CANEVAROLO CIENCIA DOS POLIMEROS PDF

Request PDF on ResearchGate | On Jul 20, , Sebastião V. Canevarolo and others Sebastião Vicente Canevarolo Polímeros: Ciência e Tecnologia. Canevarolo Jr., S.V. Ciencia dos Polimeros. Sao Paulo: Artliber Editora Ltda. 2a edicao, ().. Mulimari, D. R.; Voorwald, H.J.C.; Cioffi, M.O. H.; Silva, M.L.C.P. . Polímeros vol no.3 São Carlos July/Sept. Sebastião V. Canevarolo Jr. pleasure to be appointed as Editor-in-Chief of “Polímeros: Ciência e Tecnologia”.

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Catheters are extensively used for coronary angiographies. These devices are long, thin, and flexible tubes of variable diameters that are made of the following polymer compounds: The objectives of this study are to identify changes that occur in the polymeric structure of the catheters, including an analysis of microcracks, fissures, cuts, perforations, roughness, and porosity in the internal and external layers after the first, second, third, and seventh reprocessing.

Five catheters of the same brand and manufacturer were selected for each analysis, except for the new and seventh catheters, which had only one sample. The catheters that we analyzed included new catheters, catheter reprocessed once 1stcatheters reprocessed twice 2ndcatheters reprocessed three times 3rdand catheters reprocessed up to seven times 7th. Samples were cut into small pieces and the scanning electron cuencia and infrared spectroscopy were used polimreos analysis.

Scanning electron microscopy SEM of reprocessed catheters revealed rougher surface with porosity, stainless steel wires, peeling of the inner layers, micropores, small holes, disordered cracks, cracks, grooves, microcracks, granular appearance, dots whitish, diffuse microcracks, desquamation, diffuse recesses, depressions, protrusions and deep crevices.

Infrared spectroscopy suggested a possible change in the chemical structures of the polymer. There was a directly proportional relationship between the reprocessing number and the carbonyl ratio.

The combined SEM and infrared analyses reveal that reprocessing damages polimers integrity of coronary angiography catheters. Therefore, the reprocessing of such catheters is not recommended.

Modern cardiology has revolutionized disease management through the introduction of more accurate diagnostic strategies and more effective and less invasive treatment techniques. The procedures that are performed in the hemodynamic laboratories of cardiology referral centers are relevant for the diagnosis and treatment of cardiovascular diseases; however, the associated technology and equipment are costly [ 1 ]. One of the most common hemodynamic procedures is coronary angiography cine-coronary angiography.

Reprocessing of Catheters Used for Coronary Angiography and Changes in the Polymeric Structures

The statistical data from a developed country show that 1, coronary angiographies andpercutaneous coronary interventions are performed annually.

In modern cardiology, pre-shaped catheters are extensively used for coronary angiographies.

The most dps devices are 2 mm wide and 1 m long and are inserted through the femoral or radial arteries [ 2 ]. Changes in hemodynamic catheter physical and chemical compositions may occur when they are reprocessed.

Editorial Polímeros, 3th Edition, Aug/

However, single-use device reprocessing is used for dental, medical, and hospital devices, including hemodynamic and electrophysiology catheters. The reprocessing follows the following steps: Unfortunately, limited healthcare resources are available in many countries, which motivate the search for inexpensive health strategies and hospital devices.

The reuse of coronary angiography catheters has been described in the past; therefore, we believe that a scientific evaluation of the changes that occur in pre-shaped catheters that are used in coronary angiography is canevarolp. We also analyzed the polymer structure of catheters and its mechanical functionality. In this study, angiographic catheters that are used during coronary angiography were evaluated.

Judkins left JL and Judkins right JR catheters that were pre-shaped in the distal end region were used to access the left coronary artery ostium during the cardiovascular angiographic studies. The reprocessing phases were performed as follows. In the first phase, the catheter was cleaned using a heparinized solution to remove blood residues.

In the second phase, the lumen was irrigated, and in the third phase, the external part of the catheter was cleaned manually. In the fourth diencia, the catheters were immersed in an antiseptic cabevarolo. In the fifth phase, the catheters were removed from the antiseptic solution and dried, first at ambient temperature and then in compressed air at variable pressure, as required. Catheters were subsequently sterilized using hydrogen peroxide plasma gas. The scanning electron microscope that was used in this analysis was performed using the following criteria: Five catheter samples ciecia evaluated, with one new catheter sample and four samples from catheters that were reprocessed one, two, three, or seven times.

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Samples were cut into small pieces of about 3 cm, which were mounted on stubs plates where samples were fixed to be read under the SEM using double carbon tape and coated with gold using a sputter coater. The images were obtained from cuts in the catheters, and this technique was used to protect the existing artifacts from the reprocessing procedure.

The same cut location and direction was used for all catheters, to standardize the technique and provide a starting point, since no other techniques were performed in the analysis area. The following parameters were used for the analysis: The data were normalized by the mean values, and in the infrared spectrum of each sample, three principal components were analyzed.

Each measurement was performed in triplicate. Five catheter samples were analyzed, with one sample from a new catheter and four from catheters that were reprocessed one, two, three, or seven times.

Samples were cut into small pieces of about 5 cm. A descriptive statistical analysis cnaevarolo the variables of interest of the study was performed. In addition, graphics were built demonstrating the results.

No interruptions were seen in the edges of new catheter canevaroolo. Figure 1 shows examples of canwvarolo modifications. We observed increased fissures, the presence of whitish pigments, and several scratches in samples that were reprocessed three times.

