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31.
Suruchi Poddar Piyush Sunil Agarwal Ajay Kumar Sahi Neelima Varshney Kiran Yellappa Vajanthri Sanjeev Kumar Mahto 《应用聚合物科学杂志》2021,138(24):50569
The present study reports for first time the blending of psyllium husk (PH) powder/gelatin (G) in the polymer-rich composition of polyvinyl alcohol (PVA) to make an electrospinnable solution. The composite was prepared in 3 different ratios viz., 100% (wt/wt) (PVA + PH), 75% + 25% (PVA + 75PH + 25G) (wt/wt) and 50% + 50% (PVA + 50PH + 50G) (wt/wt) in 6% PVA solution. Optimum electrospinning parameters were evaluated for all the prepared blends. The fabricated nanofibers were characterized by scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared, differential scanning calorimetry, porosity percentage, and fiber orientation using ImageJ software. A qualitative in vitro degradation study at room temperature is supported by SEM images. The cellular interactions were characterized by MTT assay of NIH-3T3 fibroblast cells for 2 and 4 days with an optimum cell growth of >50% by fourth day of culture and long-term cultivation of L929-RFP cells was observed for 10 days. The nanofibers were formed in the range of 49–600 nm. PVA + 75PH + 25G when cultured with L929-RFP cells exhibited highest fluorescence intensity and thus supported cellular proliferation significantly. Based on the results obtained from various analyses, we anticipate that fabricated psyllium-based nanofiber can be used as a promising candidate for wound healing and other biomedical applications. 相似文献
32.
Gabriela Brunosi Medeiros Paulo Ricardo de Souza Karina Miyuki Retamiro Celso Vataru Nakamura Edvani Curti Muniz Elisângela Corradini 《应用聚合物科学杂志》2021,138(36):50898
The production of polymer fibers from the combination of zein and PEO might have great potential in the field of biomaterial. Zein/PEO fibers were obtained in this work through solution electrospinning. An experimental design, 24-1, was used for evaluating the influences of PEO content in the blend, distance from the needle tip to the collector, applied electric voltage and solution flow for average fiber diameter and relative-yield process. Beyond this, the relationship between PEO content in the blend and the fiber properties were evaluated through FTIR, DSC, TG, tensile tests, and cytotoxic tests. The factor that exerts the greatest effect on the average fiber diameter response was the electrical voltage. The increase in PEO content in the blend decreased the thermal stability and increased the degree of the fibers' crystallinity. The mechanical tests showed that fibers with higher elongation were obtained at richer PEO blends. The fibers presented cytocompatible characteristics. 相似文献
33.
This work was done to assess the role of precursors (agro and graphite) on performance of carbon nanoallotropes-biomacromolecules composite as drug delivery for controlling the release of niacin. In this respect graphene oxide and bagasse-based carbon oxide were synthesized and chelated with chitosan (Cs-GO and Cs-Co). These gel composites were characterized by many techniques [morphology, differential scanning calorimetry, Fourier-transform infrared spectroscopy, swelling, encapsulation efficiency (EE) and loading (L) % of niacin. Another series of experiments was carried out for studying the role of replacing part of carbon nanoallotrope by carboxymethyl cellulose (CMC) on performance of produced drug carries, these systems were coded as Cs-GO-CMC and Cs-Co-CMC. The data showed that, the Cs-GO gel composite provided maximum release of NA, at 5 h, for pH's simulated gastric and intestinal fluids; pH. 2.1 and pH 7.4 (1120 mg/L and 757 mg/L). The incorporation of CMC is not acceptable as it provided low drug release together with burst release of NA-drug, and consequently possible caused tissue irritation or toxicity in the human body. The Cs-GO and Cs-CO systems with relatively low drug loading were recommended for their better controllability system to NA release, which prolonging benefit of human with niacin. The NA release from all investigated gels followed Fickian and non-Fickian diffusion mechanisms. 相似文献
34.
