracts, identified from a spectrum of amide I, amide II and amide III functional groups. Collagen<br />extracted with acid process contained a higher glycine than hydrothermal one, but instead hydrothermal<br />process produced extract with a higher proline, hydroxyproline and alanine composition.<br /><br /></p>

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