Figure 2 shows examples of catheters modifications. The sample that was reprocessed once showed a dry area and 20 whitish spots. The samples poimeros were reprocessed twice showed 10 fissures and three bulges.

The samples that were reprocessed three times showed seven fissures and 10 interruptions. The sample that cencia reprocessed seven times showed five scratches, 30 diffuse spots, and seven interruptions. Figure 3 shows examples of catheters modifications. In the infrared spectrum shown in Figure 4characteristic vibrations of the external side of angiographic catheters can be seen, as detailed in Table 1. The Figure 5 shows the spectra of new catheters and catheters that were reprocessed one, two, three, and seven times.

No new peaks were found, but ckencia intensity of the characteristic polyurethane peaks increased, which suggests a possible change in the chemical structures of the polymer. Infrared spectrum of angiographic catheters without and with the first, second, third and seventh reporcessing. The Figure 6 shows the carbonyl ratios of new catheters and catheters that were reprocessed one, canevqrolo, three, and seven times.

There is a directly proportional relationship between the reprocessing number and the carbonyl ratio. The Figure 7 shows the graph of the principal component analysis scores of new catheters and catheters that were reprocessed one, two, polimerow, and seven times. New and reprocessed samples were separated and reveal that a possible change in catheter structure occurred after sterilization.

Component analysis scores of new catheters and catheters that were reprocessed one, two, three, and seven times. The SEM is a type of electron microscope that is capable of producing high-resolution images of the surface of a sample, and examines the polimerso in such a way that the electron beam does not traverse the object. A narrow electronic beam is directed to the surface and scans the surface in a regular, side-to-side pattern.

When the scanning beam reaches the surface, it emits secondary electrons and synchronizes with the beam that produces the image on the monitor. Thus, a three-dimensional image of the sample surface can be constructed in the video, and micrographs can be obtained canearolo photographing the image.

The sample surface is then coated with a thin layer of metal, such as gold, white gold, carbon, to facilitate electron dispersion. A study that previously used SEM to analyze catheters showed that there was oxidative degradation of the polyamide polymer matrix when the material was exposed to hydrogen peroxide and the presence of micropores on the polymer surface, which became wider and led to the development of small micro-holes in the material. This analysis revealed increased wear of the angiographic catheters as the number of reprocessing increased [ 5 ].

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Previous studies have also suggested that the presence of imperfections on the surface of catheters cienciz be related to mechanical efforts and stresses that occur during the processing, handling, cleaning, and preparation of the material for sterilization. In addition, the single use of a catheter may canearolo in the accumulation of biofilms and endotoxins within microcracks, which may lead to infections and the development of thrombi in patients. In our study, the SEM showed, at a structural level, that the reprocessed catheters were damaged, which corroborates some data in the literature.

We identified that the catheters begin to change with the first reprocessing [ 4 ]. Infrared spectroscopy canevarolk one of the most important analytical techniques available today. One of the great advantages of this technique is that samples can be studied in almost any physical state. Liquids, polumeros, pastes, powders, films, fibers, gases, and surfaces can be analyzed based on judicious choices and sampling preparation techniques.

De la obtencion a la degradacion de PHB: Propiedades del material. Parte I.

The introduction of FTIR spectrophotometers dramatically improved the quality of infrared spectra and minimized the time required to obtain data. FTIR is used to obtain absorption or emission infrared spectrum of solids, liquids, or gases.

In diencia technique, a spectrometer simultaneously collects spectral high-resolution data cienfia a wide spectral range. FTIR is one of the most frequently recommended techniques for observing and evaluating degradation that occurs during catheter reprocessing [ 46 ]. The conventional infrared spectrum shows only the vibrations that lead to the rhythmic alteration of the dipole moment of a molecule. The alternating electric field, which is produced by the change of charge distributions that canevarllo the vibration, couples the molecular vibration with the oscillating magnetic field of the electromagnetic radiation, which results in radiant energy absorption.

In the present study, the ciencai functional groups that compose the catheters, polyurethane and polyamide, were identified in the FTIR spectra. It is important to emphasize that since the spectroscopy method did not polimsros the internal surface of the catheter, polytetrafluoroethylene could not be analyzed.

We observed that the reprocessing events were associated with changes in the components of the catheters [ cnevarolo8 ]. According to Oliveira D. The increases in peak intensity that were found in our study in catheters that were reprocessed many times polimerso be related to this phenomenon [ 9 ]. Infrared oxidation degradation studies of polyurethane blends showed that the absorption vos the bridging carbonyl region increased significantly with the development of oxidative degradation, as evidenced by the prevalence of cross-links in relation to chain scission [ 41011 ].

The increased absorbance ratio in the bridging carbonyl region is mainly due to the cross-linking effect that localizes to the polar regions of molecules and increases the participation of carbonyls in the formation of hydrogen bonds. This effect increases hydrogen bonds in the polymer chain during scission, which promotes the organization and crystallization of molecules, due to greater mobility.

Our study found that the higher are the number of reprocessing events, the higher are the carbonyl rates [ 4 ]. National Center for Biotechnology InformationU. Journal List Cardiol Res v. Published online Oct 7. Flavia Myrnaa Dinaldo C. Oliveira a Federal University of Pernambuco, Av. Author information Article notes Copyright and License information Disclaimer. Received Aug 31; Accepted Sep CopyrightMyrna et al. Abstract Background Catheters are extensively used for coronary angiographies.