Gualberto Antonio Zumbardo-Bacelis Linnette Aracely Meza-Villegas Cesar Antonio Pérez-Aranda Rossana Vargas-Coronado Omar Castillo-Cruz Vanessa Montaño-Machado Diego Mantovani Juan Valerio Cauich-Rodríguez 《应用聚合物科学杂志》2021,138(42):51247
Polymer blends based on Tecoflex™ and an experimental aliphatic polyurethane (HMDI-PCL-arginine stands for 4,4 (metylene-biscyclohexyl) isocyanate - poly (ε caprolactone) diol, SPUUR stands for segmented poly(urea)urethanes using amino acid of L-Arginine as chain extender) were obtained by solvent casting, and further studied by fourier transform infrared (FTIR) and Raman spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, and X-ray diffraction (XRD). Their biological performances were assessed in terms of hemocompatibility and Human umbilical vein endothelial cell (HUVEC) cytotoxicity. Tensile properties of dumbbell specimens were compared to longitudinal and circumferential tensile properties of tubular vascular graft. FTIR showed that as the SPUUR content increased in the blend, absorptions at 2860 cm−1 increased, carbonyl absorptions at 1724 cm−1 broaden and the small peak at 2796 cm−1, typical of Tecoflex™ disappeared. Raman spectroscopy showed that the low intensity carbonyl absorption at 1724 cm−1 also increased with SPUUR content. DSC allowed detection of PCL soft segment melting (Tm = 50°C) in agreement with X-ray reflections at 21.3° and 23.6°, assigned to SPUUR. However, no improvements in thermal stability were detected by TGA by blending. The addition of SPUUR to Tecoflex™ improved hemocompatibility and HUVEC cytotoxicity. The vascular grafts performance showed that 40% SPUUR blends exhibited the highest force in the longitudinal test whereas 50% SPUUR blends showed the highest circumferential force. Pressure burst strength was higher than 1000 mmHg for all blends. Overall, these blends can be used for high caliber vascular grafts. 相似文献
35.
The compulsion to use bioplastics has increased significantly today. One of the important aspects of plastics is their recyclability. Therefore, the important question of this research is that although bio-based compounds containing starch are sensitive to thermal-mechanical recycling processes, are such products thermally recyclable? To answer the question, polypropylene (PP)/thermoplastic starch (TPS) compound granules were extruded up to five times, and in the other part, single-extruded granules were blended at different ratios with virgin granules by extrusion. In order to characterize these samples, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, rotational disc rheometry, tensile properties, and appearance evaluation were used. The results showed that it is possible to recycle PP/TPS granules up to four times repetition of the extrusion operation and the fifth repetition also showed slight changes. There was also a blend of single-extruded granules with virgin material up to a 50:50% composition without significant variation. 相似文献
36.
Anastasiia N. Andriianova Lyaysan R. Latypova Liliya Ya. Vasilova Sofia V. Kiseleva Vladimir V. Zorin Ildus B. Abdrakhmanov Akhat G. Mustafin 《应用聚合物科学杂志》2021,138(47):51397
This work presents a detailed study on the effect of various functional groups both at the ortho position of the aromatic ring and in the amino group of PANI on the antibacterial properties of polymers against gram-positive (Bacillus subtilis) and gram-negative (Pseudomonas aureofaciens) microorganisms. It was found that incorporation of methyl, methoxy, or pentyl groups into the ortho-position of PANI did not increase the antibacterial activity but in most cases causes a significant decrease in the antibacterial properties of functionally substituted polyanilines. At the same time, PANI derivatives modified by incorporation of pentyl groups into the amino group were found to be more efficient antibacterial compounds against both gram-positive and gram-negative microorganisms than the original polymer. It was also found that N-substituted PANI derivatives manifest not only bactericidal but also bacteriostatic properties toward the test microorganisms. Varying the nature and position of the substituent allowed us to conclude that the synthesis of various N-substituted PANI derivatives with a high degree of doping is the most promising approach to PANI modification for application in bacterial growth inhibition. 相似文献
37.
Tuberculosis (TB) is one of the deadliest diseases known to man and ranks among the top ten global causes of fatalities. Children often develop a paucibacillary form of this disease which makes diagnosis arduous even with the aid of sophisticated techniques. In these cases, the concentration of bacteria in their sputum falls below the lowest limit of detection for sputum smear microscopy, the technique predominantly used in developing countries. In this study we aim to test the hypothesis that modifying a polymer, often used in buccal swabs, could assist in creating a capturing and concentrating oral swab for Mycobacterium tuberculosis (Mtb), the pathogenic bacterial species responsible for TB. Such a device will assist in meeting the detection limit and allow for rapid detection of the disease. The polymer used was a micro fibrous form of poly(ethylene terephthalate) (PET) which was surface functionalized with Concanavalin A (Con A), a lectin based adhesin with an affinity for the mannose groups on the Mtb cell wall. The functionalization was mediated with glutaraldehyde as bioconjugate molecule and found to produce a surface uniformly covered with Con A. Affinity studies between the modified fibers and the Mycobacterium bovis bacillus Calmette-Guérin (BCG), as Mtb mimic, were conducted to evaluate the capturing abilities of the substrate. The results indicate that the fibers avidly captured BCG and that the fibrous matrix aided in its function. Dilution studies showed successful capturing of the bacterial species at concentrations characteristic of paucibacillary cases. In this study a commercial polymeric material was successfully surface modified with a biological entity to create a substrate to which Mtb could adhere and accordingly be captured. 相似文献
38.
This study evaluated the effectiveness and efficiency of two food-grade multifunctional epoxies chain extenders (CE) in branching PLA and improving its foamability. Both CE grades were effective in branching PLA causing increased end mixing torque, shear, elongational viscosities, molecular weight but decreased crystallinity of poly(lactic acid) (PLA) with CE content, due to chain entanglements. CE with low epoxy equivalent weight (EEW) was more efficient than the counterpart with high EEW due to its high reactivity. Neat PLA foams showed poor cell morphology with areas without nucleated cells and had a low expansion, owing to its low elongational viscosity. By contrast, there was a considerable change in the morphology of the PLA foam structure caused by its branching. Chain-extended PLA foams had uniform cell morphology with a high void fraction (up to ~85%) and expansion ratio (an eightfold expansion over unfoamed PLA) due to their high elongational viscosities, suggesting that melt properties of branched PLA were appropriate for optimum cell growth and stabilization during foaming. Overall, CE with low EEW was the most effective grade and 0.25% the optimum content that provided appropriate melt viscosity to produce PLA foams with a homogeneous structure, fine cells, high void fraction, high volume expansion ratio, and cell-population density. 相似文献
39.
镁表面改性及其在仿生体液中的耐蚀行为 总被引:9,自引:1,他引:9
对纯度为99.9%的纯镁表面改性,以提高纯镁在仿生模拟体液(SBF)中的耐腐蚀性能.其过程为:室温下将纯镁在初始pH值为9.3的过饱和NaHCO3-MgCO3混合溶液中浸泡24 h,然后在773 K保温10 h;再将试样放入(37±0.5)℃的SBF溶液中浸泡14 d.X射线衍射分析表明:纯镁在NaHCO3-MgCO3混合溶液中浸泡后,表层主要为MgCO3·3H2O晶体;热处理后,MgCO3·3H2O晶体转变成MgCO3和Mg(OH)2的混合物.EDS分析表明,距表面厚约20 μm的基体被氧化,形成了耐蚀氧化层.经碱热处理的试样在SBF溶液中浸泡14 d后,经X荧光能谱(XPF)分析可知表层沉积出Ca/P摩尔比为1.858的钙磷基沉淀.本阶段实验表明,碱热处理可以显著提高纯镁在仿生环境下的耐腐蚀性能. 相似文献
40.
Il Song Park Tae Gyu Woo Min Ho Lee Seung Geun Ahn Myung Sik Park Tae Sung Bae Kyeong Won Seol 《Metals and Materials International》2006,12(6):505-511
Anodic oxidation is the process of creating a titanium oxide layer with various defects more dense and stable. In this study,
a dense, stable and porous oxide layer was formed using anodic spark oxidation on pure titanium surface and hydroxyapatite
crystals were formed on its surface via a hydrothermal treatment. A mixture of 0.02M−GP (Glycerolphosphate disodium salt)
and 0.2M-CA (Calcium acetate) was used as an electrolyte. By increasing the anodizing voltage to 220, 260, 300, and 360 V,
the effects of the anodizing voltage were examined by evaluating the film properties after anodization and a hydrothermal
treatment. Breakdown occurred around 230 V. As the voltage increased after breakdown, the pore size increased. After the hydrothermal
treatment, the amount of HA crystal precipitation was also increased as the voltage increased. The mean surface roughness
(Ra) of the anodizing surface was also increased as the voltage increased. The Ra value was larger in the hydrothermally treated
group compared with the group treated with anodization as a result of the HA crystals present on the surface after the hydrothermal
treatment. Corrosion resistance of the surface modified by anodization was significantly increased in a saline solution compared
to that for the non-treated group; this increased further after the hydrothermal treatment. These increases were most likely
due to a thick stable oxide layer formed through anodization. Thus, it is believed that titanium with its surface modified
through anodic spark oxidation would be a suitable biomaterial due to its corrosion resistance and biocompatibility. 相似文献